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Study of Fiber Reinforced Polymer Materials in Reinforced Concrete Structures As Reinforced Bar SEMINAR-I REPORT Girish Kumar Singh SPA/NS/BEM/612 II nd SEMESTER DEPARTMENT OF BUILDING ENGINEERING AND MANAGEMENT SCHOOL OF PLANNING AND ARCHITECTURE New Delhi – 110002 MAY 2015

Study of Fiber Reinforced Polymer Materials in Reinforced Concrete Structures As Reinforced Bar

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Page 1: Study of Fiber Reinforced Polymer Materials in Reinforced Concrete Structures As Reinforced Bar

Study of Fiber Reinforced Polymer Materials in

Reinforced Concrete Structures As Reinforced Bar

SEMINAR-I

REPORT

Girish Kumar Singh SPA/NS/BEM/612

IInd SEMESTER

DEPARTMENT OF BUILDING ENGINEERING AND MANAGEMENT

SCHOOL OF PLANNING AND ARCHITECTURE

New Delhi – 110002

MAY 2015

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CERTIFICATE

Certified that this Project Seminar titled "Study of Fiber Reinforced Polymer Materials in

Reinforced Concrete Structure As Reinforced Bar" submitted by Er. Girish Kumar Singh in

partial fulfillment for the award of the degree of Master in Building Engineering and

Management at the School of Planning and Architecture, New Delhi, is a record of student's

work carried out by him under my supervision and guidance. The matter embodied in this

seminar work, other than that acknowledged as reference, has not been submitted for the

award of any other degree or diploma.

Prof. Dr.V.Thiruvengadam Prof. Dr. V.K. Paul

Visiting Faculty & Seminar Guide Prof. & Head of the Department

Building Engineering & Management Building Engineering & Management

School of Planning and Architecture. School of Planning and Architecture

New Delhi. New Delhi

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ACKNOWLEDGEMENT

I would like to sincerely thank Prof. Dr. V.K. Paul, Head of the Department of Building

Engineering and Management, Prof. Kuldeep Chander, for helping in successfully

completing the seminar work.

I take this opportunity to express my gratitude to my guide, Prof. Dr.V.Thiruvengadam,

faculty, Department of Building Engineering and Management, for his constant and generous

support throughout the Seminar. His inputs and guidance proved vital to shape the Seminar

in the desired form.

My sincere thanks to Prof. Dr. V.K. Paul, Head of the Department of Building Engineering

and Management, for his valuable suggestions at various stages in the Seminar work.

I thank my family, Mom & Dad, for believing in me and incessantly encouraging me to take

up this course. They are and shall always be my greatest source of strength and a belief in

myself. May I always stand tall to all their expectations and excel beyond their dreams.

New Delhi

May 2015 Girish Kumar Singh

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ABSTRACT

Around the world we are having several upcoming projects near the coast line so the

study is needed to understand the effect on cost when we use FRP in the structure because FRP

is a costly material compare to steel which may or may not increase the structure overall cost.

It will may or may not increase the structure cost because if we use FRP in a structure then we

can avoid the problem that we face in a structure caused due to corrosion which reduce strength

of the structure, foundation loosing plaster from the surface of the reinforced section due to

expansion caused due to rusting as well as in building envelopes.

The objectives of this seminar report are to study about FRP Manufacturing and its properties,

study about the various applications of FRP, design and analyze a FRP member, Finite element

analysis of a simple beam using FRP as a reinforcement, role of FRP in the sustainable world,

to find out the cost benefit of the elements used in a corrosive environment structure which can

be replaced by the FRP.

This study will cover all the forms of FRP that can be used in a building and give a brief about

FRP rebars its properties, design, analysis, uses and the effect on cost of a build during

construction as well as the cost analysis of the structure.

This study will give an idea on the advantage of FRP over steel when we are using FRP in a

corrosive environment like coast line and it will give an initial idea to the designer about the

advantage and disadvantage of FRP over steel.

In the final part of this seminar report analysis results are used to give a base that FRP can

sustain in structure as FRP reinforced bar and an example of a LCC is also used to give a

satisfactory conclusion and on the final page the summery of the seminar is present.

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

Contents Chapter 1 - Introduction ................................................................................................................................. 6

1.1 General ................................................................................................................................................. 6

Table 1.1 Merit Comparison and Ratings for FRP and Steel ........................................................................ 9

Table 1.2 FRP Merits and Suitability of Applications .................................................................................. 9

Table 1.3 FRP Use and Suitability for Marine Applications ....................................................................... 10

1.2 Need of Study ..................................................................................................................................... 11

1.3 Aim ...................................................................................................................................................... 11

1.4 Objectives ........................................................................................................................................... 11

1.5 Scope of study ..................................................................................................................................... 11

1.6 Methodology ....................................................................................................................................... 12

1.7 Seminar Organization ............................................................................................................................. 12

Chapter 2: Literature Review....................................................................................................................... 15

1. General ........................................................................................................................................... 15

2. Codes & Published Papers .................................................................................................................... 15

2.1 State-of-the-Art Report on Fiber Reinforced Plastic (FRP) Reinforcement for Concrete Structures (ACI 440.04r, 2002) ................................................................................................................. 15

2.2 Serviceability of Concrete Beams Prestressed By fiber Reinforced Plastic Tendons (By Amr. A Abdelrahman1995) .................................................................................................................................. 16

2.3 Retrofitting of Existing Bridge Using Externally Bonded FRP Composite Applications and Challenges (MEDIA) .................................................................................................................................. 16

2.4 The role of FRP composites in a sustainable world (Jain, 2009) ................................................ 17

2.5 Bridge decks of fibre reinforced polymer (FRP): A sustainable solution ................................. 18

2.6 Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures (440, Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures, 2008) ....................................................................... 18

2.7 Guide for the Design and Construction of Structural Concrete Reinforced with FRP Bars (ACI 440, 2006) ........................................................................................................................................... 19

Chapter : 3 Materials Introduction (FRP) .................................................................................................. 20

3.1 History ............................................................................................................................................ 20

3.2 Manufacture Process ..................................................................................................................... 22

3.2.1 General ................................................................................................................................... 22

3.2.2 Manufacturing Process ................................................................................................................. 23

3.2.3 Fibre ................................................................................................................................................ 23

3.2.4 Forming processes ................................................................................................................. 26

• Glass fibre material ....................................................................................................................... 30

• Carbon fiber ................................................................................................................................... 30

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 1 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

• Aramid fiber material ................................................................................................................... 31

3.6.1 Corrosion Resistance ..................................................................................................................... 31

3.6.2 High Strength, Lightweight .......................................................................................................... 32

3.6.3 Dimensional Stability .................................................................................................................... 32

3.6.4 Parts Consolidation and Tooling Minimization. ......................................................................... 32

3.6.5 High Dielectric Strength and Low Moisture Absorption ........................................................... 32

3.6.6 Minimum Finishing Required ...................................................................................................... 32

3.6.7 Low to Moderate Tooling Costs ................................................................................................... 32

3.6.8 Design Flexibility ........................................................................................................................... 32

3.6.9 Thermal conductivity .................................................................................................................... 33

3.6.10 EMI /RFI Transparency ............................................................................................................... 33

3.6.11 Physical properties ......................................................................................................................... 33

• Density ............................................................................................................................................ 33

• Coefficient of thermal expansion .................................................................................................. 33

3.6.12 Mechanical properties and behavior ........................................................................................... 34

• Tensile behavior ............................................................................................................................. 34

• Compressive behavior ................................................................................................................... 36

• Shear behavior ............................................................................................................................... 38

• Bond behavior ................................................................................................................................ 38

3.6.13 Time-dependent behavior ............................................................................................................. 39

• Creep rupture ................................................................................................................................ 39

• Fatigue ............................................................................................................................................ 40

• Effects of high temperatures and fire ........................................................................................... 43

3.6.14 Chemical Properties ...................................................................................................................... 44

3.7 Applications .................................................................................................................................... 45

3.7.1 Applications of FRP Composites in Industrial Construction ............................................ 45

3.7.2 Application of FRP Composite Systems in Strengthening . ....................................................... 47

3.7.3 Army, Marine, and Related Applications ............................................................................ 51

3.7.4 FRP Pipes for Marine Applications ..................................................................................... 52

3.7.5 FRP Piling .............................................................................................................................. 53

3.7.6 Other FRP applications ......................................................................................................... 54

3.7.7 FRP Design, Development and Field Implementation by CFC-WVU and Others .......... 55

3.7.8 Application of FRP as Rebar ................................................................................................ 57

Chapter 4 Code Provision ............................................................................................................................. 59

1.1 Standard test methods for FRP bars and laminates ................................................................... 59

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 2 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

Chapter 5 Manual Design of FRP Beam ..................................................................................................... 61

Chapter 6 Analysis of Beam Using FEM .................................................................................................... 74

Finite element model of concrete SOLID65 Description: ...................................................................... 76

SOLID65 ................................................................................................................................................. 76

Input Summary ...................................................................................................................................... 77

LINK8 Input Summary ......................................................................................................................... 78

Chapter 7 Costing .......................................................................................................................................... 92

INTRODUCTION ........................................................................................................................................... 92

View of the Okinawa Road Park Bridge ...................................................................................................... 93

THE STRUCTURES FOR THE CASE STUDY............................................................................................. 93

Model cases of FRP and PC bridges ............................................................................................................ 94

FRP footbridges ......................................................................................................................................... 95

Table 2: Model cases of PC bridges and initial costs (Unit: 1000JPY) .................................................. 96

Table 3: Model cases of FRP bridges and initial costs (Unit: 1000JPY) .............................................. 96

CASE-4 ........................................................................................................................................................ 96

CASE-5 ........................................................................................................................................................ 96

Modified points for the superstructure ......................................................................................................... 96

Standard FRP bridge based on the real bridge ............................................................................................. 96

Aluminum handrail ...................................................................................................................................... 96

Change of joint parts of the main girders ..................................................................................................... 96

Sharing the mold by 2 bridges ..................................................................................................................... 96

Initial cost for the superstructure .................................................................................................................. 96

73,600 96

62,350 96

Substructure system ..................................................................................................................................... 96

Pier 1: 2 Steel pipe piles (φ500mm-9mm, L=15.0m) ................................................................................... 96

Pier 2: 4 Steel pipe piles (φ500mm-9mm, L=18.0m) Pier 3: 2 Steel pipe piles (φ500mm-9mm, L=12.0m) 96

Initial cost for the substructure ..................................................................................................................... 96

6,910 96

Total Initial costs.......................................................................................................................................... 96

80,510 96

69,260 96

Maintenance costs ...................................................................................................................................... 97

FRP footbridge ........................................................................................................................................... 97

LCC 98

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 3 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

Table 4: LCC results of both PC and FRP footbridges (Unit: 1000JPY) ............................................... 99

CONCLUSION ................................................................................................................................................ 99

Chapter 8 Summery .................................................................................................................................... 101

Bibliography ................................................................................................................................................... 102

LIST OF FIGURE

Figure 1 Formation Process Of FRP ............................................................................................................ 22

Figure 2 Structure of FRP ................................................................................................................................ 23

Figure 3 Stress Strain Curve Fro FRP ........................................................................................................ 36

Figure 4 FRP Pultruded sections and chemical platform with these products ........................................ 46

Figure 5 FRP composite tanks: a – horizontal tanks [7]; b – vertical tanks [8]. ...................................... 46

Figure 6 Large scale GFR polyester dome and skylight. ........................................................................... 46

Figure 7 Folded skylight on an industrial workshop; double curved shells for an industrial roof. ....... 47

Figure 8 – a – Blades made of glass fibre reinforced polymer (GFRP) [4]; b – FRP composite

components for an offshore platform [6]. .................................................................................................... 47

Figure 9 Strengthening solutions using FRP based solutions for an industrial hall: a – wall

strengthening with bidirectional strips (1) and unidirectional strips (2); b – column strengthening

using discrete strips (3), continuous wrapping (4) and combined discrete and continuous wrapping (5);

c – discrete bending strengthening solutions for reinforced concrete (RC) girders and continuous

membranes (6); d – shear strengthening solutions for RC girders using bottom flange clamping of

inclined strips for runway girders (7) and (8) and U-shaped bands (9); e – strengthening solution for

main transverse girders including end textile clamping (10), plate bonding (11) and discrete clamping

made of composite strips (12); f – plate bonded ribs for roof elements (13). .......................................... 49

Figure 10 Composite based strengthening solutions for industrial chimneys: a – wrapping with

carbon fibre balanced fabric; b – confinement with composite hoop strips; c – helicoidal spiral made

of composite cable; d – prefabricated composite membranes [14]. .......................................................... 50

Figure 11: Very large FRP pipe systems from Future Pipe Industries (www.futurepipe.com) ............. 52

Figure 12 Composite marine piles from different manufacturers were tested. Shown in pictures:

SEAPILE, PPI and Trimax piles, (Juran and Komornik, 2006) ............................................................... 53

Figure 13 Composite marine piles from different manufacturers were tested. Shown in pictures:

SEAPILE, PPI and Trimax piles, (Juran and Komornik, 2006) ............................................................... 54

Figure 14 Boeing 787 Dreamliner, the world's first major commercial airliner to use composite

materials for most of its construction (www.boeing.com) .......................................................................... 54

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 4 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

Figure 15 FRP Design and Applications by the CFC-WVU, (Top L to R) – i) FRP dowels in highway

pavement (Elkins, WV), ii) FRP reinforcement for concrete highway pavement (Charleston, WV), and

iii) FRP thermoplastic tie for railroads (Moorefield, WV); (bottom L to R) - i) FRP pavement panels

(Morgantown, WV, iii) thermoplastic FRP offset block for guardrails, (Morgantown, WV) (Courtesy:

CFC-WVU)..................................................................................................................................................... 55

Figure 16 FRP bridge deck shapes designed and field implemented in WV and Ohio by the CFC-

WVU (Courtesy: CFC-WVU) ....................................................................................................................... 56

Figure 17 FRP application for ship decks L); successful testing of fire resistant FRP panel at 5800

degree F with acetylene torch for 5 minute at CFC-WVU. (Courtesy: CFC-WVU) ............................... 56

Figure 18 FRP Inspection Walkway Blennerhassett Bridge, Parkersburg, WV (Courtesy: CFC-

WVU) .............................................................................................................................................................. 57

Figure 19 Examples of FRP application for bridges: (Top L to R)- i) Carbon cables used in bottom

chord, Kleine Emme Bridge, Switzerland (Courtesy: Dr. Urs Meier); ii) FRP pedestrian bridge over

9th Street, NY; (bottom L to R)- iii) Neal Bridge, Maine with FRP tubes (courtesy: NYTimes.com); iv)

Proposed FRP Pedestrian Bridge at West Virginia University, Morgantown) ....................................... 57

Figure 20 Commercially available GFRP reinforcing bars ....................................................................... 58

Figure 21 Solid 65 Geometry ........................................................................................................................ 76

Figure 22 LINK8 GEOMETRY ................................................................................................................... 78

Figure 23 Model Of ANSYS ......................................................................................................................... 88

Figure 24 Model Showing 14.4 kN/m UDL with simply supported at both ends..................................... 89

Figure 25 Nonlinear analysis graph during analysis .................................................................................. 89

Figure 26 Stress along the length of the beam. ........................................................................................... 90

Figure 27 Top stress in the beam.................................................................................................................. 90

Figure 28 Deflection in the beam .................................................................................................................. 91

Figure 29 Initial crack in the beam Figure 30 Final crack of the beam ............................................ 91

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 5 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

Chapter 1 - Introduction

1.1 General Fiber-reinforced plastic- FRP is a composite material made of a polymer matrix reinforced with

fibers. The fibers are usually glass, carbon, basalt or aramid, although other fibers such as paper or

wood or asbestos have been sometimes used. The polymer is usually an epoxy, vinyl

ester or polyester thermosetting plastic, and phenol formaldehyde resins are still in use. FRPs are

commonly used in the aerospace, automotive, marine, construction industries and ballistic armor.

First time FRP was introduced in 1980s and after 35 years the construction industries are still using

steel and aluminum in the building. Although FRP is costlier than the steel and other building metals

but the property of FRP makes it a very reliable and useful material which can be used in the building.

According to (Chris BURGOYNE, 2007) the cost of CFRP is about 4.21 times, GFRP is 2.25 times

and AFRP is 4.21 times of steel but it was the rate analysis done in year 2007 now we have so many

industries which manufacture FRP in most of the countries like Japan, china, India etc.

So this paper is all about the cost benefit analysis of a building situated in the corrosive environment

where we can replace contemporary material with FRP

There are three type of FRP materials in the market which are:

1. Carbon Fiber Reinforced Plastic

2. Glass Fiber Reinforced Plastic

3. Aramid Fiber Reinforced Plastic

Fiber Reinforced Polymer (FRP) composites with fibers/fabrics bonded together with the help of

organic polymers (resin system) are being referred to as the materials of 21st century because of

many inherent advantages. Some of the inherent advantages of FRPs over traditional materials are:

(1) Superior thermo-mechanical properties such as high strength and stiffness, and light weight,

(2) Excellent corrosion resistance,

(3) Magnetic transparency,

(4) Design flexibility (tailorability),

(5) Long-term durability under harsh service environments.

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 6 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

Composites can be three to five times stronger, two to three times stiffer, and three to four times

lighter than metals such as steel and aluminum. In addition, composites are dimensionally stable,

aesthetically pleasing and cost effective with better durability and lower maintenance than the

conventional mateirals. In the United States of America, FRP composites applications to civil

infrastructure started in the form of marine structures, piers, tanks and pilings for military

requirement. Since then, major field implementations of FRP composites have taken place in bridges,

roads, marine structures and retrofitting of structures, with great success in retrofits (Mallick, 1993;

Chakrabarti et al., 2002; CFC-Polymer Composites Conference Proceedings, 2002 and 2007).

In the last decade, significant efforts have been made to develop and implement design guidelines,

construction and maintenance standards, and specifications for FRP rebars, wraps, and shapes (I-

section, WF section, box section, angles etc.) including standardized test methods. Various

researchers and organizations have been contributing to cover a wide variety of applications. Large

volume usage of FRPs in civil infrastructure is drawing increased interest including field evaluation

and development of design and construction specifications. The construction of experimental and

demonstration structures using FRP composites in addition to the recent advances in guide

specifications has revealed the potential increase in structural efficiency and economic viability using

FRP components and systems (See list of references in addition to Appendixes B and C, and ASCE

LRFD draft code for FRP, 2010). In addition to providing a greater understanding on the FRP

composite design, optimization, reliability and manufacturing feasibility, the research and

development efforts have been resulting in extensive field implementations and an opportunity to

collect field data to develop better design and construction guidelines.

Advantages and Disadvantages of FRP

In addition to superior thermo-mechanical properties, FRP composites have many advantages over

conventional materials (Tables 1.1 and 1.2). These advantages are gradually being utilized in the

construction industry for infrastructure applications. Some of the marine and water way applications

such as miter gates will greatly benefit by the use of FRPs in terms of high strength, stiffness,

corrosion resistance, ease of installation, simple repair methods, excellent durability, long service

life, minimum maintenance and lower life cycle costs. Some of the advantages of FRPs are:

.

1. Rapid installation: FRPs can be fast implemented due to modular, pre-fabricated, and light

weight units that eliminate forming and curing efforts necessary for conventional materials such

as concrete decks or elaborate welding and riveting needed in heavy steel construction.

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 7 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

2. Light weight: FRP bars are so light weighted as compared to steel which can be transported in

a truck with more number of quantity. A typical 8" FRP deck including wearing surface weighs

25 psf vs. 120 psf for a standard 9.5" concrete deck. Reduction in dead load results in an increased

live load capacity with possible elimination of weight restrictions

3. Reduced interruption: Low down-time of an in-service structure by employing rapid

installation procedures can lead to lower user costs, lower maintenance, higher safety, and better

public relations.

4. Good durability: Excellent resistance to deicing salts and other chemicals results in eliminating

corrosion, cracking, and spalling associated with steel reinforced concrete.

5. Long service life: Large, non-civil FRP structures have performed extremely well in harsh

environments for decades. As an example, FRP bridge decks are expected to provide service life

of about 75-100 years with little maintenance.

6. Fatigue and impact resistance: FRPs have high fatigue endurance and impact resistance.

7. Quality control: Shop fabrication of FRP results in excellent quality control with lower

transportation cost.

8. Ease of installation: FRP structural systems or subsystems such as bridge decks have been used

by general contractors or maintenance crew using standard details with installation time reduction

of up to 80%, thus eliminating traffic congestion and construction site related accident.

9. Cost savings: structural rehabilitation using FRP costs a fraction (1/15th to 1/10th) of the

replacement cost and extends the service life by additional 25-30 years. Rehabilitation also results

in less environmental impact and green house gas emissions (Ryszard, 2010). Similarly, new FRP

construction provides superior FRP thermo-mechanical properties and lower life-cycle costs.

Some of the disadvantages of FRPs are: slightly higher initial costs, limited experience with these

materials by design professionals and contractors, lack of data on long-term field performance, and

absence of full spectrum of codes and specifications similar to conventional materials.

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 8 | P a g e

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Table 1.1 Merit Comparison and Ratings for FRP and Steel Property (Parameter) Merit/Advantage (Rating) Rating Scale

FRP Steel

Strength/stiffness 4-5 4 1: Very Low

2: Low

3: Medium

4: High

5: Very High

Weight 5 2

Corrosion resistance/

Environmental Durability

4-5 3

Ease of field construction 5 3-4

Ease of repair 4-5 3-5

Fire 3-5 4

Transportation/handling 5 3

Toughness 4 4

Acceptance 2-3 5

Maintenance 5 3

Note: Higher rating indicates better desirability of the property

Table 1.2 FRP Merits and Suitability of Applications Parameter FRP Application

FRP Application

Strength/stiffness Very high aerospace

High marine, construction, pipes, bridges, reinforcing bars, automotive

Weight Very high aerospace, marine, construction, pipes, bridges, reinforcing bars, automotive

Corrosion resistance/

Environmental Durability

Very high marine, boat industry, construction industry, aerospace

High automotive, leisurely applications

Ease of field construction High buildings, bridges, pavements, kiln linings, wind mill blades, radomes

Ease of repair High Bridges, tunnels, underwater piles.

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 9 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

Fire Very high aerospace, marine, automotive, blast resistant FRP construction.

Medium bridge decks, leisure products, marine boats

Transportation/handling Very high shapes, bridge decks, components and assembled

FRP systems

Toughness and impact High bullet proof vests, vandalism and graffiti proof walls.

Acceptance low construction and aerospace industries

Low offshore and fire resistant applications.

Some of the marine applications with FRP use are discussed in Chapter 3. Suitability of FRP usage for

offshore and marine applications is listed in Table 1.3.

Table 1.3 FRP Use and Suitability for Marine Applications

Marine/ off-shore

Application FRP Suitability

Advantages Examples

Boating/sports related

moisture resistance, ease of use and repair, high strength/ stiffness, light weight, corrosion resistance

boats, seating and storage compartments, fishing rods etc.

Naval applications

high strength/stiffness, light weight, corrosion resistance, ease of navigation, longer service life

ship decks, aircraft landing platforms, cabins, gun housings, walking platforms, rails etc.

Off-shore applications

moisture resistance, ease of use, high strength/stiffness, corrosion resistance, ease of construction, longer service life, minimum maintenance, ease of repair, fire resistance.

piles, retaining walls, pedestrian walkways, bridges, pavement panels for oil fields and off-shore structures, buoys and floats etc.

Hydraulic structures and supporting structural elements

moisture resistance, high strength/stiffness, light weight, corrosion resistance, longer service life, minimum maintenance and ease of construction.

hydraulic gates, pumps, pipes, dampers, grating structures, access structures etc.

FRP is non corrosive material which can be used in the building reinforcement which reduce the

damage caused by the corrosion. In this paper we will discuss the areas where we can use FRP in the

structure and its stability in that member and at last Cost analysis will be done when we use FRP as

a reinforcement material in the building or any other structure.

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 10 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

1.2 Need of Study Around the world we are having several upcoming projects near the coast line so the study is

needed to understand the effect on cost when we use FRP in the structure because FRP is a costly

material compare to steel which may or may not increase the structure overall cost.

It will may or may not increase the structure cost because if we use FRP in a structure then we can

avoid the problem that we face in a structure caused due to corrosion which reduce strength of the

structure, foundation loosing plaster from the surface of the reinforced section due to expansion

caused due to rusting as well as in building envelopes.

1.3 Aim The aim of the paper is to give a brief about the FRP Products, There properties and the effect on

cost of a structure if we replace steel with FRP.

1.4 Objectives The objectives of this paper are:-

o To study about FRP Manufacturing and its properties.

o To study about the various applications of FRP.

o To design and analyze a FRP member.

o Finite element analysis of a simple beam using FRP as a reinforcement.

o Role of FRP in the sustainable world.

o To find out the cost benefit of the elements used in a corrosive environment structure which

can be replaced by the FRP.

1.5 Scope of study This study will cover all the forms of FRP that can be used in a building and give a brief about FRP

rebars its properties, design, analysis, uses and the effect on cost of a build during construction as

well as the cost analysis of the structure.

This study will give an idea on the advantage of FRP over steel when we are using FRP in a corrosive

environment like coast line and it will give an initial idea to the designer about the advantage and

disadvantage of FRP over steel

Girish Kumar Singh, SPA/NS/BEM/615 Semester II, BEM, SPA, New Delhi 11 | P a g e

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Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

1.6 Methodology • Initially study about the properties of FRP is needed to start the analysis and go through with

the relevant articles/journals, codes available globally.

• Then find out the cost of each element of a building where we can use FRP and to justify that

we can use FRP in the building.

• Analysis of a member where we can use FRP as reinforcement to justify that we can use FRP

as a Reinforcement material.

• The cost analysis for the building by calculating the total quantity and cost of the building

material according to the present market which can be replaced with FRP product to conduct

the cost benefit analysis of FRP

1.7 Seminar Organization

Chapter 1 – Introduction

This chapter describes the intent of this seminar work by describing about the need for the

study, Aim of the work with emphasis on the objective and Scope of the study along with the

methodology used to achieve them.

Chapter 2- Literature Review

This Chapter describes about the available literature on this topic in the form of Books,

Journals, Seminar works, Codes and Standards, Conference proceedings, Published and

unpublished papers etc to establish a theoretical framework for the study topic, define key

terms, definitions and terminology, identify studies, models, case studies etc supporting the

topic and to identify the research gap in available sources.

Chapter 3- Materials Introduction

This chapter gives an introduction of the FRP product, its manufacture process, properties and

the comparison of FRP material with the steel properties, stability, and conductivity etc.

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Chapter 4 – Code Provision

In this chapter the various code used in the design, experiment and analysis is listed.

Chapter 5 – Manual Design Of FRP Beam

In this chapter manual design problem is explained with all the design procedure as per

ACI440.04r and all the tables and equations references are given which are explained in the code.

The design problem is A simply supported, normal weight concrete beam with fc’ = 27.6 MPa is

needed in a facility to support a machine. The beam is an interior beam. The beam is to be

designed to carry a service load of wLL =5.8 kN/m an a superimposed service load od wSDL =3.0

kN/m over a span of l =3.35m.

Chapter 6 – Analysis of Beam Using FEM

This chapter analysis of FRP reinforced beam is analyzed using Finite Element Analysis the

same section that we design in the previous chapter is analyzed and result of that section are

compared to give a relevant theory about its behavior.

Chapter 7 – Costing

This chapter covers costing of the FRP bars and the areas where we can use the FRP product in

the section and the procedure and area where we can save the cost when we are using FRP as

rebar.

Chapter 8- Summery

In this chapter the summer of full report is described

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Study of Material Properties

Applications of FRP Materials

Design of a FRP Member• Manual Design • FEM Analysis of manual design

Costing and Cost analysis of FRP

Summery

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Chapter 2: Literature Review

1. General In this chapter the literature which are used to carry out this study is explained. In this section

we have some main division which are published, unpublished papers, Codes.

2. Codes & Published Papers

2.1 State-of-the-Art Report on Fiber Reinforced Plastic (FRP) Reinforcement for

Concrete Structures (ACI 440.04r, 2002)

In this code the ACI committee broadly explain about the history, property, and supplier of

the FRP in the different countries as well as they explain about some of the projects where they used

FRP in the construction industries.

Fiber Reinforced Plastic (FRP) products were first used to reinforce concrete structures in the mid

1950s (Rubinsky and Rubinsky 1954; Wines et al. 1966). Today, these FRP products take the form

of bars, cables, 2-D and 3-D grids, sheet materials, plates, etc. FRP products may achieve the same

or better reinforcement objective of commonly used metallic products such as steel reinforcing bars,

prestressing tendons, and bonded plates. Application and product development efforts in FRP

composites are widespread to address the many opportunities for reinforcing concrete members

(Nichols 1988). Some of these efforts are:

• High volume production techniques to reduce manufacturing costs

• Modified construction techniques to better utilize the strength properties of FRP and reduce

construction costs

• Optimization of the combination of fiber and resin matrix to ensure optimum compatibility with

Portland cement

• Other initiatives which are detailed in the subsequent

Chapters of this report The common link among all FRP products described in his report is the use

of continuous fibers glass, aramid, carbon, etc.) Embedded in a resin matrix, the glue that allows the

fibers to work together as a single element. Resins used are thermoset (polyester, vinyl ester, etc.) or

thermoplastic (nylon, polyethylene terephthalate, etc.). FRP composites are differentiated from short

fibers used widely today to reinforce nonstructural cementitious products known as fiber reinforced

concrete (FRC). The production methods of bringing continuous fibers together with the resin matrix

allows the FRP material to be tailored such that optimized reinforcement of the concrete structure is

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achieved. The pultrusion process is one such manufacturing method widely practiced today. It is used

to produce consumer and construction products such as fishing rods, bike flags, shovel handles,

structural shapes, etc. The pultrusion process brings together continuous forms of reinforcements and

combines them with a resin to produce high-fiber volume, directionally oriented FRP products. This,

as well as other manufacturing processes used to produce FRP reinforcement for concrete structures,

is explained in more detail later in the report. The concrete industry's primary interest in FRP

reinforcement is in the fact that it does not ordinarily because durability problems such as those

associated with steel reinforcement corrosion. Depending on the constituents of an FRP composite,

other deterioration phenomena can occur as explained in the report. Concrete members can benefit

from the following features of FRP reinforcement: light weight, high specific strength and modulus,

durability, corrosion resistance, chemical and environmental resistance, electromagnetic

permeability, and impact resistance. Numerous FRP products have been and are being developed

worldwide. Japan and Europe are more advanced than the U.S. in this technology and claim a larger

number of completed field applications because their systematic research and development efforts

started earlier and because their construction industry has taken a leading role in development efforts.

2.2 Serviceability of Concrete Beams Prestressed By fiber Reinforced Plastic

Tendons (By Amr. A Abdelrahman1995)

In this paper they shown that CFRP reinforcement can be successfully used for partial prestressing

of concrete beams. The advantages of using this technique to reduce the cost and to increase the

deformability of the structure and they have also done an experimental work to find out the stability

of the FRP as a reinforcement

2.3 Retrofitting of Existing Bridge Using Externally Bonded FRP Composite

Applications and Challenges (MEDIA)

The repair and rehabilitation of aging and deteriorating of concrete bridges and infrastructure poses

an urgent challenge for the civil engineering community. FRPs can play key roles in meeting these

challenges. FRP composite materials show great potential for integration into the bridge

infrastructure. Despite these beneficial superior properties over the other traditional materials,

widespread application of FRP composites to the bridge infrastructure has been slow and uneven.

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With FRP composites, the Western and neighboring countries are already changing the way they

build and maintain their bridges. Although a large research base is already available about these

materials, only a small portion has resulted in actual applications in bridge infrastructure systems in

India.

However, there are several significant, but not insurmountable, challenges to overcome before

widespread implementation occurs. These challenges include a lack of familiarity with the material

among practicing bridge engineers, the cost of the material, and the lack of a unified effort (especially

from a widely accepted coordinating agency) to move implementation efforts forward. Practicing

civil engineers and even most newly graduated civil engineers typically have very little knowledge

of FRP composite materials. If successful widespread application is to occur, these engineers are the

ones who will apply FRP composite materials to the infrastructure. With the removal of certain

obstacles to implementation, FRP composite materials have a place in the bridge infrastructure.

Quality control is crucial to the successful application of FRP systems. Most FRP strengthening

systems are simple to install. However, improper installation (e.g., not properly mixing epoxy

components or saturating the fibers, misaligning the fibers, etc.) could be avoided with careful

attention.

Even though FRP component costs are higher than traditional materials on a square foot basis,

they may be competitive in terms of lifecycle costs. FRP composite materials may be the most cost-

effective solution for repair, rehabilitation, and construction of portions of the bridge infrastructure

if used intelligently.

2.4 The role of FRP composites in a sustainable world (Jain, 2009) The ideal sustainable structure and material would have a closed life cycle where renewable

resources, energy, and zero waste, along with minimal impact on environment and society, are

considered. Certainly, there are few materials that could qualify as ideal sustainable materials and

still satisfy all the performance requirements of structural systems. Even more challenging are the

demands of sustainable design which essentially seeks to achieve tailored design, construction, and

maintenance plans depending on impact priorities, regional issues, and economic requirements.

In the case of FRP composites, environmental concerns appear to be a barrier to its feasibility as a

sustainable material especially when considering fossil fuel depletion, air pollution, smog, and

acidification associated with its production. In addition, the ability to recycle FRP composites is

limited and, unlike steel and timber, structural components cannot easily be reused to perform a

similar function in another structure. On the other hand, FRP composites’ potential benefits, as

described in the paper, may potentially mitigate some environmental impacts

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2.5 Bridge decks of fibre reinforced polymer (FRP): A sustainable solution (Valbona Mara, 2013)

Fibre reinforced polymer (FRP) bridge decks have become an interesting alternative and they have

attracted increasing attention for applications in the refurbishment of existing bridges and the

construction of new bridges. The benefits brought by lightweight, high-strength FRP materials to

these applications are well recognized. However, the sustainability of bridge concepts incorporating

FRP decks still needs to be demonstrated and verified. The aim of this paper is to bridge this

knowledge gap by examining the sustainability of these FRP solutions in comparison with traditional

bridge concepts. An existing composite (steel–concrete) bridge with a concrete deck that had

deteriorated was selected for this purpose. Two scenarios are studied and analyzed the total

replacement of the entire bridge superstructure and the replacement of the concrete deck with a new

deck made of GFRP. The analyses prove that FRP decks contribute to potential cost savings over the

life cycle of bridges and a reduced environmental impact.

2.6 Guide for the Design and Construction of Externally Bonded FRP Systems for

Strengthening Concrete Structures (440, Guide for the Design and Construction of

Externally Bonded FRP Systems for Strengthening Concrete Structures, 2008)

The strengthening or retrofitting of existing concrete structures to resist higher design loads, correct

strength loss due to deterioration, correct design or construction deficiencies, or increase ductility

has traditionally been accomplished using conventional materials and construction techniq ues.

Externally bonded steel plates, steel or concrete jackets, and external post-tensioning are just some

of the many traditional techniques available.

Composite materials made of fibers in a polymeric resin, also known as fiber-reinforced polymers

(FRPs), have emerged as an alternative to traditional materials for repair and rehabilitation. For the

purposes of this document, an FRP system is defined as the fibers and resins used to create the

composite laminate, all applicable resins used to bond it to the concrete substrate, and all applied

coatings used to protect the constituent materials. Coatings used exclusively for aesthetic reasons are

not considered part of an FRP system.

FRP materials are lightweight, noncorrosive, and exhibit high tensile strength. These materials are

readily available in several forms, ranging from factory-made laminates to dry fiber sheets that can

be wrapped to conform to the geometry of a structure before adding the polymer resin. The relatively

thin profiles of cured FRP systems are often desirable in applications where aesthetics or access is a

concern.

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The growing interest in FRP systems for strengthening and retrofitting can be attributed to many

factors. Although the fibers and resins used in FRP systems are relatively expensive compared with

traditional strengthening materials such as concrete and steel, labor and equipment costs to install

FRP systems are often lower (Nanni 1999). FRP systems can also be used in areas with limited access

where traditional techniques would be difficult to implement.

The basis for this document is the knowledge gained from a comprehensive review of experimental

research, analytical work, and field applications of FRP strengthening systems. Areas where further

research is needed are highlighted in this document.

2.7 Guide for the Design and Construction of Structural Concrete Reinforced with FRP

Bars (ACI 440, 2006) This document provides recommendations for the design and construction of FRP reinforced

concrete structures. The document only addresses non prestressed FRP reinforcement (concrete

structures prestressed with FRP tendons are covered in ACI 440.4R). The basis for this document is

the knowledge gained from worldwide experimental research, analytical research work, and field

applications of FRP

Reinforcement. The recommendations in this document are intended to be conservative. Design

recommendations are based on the current knowledge and intended to supplement existing codes and

guidelines for conventionally reinforced concrete structures and to provide engineers and building

officials with assistance in the specification, design, and construction of structural concrete

reinforced with FRP bars. ACI 440.3R provides a comprehensive list of test methods and material

specifications to support design and construction guidelines. The use of FRP reinforcement in

combination with steel reinforcement for structural concrete is not addressed in this document.

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Chapter : 3 Materials Introduction (FRP)

Fibre Reinforced Plastic (FRP) is a composite material made of a polymer matrix reinforced with

fibres. The fibres are usually glass, carbon, aramid, or basalt. Rarely other fibres such as paper or

wood or asbestos have been used. The polymer is usually made up of some organic compound like

an epoxy vinylester or polyester thermosetting plastic and phenol formaldehyde resins are still in use.

There are three type of Fibe Reinforced Plastic:-

• Carbon Fibe Reinforced Plastic

• Glass Fibe Reinforced Plastic

• Aramid Fibe Reinforced Plastic

FRPs are commonly used in the aerospace, automotive, marine, construction industries and ballistic

armor.

3.1 History

Bakelite was the first fibre-reinforced plastic. Dr. Baekeland had originally set out to find a

replacement for shellac (made from the excretion of lac beetles). Chemists had begun to recognize

that many natural resins and fibres were polymers, and Baekeland investigated the reactions of phenol

and formaldehyde. He first produced a soluble phenol-formaldehyde shellac called "Novolak" that

never became a market success, then turned to developing a binder for asbestos which, at that time,

was moulded with rubber. By controlling the pressure and temperature applied

to phenol and formaldehyde, he found in 1905 he could produce his dreamed-of hard mouldable

material (the world's first synthetic plastic): bakelite (Amato, 1999) (Baekeland, 2000)He announced

his invention at a meeting of the American Chemical Society on February 5, 1909 (New Chemical

Substance, 1909).

The development of fibre-reinforced plastic for commercial use was being extensively researched in

the 1930s. In the UK, considerable research was undertaken by pioneers such as Norman de Bruyne.

It was particularly of interest to the aviation industry. (Synthetic Resin – Use in Aircraft Construction,

1936)

Mass production of glass strands was discovered in 1932 when Games Slayter, a researcher at Owens-

Illinois accidentally directed a jet of compressed air at a stream of molten glass and produced fibres.

A patent for this method of producing glass wool was first applied for in 1933 (US Patent Number

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2133235: Method & Apparatus for Making Glass Wool, 1933). Owens joined with the Corning

company in 1935 and the method was adapted by Owens Corning to produce its patented "fibreglas"

(one "s") in 1936. Originally, fiberglass was a glass wool with fibres entrapping a great deal of gas,

making it useful as an insulator, especially at high temperatures.

A suitable resin for combining the "fiberglass" with a plastic to produce a composite material, was

developed in 1936 by du Pont. The first ancestor of modern polyester resins is Cyanamid's resin of

1942. Peroxide curing systems were used by then. (50 years of reinforced plastic boats, 2660) With

the combination of Fiberglas and resin the gas content of the material was replaced by plastic. This

reduced to insulation properties to values typical of the plastic, but now for the first time the

composite showed great strength and promise as a structural and building material. Confusingly,

many glass fiber composites continued to be called "fiberglass" (as a generic name) and the name

was also used for the low-density glass wool product containing gas instead of plastic.

Ray Greene of Owens Corning is credited with producing the first composite boat in 1937, but did

not proceed further at the time due to the brittle nature of the plastic used. In 1939 Russia was reported

to have constructed a passenger boat of plastic materials, and the United States a fuselage and wings

of an aircraft. (Notable Progress – the use of plastics, Evening Post, Wellington, New Zealand,

Volume CXXVIII, Issue 31, 1939) The first car to have a fibre-glass body was the 1946 Stout Scarab.

Only one of this model was built. ( Car of the future in plastics, The Mercury (Hobart, Tasmania),

1946)

The first fibre-reinforced plastic plane fuselage was used on a modified Vultee BT-13A designated

the XBT-16 based at Wright Field in late 1942 (American Warplanes of World War II, David Donald,

Aerospace Publishing Limited, 1995). In 1943 further experiments were undertaken building

structural aircraft parts from composite materials resulting in the first plane, a Vultee BT-15, with a

GFRP fuselage, designated the XBT-19, being flown in 1944. (Conrardy, 1971) (Moulded glass fibre

Sandwich Fuselages for BT-15 Airplane, Army Air Force Technical Report 5159,, 1944)

(Placeholder1) (Reinforced plastics handbook, 2004)A significant development in the tooling for

GFRP components had been made by Republic Aviation Corporation in 1943 (Tim Palucka and

Bernadette Bensaude-Vincent, n.d.) .

Carbon fibre production began in the late 1950s and was used, though not widely, in British industry

beginning in the early 1960s. Aramid fibres were being produced around this time also, appearing

first under the trade name Nomex by DuPont. Today, each of these fibres is used widely in industry

for any applications that require plastics with specific strength or elastic qualities. Glass fibres are

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the most common across all industries, although carbon-fibre and carbon-fibre-aramid composites

are widely found in aerospace, automotive and sporting good applications (Erhard). These three

(glass, carbon, and aramid) continue to be the important categories of fibre used in FRP.

Global polymer production on the scale present today began in the mid 20th century, when low

material and productions costs, new production technologies and new product categories combined

to make polymer production economical. The industry finally matured in the late 1970s when world

polymer production surpassed that of Steel, making polymers the ubiquitous material that it is today.

Fibre-reinforced plastics have been a significant aspect of this industry from the beginning.

3.2 Manufacture Process 3.2.1 General

A polymer is generally manufactured by Step-growth polymerization or addition

polymerization. When combined with various agents to enhance or in any way alter the material

properties of polymers the result is referred to as a plastic. Composite plastics refer to those types of

plastics that result from bonding two or more homogeneous materials with different material

properties to derive a final product with certain desired material and mechanical properties. Fibre-

reinforced plastics are a category of composite plastics that specifically use fibre materials to

mechanically enhance the strength and elasticity of plastics. The original plastic material without

fibre reinforcement is known as the matrix. The matrix is a tough but relatively weak plastic that is

reinforced by stronger stiffer reinforcing filaments or fibres. The extent that strength and elasticity

are enhanced in a fibre-reinforced plastic depends on the mechanical properties of both the fibre and

matrix, their volume relative to one another, and the fibre length and orientation within the matrix

(Smallman). Reinforcement of the matrix occurs by definition when the FRP material exhibits

increased strength or elasticity relative to the strength and elasticity of the matrix alone (Erhard).

Figure 1 Formation Process Of FRP

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3.2.2 Manufacturing Process

FRP involves two distinct processes, the first is the process whereby the fibrous material is

manufactured and formed, the second is the process whereby fibrous materials are bonded with the

matrix during moulding. (Erhard). Chemical Structure is shown in fig. 2

Figure 2 Structure of FRP

3.2.3 Fibre

Reinforcing Fibre is manufactured in both two-dimensional and three-dimensional orientations

1. Two Dimensional Fibre-Reinforced Polymer are characterized by a laminated structure in

which the fibres are only aligned along the plane in x-direction and y-direction of the

material. This means that no fibres are aligned in the through thickness or the z-direction,

this lack of alignment in the through thickness can create a disadvantage in cost and

processing. Costs and labour increase because conventional processing techniques used to

fabricate composites, such as wet hand lay-up, autoclave and resin transfer moulding, require

a high amount of skilled labor to cut, stack and consolidate into a preformed component.

Phenol Formaldehyde

Vinyl Ester

Epoxy

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2. Three-dimensional Fibre-Reinforced Polymer composites are materials with three

dimensional fibre structures that incorporate fibres in the x-direction, y-direction and z-

direction. The development of three-dimensional orientations arose from industry's need to

reduce fabrication costs, to increase through-thickness mechanical properties, and to improve

impact damage tolerance; all were problems associated with two dimensional fibre-

reinforced polymers.

The manufacture of fibre preforms

Fibre preforms are how the fibres are manufactured before being bonded to the matrix. Fibre preforms

are often manufactured in sheets, continuous mats, or as continuous filaments for spray applications.

The four major ways to manufacture the fibre preform is through the textile processing techniques

of Weaving, knitting, braiding and stitching.

1. Weaving can be done in a conventional manner to produce two-dimensional fibres as well in

a multilayer weaving that can create three-dimensional fibres. However, multilayer weaving

is required to have multiple layers of warp yarns to create fibres in the z- direction creating

a few disadvantages in manufacturing, namely the time to set up all the warp yarns on

the loom. Therefore most multilayer weaving is currently used to produce relatively narrow

width products, or high value products where the cost of the preform production is

acceptable. Another one of the main problems facing the use of multilayer woven fabrics is

the difficulty in producing a fabric that contains fibres oriented with angles other than 0" and

90" to each other respectively.

2. The second major way of manufacturing fibre preforms is Braiding. Braiding is suited to the

manufacture of narrow width flat or tubular fabric and is not as capable as weaving in the

production of large volumes of wide fabrics. Braiding is done over top of mandrels that vary

in cross-sectional shape or dimension along their length. Braiding is limited to objects about

a brick in size. Unlike standard weaving, braiding can produce fabric that contains fibres at

45 degrees angles to one another. Braiding three-dimensional fibres can be done using four

step, two-step or Multilayer Interlock Braiding. Four step or row and column braiding utilizes

a flatbed containing rows and columns of yarn carriers that form the shape of the desired

preform. Additional carriers are added to the outside of the array, the precise location and

quantity of which depends upon the exact preform shape and structure required. There are

four separate sequences of row and column motion, which act to interlock the yarns and

produce the braided preform. The yarns are mechanically forced into the structure between

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each step to consolidate the structure in a similar process to the use of a reed in weaving.

Two-step braiding is unlike the four-step process because the two-step includes a large

number of yarns fixed in the axial direction and a fewer number of braiding yarns. The

process consists of two steps in which the braiding carriers move completely through the

structure between the axial carriers. This relatively simple sequence of motions is capable of

forming preforms of essentially any shape, including circular and hollow shapes. Unlike the

four-step process, the two-step process does not require mechanical compaction the motions

involved in the process allows the braid to be pulled tight by yarn tension alone. The last type

of braiding is multi-layer interlocking braiding that consists of a number of standard circular

braiders being joined together to form a cylindrical braiding frame. This frame has a number

of parallel braiding tracks around the circumference of the cylinder but the mechanism allows

the transfer of yarn carriers between adjacent tracks forming a multilayer braided fabric with

yarns interlocking to adjacent layers. The multilayer interlock braid differs from both the

four step and two-step braids in that the interlocking yarns are primarily in the plane of the

structure and thus do not significantly reduce the in-plane properties of the preform. The

four-step and two-step processes produce a greater degree of interlinking as the braiding

yarns travel through the thickness of the preform, but therefore contribute less to the in-plane

performance of the preform. A disadvantage of the multilayer interlock equipment is that due

to the conventional sinusoidal movement of the yarn carriers to form the preform, the

equipment is not able to have the density of yarn carriers that is possible with the two step

and four step machines.

3. Knitting fibre preforms can be done with the traditional methods of Warp and [Weft] Knitting,

and the fabric produced is often regarded by many as two-dimensional fabric, but machines

with two or more needle beds are capable of producing multilayer fabrics with yams that

traverse between the layers. Developments in electronic controls for needle selection and knit

loop transfer, and in the sophisticated mechanisms that allow specific areas of the fabric to

be held and their movement controlled. This has allowed the fabric to form itself into the

required three-dimensional preform shape with a minimum of material wastage.

4. Stitching is arguably the simplest of the four main textile manufacturing techniques and one

that can be performed with the smallest investment in specialized machinery. Basically

stitching consists of inserting a needle, carrying the stitch thread, through a stack of fabric

layers to form a 3D structure. The advantages of stitching are that it is possible to stitch both

dry and prepreg fabric, although the tackiness of the prepreg makes the process difficult and

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generally creates more damage within the prepreg material than in the dry fabric. Stitching

also utilizes the standard two-dimensional fabrics that are commonly in use within the

composite industry therefore there is a sense of familiarity concerning the material systems.

The use of standard fabric also allows a greater degree of flexibility in the fabric lay-up of

the component than is possible with the other textile processes, which have restrictions on

the fibre orientations that can be produced (Tong, 2002)

3.2.4 Forming processes

A rigid structure is usually used to establish the shape of FRP components. Parts can be laid up on a

flat surface referred to as a "caul plate" or on a cylindrical structure referred to as a "mandrel".

However most fibre-reinforced plastic parts are created with a mold or "tool." Molds can be concave

female molds, male molds, or the mold can completely enclose the part with a top and bottom mold.

The moulding processes of FRP plastics begins by placing the fibre preform on or in the mold. The

fibre preform can be dry fibre, or fibre that already contains a measured amount of resin called

"prepreg". Dry fibres are "wetted" with resin either by hand or the resin is injected into a closed mold.

The part is then cured, leaving the matrix and fibres in the shape created by the mold. Heat and/or

pressure are sometimes used to cure the resin and improve the quality of the final part. The different

methods of forming are listed below.

3.2.4.1 Bladder moulding

Individual sheets of prepreg material are laid up and placed in a female-style mould along with a

balloon-like bladder. The mould is closed and placed in a heated press. Finally, the bladder is

pressurized forcing the layers of material against the mould walls.

3.2.4.2 Compression moulding

When the raw material (plastic block,rubber block, plastic sheet, or granules) contains reinforcing

fibres, a compression molded part qualifies as a fibre-reinforced plastic. More typically the plastic

preform used in compression molding does not contain reinforcing fibres. In compression molding,

A "preform" or "charge", of SMC, BMC is placed into mould cavity. The mould is closed and the

material is formed & cured inside by pressure and heat. Compression moulding offers excellent

detailing for geometric shapes ranging from pattern and relief detailing to complex curves and

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creative forms, to precision engineering all within a maximum curing time of 20 minutes (Composite

moulding , 2004).

3.2.4.3 Autoclave / vacuum bag

Individual sheets of prepreg material are laid-up and placed in an open mold. The material is covered

with release film, bleeder/breather material and a vacuum bag. A vacuum is pulled on part and the

entire mould is placed into an autoclave (heated pressure vessel). The part is cured with a continuous

vacuum to extract entrapped gasses from laminate.

This is a very common process in the aerospace industry because it affords precise control over

moulding due to a long, slow cure cycle that is anywhere from one to several hours (Dogan, Donchev,

& Bhonge, 2012).

This precise control creates the exact laminate geometric forms needed to ensure strength and safety

in the aerospace industry, but it is also slow and labour-intensive, meaning costs often confine it to

the aerospace industry (Composite moulding , 2004).

3.2.4.4 Mandrel wrapping

Sheets of prepreg material are wrapped around a steel or aluminium mandrel. The prepreg material

is compacted by nylon or polypropylene cello tape. Parts are typically batch cured by vacuum

bagging and hanging in an oven. After cure the cello and mandrel are removed leaving a hollow

carbon tube. This process creates strong and robust hollow carbon tubes.

3.2.4.5 Wet layup

Wet layup forming combines fibre reinforcement and the matrix as they are placed on the forming

tool (Erhard).]Reinforcing Fibre layers are placed in an open mould and then saturated with a wet

[resin] by pouring it over the fabric and working it into the fabric. The mould is then left so that the

resin will cure, usually at room temperature, though heat is sometimes used to ensure a proper cure.

Sometimes a vacuum bag is used to compress a wet layup. Glass fibres are most commonly used for

this process, the results are widely known as fibreglass, and is used to make common products like

skis, canoes, kayaks and surf boards (Composite moulding , 2004).

3.2.4.6 Chopper gun

Continuous strands of fibreglass are pushed through a hand-held gun that both chops the strands and

combines them with a catalysed resin such as polyester. The impregnated chopped glass is shot onto

the mould surface in whatever thickness the design and human operator think is appropriate. This

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process is good for large production runs at economical cost, but produces geometric shapes with

less strength than other moulding processes and has poor dimensional tolerance (Composite

moulding , 2004).

3.2.4.7 Filament winding

Machines pull fibre bundles through a wet bath of resin and wound over a rotating steel mandrel in

specific orientations Parts are cured either room temperature or elevated temperatures. Mandrel is

extracted, leaving a final geometric shape but can be left in some cases (Composite moulding , 2004).

3.2.4.8 Pultrusion

Fibre bundles and slit fabrics are pulled through a wet bath of resin and formed into the rough part

shape. Saturated material is extruded from a heated closed die curing while being continuously pulled

through die. Some of the end products of pultrusion are structural shapes, i.e. I beam, angle, channel

and flat sheet. These materials can be used to create all sorts of fibreglass structures such as ladders,

platforms, handrail systems tank, pipe and pump supports (Composite moulding , 2004).

3.2.4.9 Resin transfer molding

Also called resin infusion. Fabrics are placed into a mould which wet resin is then injected into.

Resin is typically pressurized and forced into a cavity which is under vacuum in resin transfer

molding. Resin is entirely pulled into cavity under vacuum in vacuum-assisted resin transfer molding.

This moulding process allows precise tolerances and detailed shaping but can sometimes fail to fully

saturate the fabric leading to weak spots in the final shape (Composite moulding , 2004).

3.3 Advantages and limitations

FRP allows the alignment of the glass fibres of thermoplastics to suit specific design programs.

Specifying the orientation of reinforcing fibres can increase the strength and resistance to

deformation of the polymer. Glass reinforced polymers are strongest and most resistive to deforming

forces when the polymers fibres are parallel to the force being exerted, and are weakest when the

fibres are perpendicular. Thus this ability is at once both an advantage and a limitation depending on

the context of use.

Weak spots of perpendicular fibres can be used for natural hinges and connections, but can also lead

to material failure when production processes fail to properly orient the fibres parallel to expected

forces. When forces are exerted perpendicular to the orientation of fibres the strength and elasticity

of the polymer is less than the matrix alone. In cast resin components made of glass reinforced

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polymers such as UP and EP, the orientation of fibres can be oriented in two-dimensional and three-

dimensional weaves.

This means that when forces are possibly perpendicular to one orientation, they are parallel to

another orientation; this eliminates the potential for weak spots in the polymer.

3.4 Failure Mode

Structural failure can occur in FRP materials when:

• Tensile forces stretch the matrix more than the fibres, causing the material to shear at the interface

between matrix and fibres.

• Tensile forces near the end of the fibres exceed the tolerances of the matrix, separating the fibres

from the matrix.

• Tensile forces can also exceed the tolerances of the fibres causing the fibres themselves to

fracture leading to material failure (Erhard).

3.5 Material Requirements

The matrix must also meet certain requirements in order to first be suitable for FRPs and ensure a

successful reinforcement of itself. The matrix must be able to properly saturate, and bond with the

fibres within a suitable curing period. The matrix should preferably bond chemically with the fibre

reinforcement for maximum adhesion. The matrix must also completely envelop the fibres to protect

them from cuts and notches that would reduce their strength, and to transfer forces to the fibres. The

fibres must also be kept separate from each other so that if failure occurs it is localized as much as

possible, and if failure occurs the matrix must also debond from the fibre for similar reasons. Finally

the matrix should be of a plastic that remains chemically and physically stable during and after the

reinforcement and moulding processes. To be suitable as reinforcement material, fibre additives must

increase the tensile strength and modulus of elasticity of the matrix and meet the following

conditions; fibres must exceed critical fibre content; the strength and rigidity of fibres itself must

exceed the strength and rigidity of the matrix alone; and there must be optimum bonding between

fibres and matrix.

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• Glass fibre material

"Fiberglass reinforced plastics" or FRPs (commonly referred to simply as fiberglass) use textile

grade glass fibres. These textile fibres are different from other forms of glass fibres used to

deliberately trap air, for insulating applications (see glass wool). Textile glass fibres begin as varying

combinations of SiO2, Al2O3, B2O3, CaO, or MgO in powder form. These mixtures are then heated

through direct melting to temperatures around 1300 degrees Celsius, after which dies are used to

extrude filaments of glass fibre in diameter ranging from 9 to 17 µm. These filaments are then wound

into larger threads and spun onto bobbins for transportation and further processing. Glass fibre is by

far the most popular means to reinforce plastic and thus enjoys a wealth of production processes,

some of which are applicable to aramid and carbon fibres as well owing to their shared fibrous

qualities.

Roving is a process where filaments are spun into larger diameter threads. These threads are then

commonly used for woven reinforcing glass fabrics and mats, and in spray applications.

Fibre fabrics are web-form fabric reinforcing material that has both warp and weft directions. Fibre

mats are web-form non-woven mats of glass fibres. Mats are manufactured in cut dimensions with

chopped fibres, or in continuous mats using continuous fibres. Chopped fibre glass is used in

processes where lengths of glass threads are cut between 3 and 26 mm, threads are then used in

plastics most commonly intended for moulding processes. Glass fibre short strands are short 0.2–

0.3 mm strands of glass fibres that are used to reinforce thermoplastics most commonly for injection

moulding.

• Carbon fiber

Carbon fibres are created when polyacrylonitrile fibres (PAN), Pitch resins, or Rayon are carbonized

(through oxidation and thermal pyrolysis) at high temperatures. Through further processes of

graphitizing or stretching the fibres strength or elasticity can be enhanced respectively. Carbon fibres

are manufactured in diameters analogous to glass fibres with diameters ranging from 9 to 17 µm.

These fibres wound into larger threads for transportation and further production processes

(Erhard). Further production processes include weaving or braiding into carbon fabrics, cloths and

mats analogous to those described for glass that can then be used in actual reinforcements

(Smallman).

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• Aramid fiber material

Aramid fibres are most commonly known as Kevlar, Nomex and Technora. Aramids are generally

prepared by the reaction between an amine group and a carboxylic acid halide group (aramid)

(Smallman) commonly this occurs when an aromatic polyamide is spun from a liquid concentration

of sulphuric acid into a crystallized fibre (Erhard). Fibres are then spun into larger threads in order

to weave into large ropes or woven fabrics (Aramid) (Smallman). Aramid fibres are manufactured

with varying grades to based on varying qualities for strength and rigidity, so that the material can

be somewhat tailored to specific design needs concerns, such as cutting the tough material during

manufacture (Erhard).

Examples of polymers best suited for the process

Reinforcing Material Most Common Matrix

Materials

Properties Improved

Glass Fibres UP, EP, PA, PC, POM, PP,

PBT, VE

Strength, Elasticity, heat

resistance

Wood Fibres PE, PP, ABS, HDPE, PLA Flexural strength, Tensile

modulus, Tensile Strength

Carbon and Aramid Fibres EP, UP, VE, PA Elasticity, Tensile Strength,

compression strength,

electrical strength.

Inorganic Particulates Semicrystalline

Thermoplastics, UP

Isotropic shrinkage, abrasion,

compression strength

3.6 Material Property

FRP is a composite material so the property of FRP will be very different which are covered below

3.6.1 Corrosion Resistance

FRP/Composites do not rust, corrode or rot, and they resist attack from most industrial and

household chemicals. This quality has been responsible for applications in corrosive environments

such as those found in the chemical processing and water treatment industries. Resistance to

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corrosion provides long life and low maintenance in marine applications from sailboats and

minesweepers to seawalls and offshore oil platforms.

3.6.2 High Strength, Lightweight

FRP/Composites provide high strength to weight ratios exceeding those of aluminum or steel.

High strength, lightweight FRP/Composites are a rational choice whenever weight savings are

desired, such as components for the transportation industry.

3.6.3 Dimensional Stability

FRP/Composites have high dimensional stability under varying physical, environmental, and

thermal stresses. This is one of the most useful properties of FRP/Composites.

3.6.4 Parts Consolidation and Tooling Minimization.

A single FRP composite molding often replaces an assembly of several metal parts and

associated fasteners, reducing assembly and handling time, simplifying inventory, and reducing

manufacturing costs. A single FRP/Composite tool can replace several progressive tools required in

metal stamping.

3.6.5 High Dielectric Strength and Low Moisture Absorption

The excellent electrical insulating properties and low moisture absorption of FRP/Composites

qualify them for use in primary support applications such as circuit breaker housings, and where low

moisture absorption is required.

3.6.6 Minimum Finishing Required

FRP/Composites can be pigmented as part of the mixing operation or coated as part of the

molding process, often eliminating the need for painting. This is particularly cost effective for large

components such as tub/shower units. Also, on critical appearance components, a class “A” surface

is achieved.

3.6.7 Low to Moderate Tooling Costs

Regardless of the molding method selected, tooling for FRP/Composites usually represents a

small part of the product cost. For either large-volume mass-production or limited runs, tooling cost

is normally substantially lower than that of the multiple forming tools required to produce a similar

finished part in metal.

3.6.8 Design Flexibility

No other major material system offers the design flexibility of FRP/Composites. Present

applications vary widely. They range from commercial fishing boat hulls and decks to truck fenders,

from parabolic TV antennas to transit seating, and from outdoor lamp housings to seed hoppers. What

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the future holds depends on the imagination of today’s design engineers as they develop even more

innovative applications for FRP/Composites.

3.6.9 Thermal conductivity

Good insulator with low thermal conductivity. Thermal conductivity 4 (BTU in. /(hr ft2 °F)

Low thermal coefficient of expansion 7 - 8 (in./in./°F) 10-6 . Where steel have Thermal conductivity

260-460 (BTU/sf/hr/°F/in.) Thermal coefficient of expansion 6 - 8 (in./in./°F) 10-6

3.6.10 EMI /RFI Transparency

Not like steel but FRP is Transparent to radio waves and EMI/RFI transmissions.

3.6.11 Physical properties

• Density—FRP bars have a density ranging from 77.8 to 131.3 lb/ft3 (1.25 to 2.1 g/cm3), one-

sixth to one-fourth that of steel (Table 3.1). Reduced weight lowers transportation costs and may

ease handling of the bars on the project site.

Table 3.1—Typical densities of reinforcing bars, lb/ft3 (g/cm3)

Steel GFRP CFRP AFRP 493.00

(7.90)

77.8 to 131.00

(1.25 to 2.10)

93.3 to 100.00

(1.50 to 1.60)

77.80 to 88.10

(1.25 to 1.40)

• Coefficient of thermal expansion—The coefficients of thermal expansion of FRP bars vary

in the longitudinal and transverse directions depending on the types of fiber, resin, and volume

fraction of fiber. The longitudinal coefficient of thermal expansion is dominated by the properties

of the fibers, while the transverse coefficient is dominated by the resin (Bank 1993). Table 3.2 lists the

longitudinal and transverse coefficients of thermal expansion for typical FRP and steel bars. Note that a

negative coefficient of thermal expansion indicates that the material contracts with increased

temperature and expands with decreased temperature. For reference, concrete has a coefficient of

thermal expansion that varies from 4 × 10–6 to 6 × 10–6/°F (7.2 × 10–6 to 10.8 × 10–6/°C) and is

usually assumed to be isotropic (Mindessetal. 2003).

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Table 3.2—Typical coefficients of thermal expansion for reinforcing bars*

Direction CTE, × 10–6/°F (× 10–6/°C)

Steel GFRP CFRP AFRP

Longitudinal, αL 6.5 (11.7) 3.3 to 5.6

(6.0 to 10.0)

–4.0 to 0.0

(–9.0 to 0.0)

–3.3 to –1.1

(–6 to –2)

Transverse, αT 6.5 (11.7) 11.7 to 12.8

(21.0 to 23.0)

41 to 58

(74.0 to 104.0)

33.3 to 44.4

(60.0 to 80.0) *Typical values for fiber volume fraction ranging from 0.5 to 0.7.

3.6.12 Mechanical properties and behavior

• Tensile behavior— When loaded in tension, FRP bars do not exhibit any plastic behavior

(yielding) before rupture. The tensile behavior of FRP bars consisting of one type of fiber material

is characterized by a linearly elastic stress-strain relationship until failure. The tensile properties of

some commonly used FRP bars are summarized in Table 3.3. The tensile strength and stiffness of an FRP

bar are dependent on several factors. Because the fibers in an FRP bar are the main load-carrying

constituent, the ratio of the volume of fiber to the overall volume of the FRP (fiber-volume fraction)

significantly affects the tensile properties of an FRP bar. Strength and stiffness variations will

occur in bars with various fiber-volume fractions, even in bars with the same diameter, appearance,

and constituents.

The rate of curing, the manufacturing process, and the manufacturing quality control also affect the

mechanical characteristics of the bar (Wu 1990). Unlike steel, the unit tensile strength of an FRP bar

can vary with diameter. For example, GFRP bars from three different manufacturers show tensile

strength reductions of up to 40% as the diameter increases proportionally from 0.375 to 0.875 in.

(9.5 to 22.2 mm) (Faza and GangaRao1993b). On the other hand, similar cross section changes do

not seem to affect the strength of twisted CFRP strands (Santoh 1993). The sensitivity of AFRP bars

to cross section size has been shown to vary from one commercial product to rupture strain, εfu (εfu=

εu,ave – 3σ) and a specified tensileanother.

For example, in braided AFRP bars, there is a lessthan 2% strength reduction as bars increase in

diameter from 0.28 to 0.58 in. (7.3 to 14.7 mm) (Tamura 1993). The strength reduction in a

unidirectionally pultruded AFRP bar with added aramid fiber surface wraps is approximately 7% for

diameters increasing from 0.12 to 0.32 in. (3 to 8 mm) (Noritake et al. 1993).

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The FRP bar manufacturer should be contacted for particular strength values of differently sized

FRP bars.

Table 3.3—Usual tensile properties of reinforcing bars

Steel GFRP CFRP AFRP Nominal yield

stress, ksi (MPa)

40 to 75 (276 to

517) N/A N/A N/A

Tensile strength,

ksi (MPa)

70 to 100 (483 to

690)

70 to 230 (483 to

1600)

87 to 535 (600 to

3690)

250 to 368 (1720 to

2540)

Elastic modulus,

×103 ksi (GPa)

29.0 (200.0)

5.1 to 7.4 (35.0 to

51.0) 15.9 to 84.0 (120.0

to 580.0)

6.0 to 18.2 (41.0 to

125.0)

Yield strain, % 0.14 to 0.25 N/A N/A N/A

Rupture strain,

% 6.0 to 12.0 1.2 to 3.1 0.5 to 1.7 1.9 to 4.4

*Typical values for fiber volume fractions ranging from 0.5 to 0.7.

Determination of FRP bar strength by testing is complicated because stress concentrations in and

around anchorage points on the test specimen can lead to premature failure. An adequate testing grip

should allow failure to occur in the middle of the test specimen. Proposed test methods for

determining the tensile strength and stiffness of FRP bars are available in ACI 440.3R.

The tensile properties of a particular FRP bar should be obtained from the bar manufacturer. Usually,

a normal (Gaussian) distribution is assumed to represent the strength of a population of bar specimens

(Kocaoz et al. 2005). Manufacturers should report a guaranteed tensile strength f * , defined by

this guide as the mean tensile strength of a sample of test specimens minus three times the standard

deviation (f * = f – 3σ), and similarly report a guaranteed modulus, Ef (Ef = Ef,ave).

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Figure 3 Stress Strain Curve Fro FRP

These gu a r a n t e ed values of strength and strain provide a 99.87% probability that the

indicated values are exceeded by similar FRP bars, provided that at least 25 specimens are tested

(Dally and Riley 1991; Mutsuyoshietal. 1990). If fewer specimens are tested or a different

distribution is used, texts and manuals on statistical analysis should be consulted to determine the

confidence level of the distribution parameters (MIL-17 1999). In any case, the manufacturer should

provide a description of the method used to obtain the reported tensile properties.

An FRP bar cannot be bent once it has been manufactured (an exception to this would be an FRP

bar with a thermo- plastic resin that could be reshaped with the addition of heat and pressure). FRP

bars, however, can be fabricated with bends. In FRP bars produced with bends, a strength reduction

of 40 to 50% compared with the tensile strength of a straight bar can occur in the bend portion due

to fiber bending and stress concentrations (Nanni et al. 1998).

• Compressive behavior—While it is not recommended to rely on FRP bars to resist

compressive stresses, the following section is presented to fully characterize the behavior of FRP

bars.

Tests on FRP bars with a length-diameter ratio from 1:1 to2:1 have shown that the compressive

strength is lower than the tensile strength (Wu 1990). The mode of failure for FRP bars subjected to

longitudinal compression can include transverse tensile failure, fiber micro buckling, or shear

failure. The mode of failure depends on the type of fiber, the fiber-volume fraction, and the type of

resin. Compressive strengths of 55, 78, and 20% of the tensile strength have been reported for GFRP,

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CFRP, and AFRP, respectively (Mallick 1988; Wu 1990). In general, compressive strengths are

higher for bars with higher tensile strengths, except in the case of AFRP, where the fibers exhibit

nonlinear behavior in compression at a relatively low level of stress.

The compressive modulus of elasticity of FRP reinforcing bars appears to be smaller than its tensile

modulus of elasticity. Test reports on samples containing 55 to 60% volume fraction of continuous E-

glass fibers in a matrix of vinyl ester or isophthalic polyester resin indicate a compressive modulus

of elasticity of 5000 to 7000 ksi (35 to 48 GPa) (Wu 1990).

According to reports, the compressive modulus of elasticity is approximately 80% for GFRP, 85%

for CFRP, and 100% for AFRP of the tensile modulus of elasticity for the same product (Mallick

1988; Ehsani 1993). The slightly lower values of modulus of elasticity in the reports may be attributed

to the premature failure in the test resulting from end brooming and internal fiber micro buckling

under compressive loading.

Standard test methods are not yet established to characterize the compressive behavior of FRP bars. If

the compressive properties of a particular FRP bar are needed, these should be obtained from the bar

manufacturer. The manufacturer should provide a description of the test method used to obtain the

reported compression properties.

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• Shear behavior—Most FRP bar composites are relatively weak in interlaminar shear where

layers of unreinforced resin lie between layers of fibers. Because there is usually no reinforcement across

layers, the interlaminar shear strength is governed by the relatively weak polymer matrix.

Orientation of the fibers in an off-axis direction across the layers of fiber will increase the shear

resistance, depending upon the degree of offset. For FRP bars, this can be accomplished by braiding

or winding fibers transverse to the main fibers. Off-axis fibers can also be placed in the pultrusion

process by introducing a continuous strand mat in the roving/ mat creel.

Standard test methods are not yet established to characterize the shear behavior of FRP bars. If the

shear properties of a particular FRP bar are needed, these should be obtained from the bar

manufacturer. The manufacturer should provide a description of the test method used to obtain the

reported shear values.

• Bond behavior—Bond performance of an FRP bar is dependent on the design, manufacturing

process, mechanical properties of the bar itself, and the environmental conditions (Al Dulaijanetal.

1996; Nannietal. 1997; Bakisetal. 1998b; Banketal. 1998; Freimanisetal. 1998).

When anchoring a reinforcing bar in concrete, the bond force can be transferred by:

• Adhesion resistance of the interface, also known as chemical bond;

• Frictional resistance of the interface against slip and

• Mechanical interlock due to irregularity of the interface.

In FRP bars, it is postulated that bond force is transferred through the resin to the reinforcement

fibers, and a bond- shear failure in the resin is also possible. When a bonded deformed bar is

subjected to increasing tension, the adhesion between the bar and the surrounding concrete breaks

down, and deformations on the surface of the bar cause inclined contact forces between the bar and

the surrounding concrete. The stress at the surface of the bar resulting from the force component in

the direction of the bar can be considered the bond stress between the bar and the concrete.

The bond properties of FRP bars have been extensively investigated by numerous researchers

through different types of tests, such as pullout tests, splice tests, and cantilever beams, to determine an

empirical equation for embedment length (Faza and GangaRao 1990; Ehsani et al. 1996a,b;

Benmokrane 1997; Shield et al. 1999; Mosley 2002; Wambeke and Shield 2006; Tighiouart et al.

1999).

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3.6.13 Time-dependent behavior

• Creep rupture—FRP reinforcing bars subjected to a constant load over time can suddenly

fail after a time period called the endurance time. This phenomenon is known as creep rupture (or

static fatigue). Creep rupture is not an issue with steel bars in reinforced concrete except in extremely

high temperatures, such as those encountered in a fire. As the ratio of the sustained tensile stress to the

short-term strength of the FRP bar increases, endurance time decreases. The creep rupture endurance

time can also irreversibly decrease under sufficiently adverse environmental conditions such as high

temperature, ultraviolet radiation exposure, high alkalinity, wet and dry cycles, or freezing-and-thawing

cycles. Literature on the effects of such environments exists, although the extraction of generalized

design criteria is hindered by a lack of standard creep test methods and reporting and the diversity of

constituents and processes used to make proprietary FRP products. In addition, little data are

currently available for endurance times beyond 100 hours. These factors have resulted in design

criteria judged to be conservative until more research has been done on this subject. Several

representative examples of endurance times for bar and bar- like materials follow. No creep strain

data are available in these cases.

In general, carbon fibers are the least susceptible to creep rupture, whereas aramid fibers are

moderately susceptible, and glass fibers are the most susceptible. A comprehensive series of creep

rupture tests was conducted on 0.25 in. (6 mm) diameter smooth FRP bars reinforced with glass,

aramid, and carbon fibers (Yamaguchi et al. 1997). The bars were tested at different load levels at

room temperature in laboratory conditions using split conical anchors. Results indicated that a linear

relationship exists between creep rupture strength and the logarithm of time for times up to nearly

100 hours. The ratios of stress level at creep rupture to the initial strength of the GFRP, AFRP, and

CFRP bars after 500,000 hours (more than 50 years) were linearly extrapolated to be 0.29, 0.47, and

0.93, respectively.

In another extensive investigation, endurance times were determined for braided AFRP bars and

twisted CFRP bars, both using epoxy resin as the matrix material (Ando et al. 1997). These

commercial bars were tested at room tempera- ture in laboratory conditions and were anchored with

an expansive cementitious grout inside of friction-type grips. Bar diameters ranged from 0.26 to

0.6 in. (5 to 15 mm), but were not found to affect the results. The percentage of stress at creep rupture

versus the initial strength after 50 years calculated using a linear relationship extrapolated from data

available to 100 hours was found to be 79% for CFRP, and 66% for AFRP.

An investigation of creep rupture in GFRP bars in room- temperature laboratory conditions was

reported by Seki et al. (1997). The molded E-glass/vinyl ester bars had a small (0.0068 in.2 [4.4

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mm2]) rectangular cross section and integral GFRP tabs. The percentage of initial tensile strength

retained followed a linear relationship with logarithmic time, reaching a value of 55% at an

extrapolated 50-year endurance time.

Creep rupture data characteristics of a 0.5 in. (12.5 mm) diameter commercial CFRP twisted strand

in an indoor environment is available from the manufacturer (Tokyo Rope 2000). The rupture

strength at a projected 100-year endurance time is reported to be 85% of the initial strength.

An extensive investigation of creep deformation (not rupture) in one commercial AFRP and two

commercial CFRP bars tested to 3000 hours has been reported (Saadatmanesh and Tannous

1999a,b). The bars were tested in laboratory air and in room-temperature solutions with a pH equal

to 3 and 12. The bars had diameters between 0.313 to 0.375 in. (8 to 10 mm), and the applied stress was

fixed at 40% of initial strength. The results indicated a slight trend toward higher creep strain in the

larger-diameter bars and in the bars immersed in the acidic solution. Bars tested in air had the lowest

creep strains of the three environments. Considering all environments and materials, the range of

strains recorded after 3000 hours was 0.002 to 0.037%. Creep strains were slightly higher in the

AFRP bar than in the CFRP bars.

For experimental characterization of creep rupture, the designer can refer to the test method

proposed by a committee of JSCE (1997b), the with the specific title of “Test Method on Tensile

Creep-Rupture of Fiber Reinforced Materials, JSCE-E533-1995.” Creep characteristics of FRP bars

can also be determined from pullout test methods cited in ACI 440.3R. Recommendations on

sustained stress limits imposed to avoid creep rupture are provided in the design section of this guide.

• Fatigue—A substantial amount of data for fatigue behavior and life prediction of stand-

alone FRP materials has been generated in the last 30 years (National Research Council 1991).

During most of this time period, the focus of research investigations was on materials suitable for

aero- space applications. Some general observations on the fatigue behavior of FRP materials can

be made, even though the bulk of the data is obtained from FRP specimens intended for aerospace

applications rather than construction. Unless stated otherwise, the cases that follow are based on

flat, unidirectional coupons with approximately 60% fiber-volume fraction and subjected to tension-

tension sinusoidal cyclic loading at:

• A frequency low enough not to cause self-heating;

• Ambient laboratory environments;

• A stress ratio (ratio of minimum applied stress to maximum applied stress) of 0.1; and

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• A direction parallel to the principal fiber alignment. Test conditions that raise the temperature

and moisture content of FRP materials generally degrade the ambient environment fatigue

behavior.

Of all types of current FRP composites for infrastructure applications, CFRP is generally thought

to be the least prone to fatigue failure. On a plot of stress versus the logarithm of the number of cycles

at failure (S-N curve), the average downward slope of CFRP data is usually about 5 to 8% of initial

static strength per decade of logarithmic life. At 1 million cycles, the fatigue strength is generally

between 50 and 70% of initial static strength and is relatively unaffected by realistic moisture and

temperature exposures of concrete structures unless the resin or fiber/resin interface is substantially

degraded by the environment. Some specific reports of data to 10 million cycles indicated a

continued downward trend of 5 to 8% decade in the S-N curve (Curtis 1989).

Individual glass fibers, such as E-glass and S-glass, are generally not prone to fatigue failure.

Individual glass fibers, however, have demonstrated delayed rupture caused by the stress corrosion

induced by the growth of surface flaws in the presence of even minute quantities of moisture in

ambient laboratory environment tests (Mandell and Meier 1983). When many glass fibers are

embedded into a matrix to form an FRP composite, a cyclic tensile fatigue effect of approximately

10% loss in the initial static capacity per decade of logarithmic lifetime has been observed (Mandell

1982). This fatigue effect is thought to be due to fiber-fiber interactions and not is dependent on the

stress corrosion mechanism described for individual fibers. No clear fatigue limit can usually be

defined. Environmental factors play an important role in the fatigue behavior of glass fibers due to

their susceptibility to moisture, alkaline, and acidic solutions.

Aramid fibers, for which substantial durability data are available, appear to behave similarly to

carbon and glass fibers in fatigue. The tension-tension fatigue behavior of an impregnated aramid

fiber bar is excellent. Strength degradation per decade of logarithmic lifetime is approximately 5 to 6%

(Roylance and Roylance 1981). While no distinct endurance limit is known for AFRP, 2-million-

cycle fatigue strengths of commercial AFRP bars for concrete applications have been reported in

the range of 54 to 73% of initial bar strengths (Odagiri et al. 1997). Based on these findings, Odagiri

et al. suggested that the maximum stress be set at 54 to 73% of the initial tensile strength. Because the

slope of the applied stress versus logarithmic creep-rupture time of AFRP is similar to the slope of

the stress versus logarithmic cyclic lifetime data, the individual fibers appear to fail by a strain-

limited creep-rupture process. This failure condition in commercial AFRP bars was noted to be

accelerated by exposure to moisture and elevated temperature (Roylance and Roylance 1981;

Rostasy 1997).

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Although the influence of moisture on the fatigue behavior of unidirectional FRP materials is

generally thought to be detrimental if the resin or fiber/matrix interface is degraded, research

findings are inconclusive because the performance depends on fiber and matrix types,

preconditioning methods, solution content, and the environmental condition during fatigue (Hayes

et al. 1998; Rahman et al. 1997). In addition, factors such as gripping and presence of concrete

surrounding the bar during the fatigue test need to be considered.

Fatigue strength of CFRP bars encased in concrete has been observed to decrease when the

environmental temperature increases from 68 to 104 °F (20 to 40 °C) (Adimi et al. 1998). In this

same investigation, the endurance limit was found to be inversely proportional to the loading

frequency. It was also found that higher cyclic loading frequencies in the 0.5 to 8 Hz range

corresponded to higher bar temperatures due to sliding friction. Thus, an endurance limit at 1 Hz

could be more than 10 times higher than that at 5 Hz. In the cited investigation, a stress ratio

(minimum stress divided by maximum stress) of 0.1 and a maximum stress of 50% of initial strength

resulted in run outs of greater than 400,000 cycles when the loading frequency was 0.5 Hz. These run

out specimens had no loss of residual tensile strength.

It has been found with CFRP bars that the endurance limit also depends on the mean stress and the

ratio of maximum- to-minimum cyclic stress. Higher mean stress or a lower stress ratio (minimum

divided by maximum) will cause a reduction in the endurance limit (Rahman and Kingsley

1996; Saadatmanesh and Tannous 1999a).

Even though GFRP is weaker than steel in shear, fatigue tests on specimens with unbonded GFRP

dowel bars have shown fatigue behavior similar to that of steel dowel bars for cyclic transverse shear

loading of up to 10 million cycles. The test results and the stiffness calculations have shown that

an equivalent performance can be achieved between FRP and steel bars subjected to transverse shear

by changing some of the parameters, such as diameter, spacing, or both (Porter et al. 1993; Hughes

and Porter 1996).

The addition of ribs, wraps, and other types of deformations improve the bond behavior of FRP bars.

Such deformations, however, have been shown to induce local stress concentrations that significantly

affect the performance of a GFRP bar under fatigue loading situations (Katz 1998). Local stress

concentrations degrade fatigue performance by imposing multiaxial stresses that serve to increase

matrix-dominated damage mechanisms normally suppressed in fiber-dominated composite materials.

Additional fiber-dominated damage mechanisms can be also activated near deformations, depending

on the construction of the bar.

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The effect of fatigue on the bond of deformed GFRP bars embedded in concrete has been

investigated in detail using specialized bond tests (Sippel and Mayer 1996; Bakis et al. 1998a; Katz

2000). Different GFRP materials, environments, and test methods were followed in each cited case,

and the results indicated that bond strength can either increase, decrease, or remain the same following

cyclic loading. Bond fatigue behavior has not been sufficiently investigated to date, and conservative

design criteria based on specific materials and experimental conditions are recommended. Design

limitations on fatigue stress ranges for FRP bars ultimately depend on the manufacturing process of

the FRP bar, environmental conditions, and the type of fatigue load being applied. Given the ongoing

development in the manufacturing process of FRP bars, conservative design criteria should be used

for all commercially available FRP bars.

With regard to the fatigue characteristics of FRP bars, the designer is referred to the provisional

standard test methods cited in ACI 440.3R. The designer should always consult with the bar

manufacturer for fatigue response properties.

• Effects of high temperatures and fire

The use of FRP reinforcement is not recommended for structures in which fire resistance is

essential to maintain structural integrity. Because FRP reinforcement is embedded in concrete, the

reinforcement cannot burn due to a lack of oxygen however, the polymers will soften due to the

excessive heat. The temperature at which a polymer will soften is known as the glass-transition

temperature Tg. Beyond the Tg, the elastic modulus of a polymer is significantly reduced due to

changes in its molecular structure. The value of Tg depends on the type of resin, but is normally

in the region of 150 to 250 °F (65 to 120 °C) (Bootle et al. 2001). In a composite material, the

fibers, which exhibit better thermal properties than the resin, can continue to support some load in

the longitudinal direction; however, the tensile properties of the overall composite are reduced due

to a reduction in force transfer between fibers through bond to the resin. Test results have indicated

that temperatures of 480 °F (250 °C), much higher than the Tg, will reduce the tensile strength of

GFRP and CFRP bars in excess of 20% (Kumahara et al.1993). Other properties more directly

affected by the shear transfer through the resin, such as shear and bending strength, are reduced

significantly at temperatures above the Tg (Wang and Evans 1995). For purposes of design, some

researchers recommended that materials have a Tg at least 54 °F (30 °C) above the maximum expected

temperature (Kollár and Springer et al. 2003).

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For FRP-reinforced concrete, the properties of the polymer at the surface of the bar are essential in

maintaining bond between FRP and concrete. At a temperature close to its Tg, however, the

mechanical properties of the polymer are significantly reduced, and the polymer is not able to transfer

stresses from the concrete to the fibers. One study as the limiting temperature for carbon fibers even

if they might be partially isolated from oxygen by uncracked concrete and charred polymer

(Lamouroux et al. 1999).

Locally, such behavior can result in increased crack widths and deflections. Structural collapse can

be avoided if high temperatures are not experienced at the end regions of FRP bars, allowing

anchorage to be maintained. Structural collapse can occur if all anchorage is lost due to softening of

the polymer or if the temperature rises above the temperature threshold of the fibers themselves. The

latter can occur at temperatures near 1800 ºF (980 ºC) for glass fibers and 350 ºF (175 ºC) for aramid

fibers. Carbon fibers are capable of resisting temperatures in excess of 3000 ºF (1600 ºC). The

behavior and endurance of FRP-reinforced concrete structures under exposure to fire and high heat is

still not well under- stood, and further research in this area is required. ACI 216R may be used for

an estimation of temperatures at various depths of a concrete section.

3.6.14 Chemical Properties

Cured resins (matrix) hold the fibers together for shear transfer. Their chemical resistance against

pH, strength, stiffness, and viscoelastic properties are related to their chemical structure. The

presence of moisture can lead to chemical changes, potentially affecting their properties. FRP

composites employed in marine applications are subjected to hygro-thermal stresses and moisture

induced chemical and mechanical property variations. Water penetrates FRPs through two

processes: diffusion through the resin, and flow through cracks or flaws. During diffusion, absorbed

water is not in the liquid form, but consists of molecules or groups of molecules that are linked

together by hydrogen bonds to the polymer. The molecules dissolved in the surface layer of the

polymer migrate into the bulk of the material under a concentration gradient. Water penetration

into cracks or other flaws occurs by capillary flow. Water also penetrates at the fiber matrix

interface. It is reported that the primary mechanism of moisture pickup is diffusion through resin,

and transfer of moisture through cracks is an after effect. Moisture pickup leads to loss of chemical

energy, which is attributed to hydrolytic scission of ester groups. However, increased hydrostatic

pressure reduces water uptake due to closing of micro cracks. Hence, it is important to maintain

good quality control during manufacturing including complete fiber wet out and high degree of

curing to achieve low void content (preferably less than 0.3%). In addition, proper design may be

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necessary to counter any excessive stresses or stress concentrations induced on structural materials

during fabrication and service.

Diffusion of water into the resin may cause swelling stresses. The equilibrium content of water

determines the magnitude of swelling stresses. The chemical composition of resin influences the

solubility of water in the resin and its susceptibility to hydrolysis. Exposure of composites to moisture

for longer duration results in resin (matrix) plasticization and interface bond strength reduction.

Hence, surfaces of moisture exposed composites are finished with thin layer of gel coat or acrylic

resins to create watertight and water-repellent surfaces.

3.7 Applications Fibre-reinforced plastics are best suited for any design program that demands weight savings,

precision engineering, finite tolerances, and the simplification of parts in both production and

operation. A moulded polymer artefact is cheaper, faster, and easier to manufacture than cast

aluminium or steel artefact, and maintains similar and sometimes better tolerances and material

strengths.

3.7.1 Applications of FRP Composites in Industrial Construction

In the past three decades FRP composites have won an increasing mass fraction of military and civil

applications. Significant investments from private and public funds were made toward research,

development, testing, fabrication and demonstration projects. Confidence in using composite

materials increased dramatically. This was also a period of great innovation in manufacturing,

assembly and repair method development.

The construction industry has also become a major end user of FRP composites due to certain

advantages that will be briefly discussed below. Nowadays the construction industry utilizes FRP

composites based on glass, carbon and aramid fibres embedded in matrices made of polyester, epoxy

and vynilester resins Recently basalt fibres have been introduced especially in application requiring

high temperature exploitation .

The range of properties of FRP composites as well as the formability of FRP composite elements

provides a large variety of load bearing and non structural applications for civil engineering area.

Linear elements, plate and shells elements and folded structures can be easily fabricated and

assembled in different types of buildings or structures.

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Figure 4 FRP Pultruded sections and chemical platform with these products

.

Figure 5 FRP composite tanks: a – horizontal tanks [7]; b – vertical tanks [8]. Fabrication procedures have been specially developed for FRP composite elements and structures;

consequently they have penetrated almost any domain of industrial and agricultural buildings.

Mass production or niche fabrication are currently providing a variety of structural shapes or bars

fabricated by pultrusion and platforms for chemical industry are especially made of these profiles

(Fig. 5). Transport and storage construction elements such as pipes and tanks, are produced using

filament winding (Fig. 5).

Large scale elements with complicated shapes, covering parts for roofs (Figs. 6 and 7), are made

using hand lay-up and/or spray-up.

Figure 6 Large scale GFR polyester dome and skylight.

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Figure 7 Folded skylight on an industrial workshop; double curved shells for an industrial roof.

An application of increasing importance is the use of composites in wind turbine blades (Fig.8 a).

Blades of unusual lengths (up to 125 m) made of a sandwich construction consisting of FRP facings

and light weight foam cores have become familiar in many regions where wind speeds are high and

the wind blows almost continuously. These wind turbines provide a valuable source of clean and

renewable energy.

The offshore platforms have become a new important sector of use for advanced polymer

composites. Particular examples for the application of FRP composites for the offshore construction

include: firewater piping, sea water piping, grating, storage vessels, fire and blast walls (Fig. 8 b).

Recent developments of fibre glass pipes have overcome one of their major drawbacks, namely

leakage [10]. Carbon fibre reinforced polymers (CFRP) composites are utilized not only in

underwater piping but also in structural parts of the platform. On the offshore platform the initial

fears of fire hazard decreased after the research

Figure 8 – a – Blades made of glass fibre reinforced polymer (GFRP) [4]; b – FRP composite components for an offshore platform [6].

work showed that composite laminates thicker than 8 mm perform better than steel in a major fire.

The stairways and walkways are also made of composites for weight saving and corrosion resistance.

Even the cables and ropes made of steel are now being replaced by similar items made of aramid or

high modulus polyethylene fibres.

3.7.2 Application of FRP Composite Systems in Strengthening .

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Strengthening rehabilitation of deteriorated and damaged industrial constructions has become one of

the major issues for civil and industrial engineers all over the world. The main reasons for structural

rehabilitation of the structural elements include: changes in the use of structure and degradation of

the structure. Changes in the use of structure include increased live load or dead load, change in the

load path, new loading requirements and modernization of design practice. Degradation of the

structure comprises: corrosion as a mechanism of structural degradation, fatigue of construction

materials, hazard events, construction errors due to poor construction workmanship or the use of

inferior materials.

FRP composites are recommended for structural rehabilitation solutions because the materials

utilized are light-weight, corrosion resistant and suitable to tailored design. In addition, the FRP

composite products are easily attached to surfaces of elements made of traditional material, require

less labour force and do not modify the dynamic and the seismic characteristics of the load bearing

elements.

A few case studies on the FRP composite application in structural rehabilitation works are presented

in the following.

A comprehensive theoretical and experimental project has been carried out by the authors at the

Faculty of Civil Engineering and Building Services, “Gh. Asachi” Technical University of Iaşi on

the strengthening possibilities with advanced polymeric composites of a complete industrial hall. All

structural members and cladding element have been analysed and the proposed solutions are

illustrated in Fig. 7 .

Industrial chimneys are special industrial structures exploited under severe wind, seismic and

temperature difference conditions.

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Figure 9 Strengthening solutions using FRP based solutions for an industrial hall: a – wall strengthening with

bidirectional strips (1) and unidirectional strips (2); b – column strengthening using discrete strips (3), continuous

wrapping (4) and combined discrete and continuous wrapping (5); c – discrete bending strengthening solutions

for reinforced concrete (RC) girders and continuous membranes (6); d – shear strengthening solutions for RC

girders using bottom flange clamping of inclined strips for runway girders (7) and (8) and U-shaped bands (9); e

– strengthening solution for main transverse girders including end textile clamping (10), plate bonding (11) and

discrete clamping made of composite strips (12); f – plate bonded ribs for roof elements (13).

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Chimneys made of brick and reinforced concrete have been structurally assessed and strengthening

solutions have been proposed.

a b

c d

Figure 10 Composite based strengthening solutions for industrial chimneys: a – wrapping with carbon fibre

balanced fabric; b – confinement with composite hoop strips; c – helicoidal spiral made of composite cable; d –

prefabricated composite membranes [14].

Civil-Inland and Offshore Structural Repairs

FRP composites are ideally suited as quick and effective structural repair tool because of their

lightweight, high strength and corrosion resistance. Bridge repair using FRP composites is a major

success story and many details can be found in the book authored by GangaRao, Taly, and Vijay,

entitled “Reinforced Concrete Design with FRP Composites” (2007). Storage tanks for liquids are

ideal application of FRP using corrosion and solvent resistant resins. FRP tanks are easy to install,

more economical than the conventional materials, and they have better service life. Researchers

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visualize that within a few years large number of tanks, starting from municipal water tanks to large

petrochemical tanks, will be built with FRP composites (Chakrabarti et al., 2002).

The availability of resins that cure under water has extended the FRP wrap application to

substructure elements such as partially submerged piles that are damaged (refer to Chapter 8). Also,

FRP composites have been used in offshore platforms where corrosion in the presence of seawater

is a major concern. Some of the current FRP applications are (Moahmoud et al 2009): i. Low

pressure pipes

ii. Diesel storage tanks, lube tanks, and utility tanks

iii. Walkway gratings, stair steps, and handrails

iv. Cable ladders and trays

v. Fire protection panels and sections of accommodation modules vi. Buoys and floats

vii. Strengthening of primary steel structures

viii. Helicopter landing decks

ix. Walls and floors to provide protection against blast and fire

The higher cost of constructing offshore structures with composites compared with welded steel is

a concern. However, the significant through-life cost savings can be gained with composites due to

reduced maintenance and premature replacement of corroded structures.

3.7.3 Army, Marine, and Related Applications In 2000, the French Water Authority (Voies Navigables de France) introduced a new generation

hybrid lock gate developed by DGA - DCN Lorient, designed for use on small or Freycinet-type

inland waterway networks (locks under 6.5 meters in width with mitre-type gates). The hybrid lock

gate is made of FRP material (two surface laminates of 5.2m wide and up to 8m tall with horizontal

stiffeners) and strengthened with stainless steel frame and its self weight is only 40% of steel

(Advanced Material and Composites News, 2000). Light weight results in easy transportation,

placement, and facilitates hand assembly

Now different types of hybrid FRP gates (12‟x12‟) with steel core are available commercially for

water-flow-control applications including sluice gates, slide gates, stop gates, weir gates and flap

gates. They are reported to be capable of holding water pressure up to 100ft (Plasti-Fab.com).

Submersible pump manufacturers now offer FRP packaged pump stations, for general civil works,

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particularly for sewage and storm water pumping, to take advantage of lightweight, and corrosion

resistance properties of FRP (flygetus.com).

3.7.4 FRP Pipes for Marine Applications

FRP pipes such as those required for marine applications are designed with high safety factors (6

to 12), depending on the loading and application parameters such as stress levels and stress

concentrations, stress (pressure) surges, operating temperatures, water hammer effects etc. FRP

pipes are typically designed on allowable strain basis with due consideration provided to pressure

and temperature such that repeated residual strain accumulation and damage are prevented;

however, FRP structures are typically designed for deflection limit states.

Large FRP pipe systems with diameters up to 13ft and a minimum of 50-year design life are being

manufactured for the following infrastructure applications:

Large potable water transmission pipeline

Slip lining of corroded large concrete sewer pipes and tunnels

Large gravity sewer and storm water drains

Large siphons and culverts

River and seawater intakes and outfalls

Power plant circulating and cooling water lines

Large power plant penstocks

Large irrigation pipelines

Large pump station headers

Figure 11: Very large FRP pipe systems from Future Pipe Industries (www.futurepipe.com)

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3.7.5 FRP Piling

A full-scale feasibility assessment was conducted on different types of FRP composite-bearing

piles at Port Elizabeth, NJ. The study consisted of the following:

Evaluation of equivalent mechanical short-term properties of the composite material

include: elastic modulus for the initial loading quasilinear phase, axial compression

strength, inertia moment, and critical buckling load. These FRP composites consisted of

recycled plastic reinforced by fiberglass rebar (SEAPILE™ composite marine piles),

recycled thermo plastic reinforced by steel bars, and recycled plastic reinforced with

randomly distributed fiberglass (Trimax), manufactured respectively by Seaward

International Inc., Plastic Piling, Inc., and U.S. Plastic Lumber (Juran and Komornik, 2006).

Response analysis of FRP piles under static and dynamic loads.

Feasibility estimate of installing FRP piles using standard pile driving equipment, capacity,

and constructability.

Figure 12 Composite marine piles from different manufacturers were tested. Shown in pictures: SEAPILE, PPI

and Trimax piles, (Juran and Komornik, 2006)

As a result of the study related to FRP piles, Juran and Komornik (2006) concluded that FRP

composite piles could be used as an alternative engineering solution for deep foundations. These

authors recommended further research regarding time-dependent stress-response of composite

recycled plastic material to be done before a wider spread use of these piles. One of the main

concerns was that FRP piles may undergo higher deformations under sustained loads than metals

(Juran and Komornik, 2006). However, creep studies on FRP reinforced concrete members and

FRP shapes have indicate an excellent creep performance of those FRP members when provided

with proper fiber/fabric architecture and fiber volume fraction. Lower stiffness of FRP results in

higher deformation than metals and this disadvantage has to be overcome by designing innovative

shapes with higher moment of inertia (Batra et al., 2009).

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3.7.6 Other FRP applications

FRP manholes (Fig. 13) are commercially available with diameters up to 72 inches. Similarly, aircraft

structures made of composites (Fig. 14) are gaining popularity because of their high strength to

weight ratio.

Figure 13 Composite marine piles from different manufacturers were tested. Shown in pictures: SEAPILE, PPI

and Trimax piles, (Juran and Komornik, 2006)

Figure 14 Boeing 787 Dreamliner, the world's first major commercial airliner to use composite materials for

most of its construction (www.boeing.com)

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3.7.7 FRP Design, Development and Field Implementation by CFC-WVU and Others

Some of the FRP design, development, and field implementation activities carried out by

CFCWVU are shown in Figs. 15 through 2.16. This design, manufacturing, field implementation,

and monitoring work by the CFC-WVU over last two decades has contributed to the development

and publication of design documents, specifications, various short courses, conferences, and

technology transfer activities. Some of the related bridge applications in Switzerland and USA are

also shown in Fig. 16.

Figure 15 FRP Design and Applications by the CFC-WVU, (Top L to R) – i) FRP dowels in highway pavement

(Elkins, WV), ii) FRP reinforcement for concrete highway pavement (Charleston, WV), and iii) FRP

thermoplastic tie for railroads (Moorefield, WV); (bottom L to R) - i) FRP pavement panels (Morgantown, WV,

iii) thermoplastic FRP offset block for guardrails, (Morgantown, WV) (Courtesy: CFC-WVU).

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Figure 16 FRP bridge deck shapes designed and field implemented in WV and Ohio by the CFC-WVU

(Courtesy: CFC-WVU)

Figure 17 FRP application for ship decks L); successful testing of fire resistant FRP panel at 5800 degree F with

acetylene torch for 5 minute at CFC-WVU. (Courtesy: CFC-WVU)

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Figure 18 FRP Inspection Walkway Blennerhassett Bridge, Parkersburg, WV (Courtesy: CFC-WVU)

Figure 19 Examples of FRP application for bridges: (Top L to R)- i) Carbon cables used in bottom chord, Kleine

Emme Bridge, Switzerland (Courtesy: Dr. Urs Meier); ii) FRP pedestrian bridge over 9th Street, NY; (bottom L to R)-

iii) Neal Bridge, Maine with FRP tubes (courtesy: NYTimes.com); iv) Proposed FRP Pedestrian Bridge at West

Virginia University, Morgantown)

3.7.8 Application of FRP as Rebar

FRP is used in many of the project as rebar which give a very high durability to the structure as

well as it is very light in weight so the structure weight also reduce. Majorly FRP is used in the

bridge deck

The material characteristics of FRP reinforcement need to be considered when determining whether

FRP reinforcement is suitable or necessary in a particular structure The corrosion resistance of FRP

reinforcement is a significant benefit for structures in highly corrosive environments such as seawalls

and other marine structures, bridge decks and superstructures exposed to deicing salts, and pavements

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treated with deicing salts. In structures supporting magnetic resonance imaging (MRI) units or other

equipment sensitive to electromagnetic fields, the nonmagnetic properties of FRP reinforcement are

unrivaled. FRP reinforcement has a non-ductile behavior that is partially compensated by its high

tensile strength. The use of FRP reinforcement should be limited to structures that will significantly

benefit from other properties such as the noncorrosive or nonconductive behavior of its materials. Due

to lack of experience in its use, FRP reinforcement is not recommended for moment frames or zones

where moment redistribution is required.

FRP reinforcement should not be relied on to resist compression. Available data indicate that the

compressive modulus of FRP bars is lower than its tensile modulus. Due to the combined effect of

this behavior and the relatively lower modulus of FRP compared with steel, the maximum contribution

of compression FRP reinforcement calculated at crushing of concrete (typically at εcu = 0.003) is small.

Therefore, FRP reinforcement should neither be used as reinforcement in columns nor other in

compression members, nor as compression reinforcement in flexural members. It is acceptable for FRP

tension reinforcement to experience compression due to moment reversals or changes in load pattern.

The compressive strength of the FRP reinforcement should not, however, be neglected. Further

research is needed in this area.

Commercially available FRP reinforcing materials are made of continuous aramid FRP (AFRP),

carbon FRP (CFRP), or GFRP fibers embedded in a resin matrix (ACI 440R). Typical FRP

reinforcement products are grids, bars, fabrics, and ropes. The bars have various types of cross-

sectional shapes (square, round, solid, and hollow) and deformation systems (exterior wound fibers,

sand coatings, and separately formed deformations). A sample of five distinctly different GFRP

reinforcing bars is shown in Fig. 20.

Figure 20 Commercially available GFRP reinforcing bars

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Chapter 4 Code Provision

1.1 Standard test methods for FRP bars and laminates ACI 440, ASTM, CEN (European Committee for Standardization), CSA (Canadian Standards Association),

and JSCE (Japan Society for Civil Engineering) provide guidelines on different test methods. These

guidelines provide details about preparing the samples, conditioning the specimens, test procedures, and

calculations. Some of these are listed in Tables 4.1 It should be noted that these tables do not provide a

complete list and some related aspects and specifications are also listed in appendix C.

Some of the standard test methods available for testing FRP laminates and bars are provided in Tables 4.2

Brief description on these standards is provided in Appendix C. Many of these specifications have been

developed after the publication of ETL 1110-2-548. These specifications are useful for both updating the

information presented in ETL 1110-2-548 and design of FRP structures.

Table 4.1: Available standard test methods for FRP laminates used as strengthening or repair materials

adopted from ACI 440.3R-04

Property Test method Property Test method

Direct tension pull-off ASTM-D4551

ACI 440-L.1

Tensile strength and modulus ASTM-D3039

ACI 440-L.2 Lap shear strength ASTM-D3165

ASTM-D3528

ACI 440-L.3

Bond strength ASTM-D4551

ASTM-DC882

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Table 4.2: Available standard test methods for FRP bars used for reinforcing or prestressing concrete

adopted from ACI 440.3R-04

Property Test method Property Test method

Cross-sectional area ACI 440 –B.1 Longitudal tensile strength and

modulus ASTM-D3916

ACI 440-B.2 Bond properties ASTM-A944

ACI 440-B.3

Shear Strength ASTM-D5379

ASTM-D3846

ASTM-D2344

ASTM-D4475

ACI 440-B.4 Bent bar capacity ACI-B.5 Durability properties ACI 440-B.6 Fatigue properties ASTM-D3479

ACI 440-B.7

Creep properties ASTM D-2990

ACI 440-B.8 Relaxation properties ASTM-D2990

ASTM-E328

ACI 440-B.9

Anchorage properties ACI 440-B.10

Tensile properties of deflected

bars ACI 440-B.11 Effect of corner radius on strength ACI 440-B.12

Flexural properties ASTM-D790

ASTM-D4476

Coefficient of thermal expansion ASTM-E831

ASTM-D696 Glass transition temperature ASTM-E1356

ASTM-E1640

ASTM-D648

ASTM-E2092

Volume fraction ASTM-D3171

ASTM-D2584

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Chapter 5 Manual Design of FRP Beam In this chapter manual design problem is explained with all the design procedure as per ACI440.04r and all the tables and equations references are given which are explained in the code. The design problem is A simply supported, normal weight concrete beam with fc’ = 27.6 MPa is needed in a facility to support a machine. The beam is an interior beam. The beam is to be designed to carry a service load of wLL =5.8 kN/m an a superimposed service load od wSDL =3.0 kN/m over a span of l =3.35m.

Step 1—Estimate the appropriate cross-sectional dimensions of the beam.

An initial value for the depth of a simply supported reinforced concrete beam can be estimated

from Table 8.2.

H = L/10

h = 3.35/10 = 0.335m

Recognizing that the values suggested in the table are meant only to be a starting point for design,

try h = 304mm

Try h = 305mm <335mm

Assuming 16mm dia bars for main

Assuming 9.5mm dia for shear

Cover = 38mm

A minimum width of approx. 178mm is required when using two 16mm or two 19mm bars with

9.5 mm stirrups.

b = 200 mm l = 3.35 m

d = 250 mm

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Try b = 0.178 m

An effective depth of the section is estimated using 1-1/2 in. clear cover

Estimated d = h − cover − db,shear − d/2

d = 305mm-38mm-9.5mm-16mm/2

= 250 mm

Step 2—Compute the factored load.

The uniformly distributed dead load can be computed including the self-weight of the beam.

WDL = WSDL + WSW

= (3kN/m)+(0.178m)(0.305m)(24kN/m3)

= 4.3kN/m

Compute the factored uniform load and ultimate Moment

Wu = 1.2 WDL + 1.7 WLL

= 1.2(4.3kN/m)+1.7(5.8kN/m)

= 14.4 kN/m

Mu = Wul2/8

= ((14.4kN/m)(3.35m)2)/8

= 20.2kNm

Step 3—Compute the design rupture stress of the FRP bars.

The beam will be located in an interior conditioned space. Therefore, for glass FRP bars, an

environmental reduction factor CE of 0.80 is as per Table 7.1.

ffu = CE f*fu

= (0.8)(620.6kN/mm2)

= 496 kN/mm2

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Step 4— Determine the area of GFRP bars required for flexural strength.

Find the reinforcement ratio required for flexural strength by trial and error using Eq. (8-1), (8-4d),

and (8-5).

Assuming an initial amount of FRP reinforcement

Trying for 16mm of bars

Computed the balanced FRP reinforcement ratio

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= (440800N/mm2)(0.003) = 0.0086

(44,800N/mm2)(0.003)+(496N/mm2)

= 400mm2 = 0.009

(178mm)(250 mm)

Where:- ρfb = FRP reinforcement ratio producing balanced

strain conditions

ρf = FRP reinforcement ratio

β1 = F a c t o r taken as 0.85 for concrete strength fc′ up to and including 4000 psi (28 MPa). For strength

above 4000 psi (28 MPa), this factor is reduced continuously at a rate of 0.05 per each 1000 psi (7 MPa) of

strength in excess of 4000 psi (28 MPa), but is not taken less than 0.65

fc′ = Specified Compressive Strength Of Concrete, Psi (Mpa)

ffu = Design Tensile Strength Of FRP, Considering Reductions For Service Environment, Psi (Mpa) Ef = Design Or Guaranteed Modulus Of Elasticity Of FRP Defined As Mean Modulus Of Sample Of Test

Specimens (Ef = Ef,Ave), Psi (Mpa)

εcu = Ultimate Strain In Concrete

Af = Area Of FRP Reinforcement, In.2 (Mm2)

b = Width Of Rectangular Cross Section, In. (Mm)

d = Distance From Extreme Compression Fiber To Centroid Of Tension Reinforcement, In. (Mm)

Where ff = Stress In FRP Reinforcement In Tension, psi (MPa)

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A = ((44,800N/mm2)(0.003))2 = 4516

4

B = 0.85(0.85)(27.6N/mm2)(44,800N/mm2)(0.003) = 297800

0.009

C = 0.5(44,800N/mm2)(0.003) = 67.2

= N/mm2

= 43.9kN.mm

Mn = Nominal Moment Capacity, Lb-In. (N-mm)

Mu= Factored Moment At Section, Lb-In. (N-mm)

= 0.562

ΦMn = 24.7kNm >= Mu =20.2kNm

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Step 5—Check the crack width.

Compute the stress level in the FRP bars under dead load plus live load.

= 6.03kNm

= 8.14kNm

= 6.03+8.14 = 14.17 kNm

= 1.8

= 0.165

= 149.9 N/mm2

Where:-

fc′= specified compressive strength of concrete, psi (MPa)

k = ratio of depth of neutral axis to reinforcement depth

ff= stress in FRP reinforcement in tension, psi (MPa)

Determine the strain gradient used to transform

Determine the strain gradient used to transform reinforcement level strains to the near surface of

the beam where cracking is expected

= 1.263

β = ratio of distance from neutral axis to extreme tension fiber to distance from neutral axis to

center of tensile reinforcement h = overall height of flexural member, in. (mm)

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Calculate the distance from the extreme tension fiber of the concrete to the centerline of the flexural

reinforcement.

dc = h –d = 55mm

Calculate bar spacing s.

s = b – 2dc = 68 mm

Compare the crack width from Eq. (8-9) using the recommended value of kb = 1.4 for deformed

FRP bars.

= 0.77 mm

Note that it is preferable to use bars with smaller diameters to mitigate cracking. For example,

using three φ12.7 bars will result in approximately the same area of FRP and nearly the same

effective depth however, the width of the member would need to be increased.

Crack width limitation controls the design. Try larger amount of FRP reinforcement.

To maintain b= 0.178 mm

Try 2 φ 19 = Af = 567 mm2

= 248 mm

= 0.0128

Calculate the new capacity.

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A = 4156

B = 209,400

C = 672

= 395.3 N/mm2

Mn = 49.4 kNm

P0 =.0128 > 1.4fb = 0.012

ΦMn = 32.1 kN.m >= M0 = 22.3 kNm

= 0.193

= 107.7 N/mm2

= 1.285

Calculate the distance from the extreme tension fiber of the concrete to the centerline of the flexural

reinforcement.

dc = h –d = 57 mm

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Calculate bar spacing s.

= 64 mm

Compare the crack width from Eq. (8-9) to the design limit using the default value of kb = 1.4 for

deformed FRP bars.

= 0.57 mm < 0.7 mm OK

Step 6—Check the long-term deflection of the beam

Compute the gross moment of inertia for the section.

= 4209 X 100 mm4

Ig= Gross moment of inertia

Calculate the cracked section properties and cracking moment.

= 3.26 N/mm2

= 9.00 kN.m

= 4.47 X 107 mm4

Compute the modification factor βd.

= 0.03

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Compute the deflection due to dead load plus live load.

= 6.76 X 100 mm4

= 10 mm

Where:-

Ie= effective moment of inertia

βd = reduction coefficient used in calculating deflection

Ma = maximum moment in member at stage deflection is computed, lb-in. (N-mm)

Δ = Deflection

Compute the deflection due to dead load alone and live load alone.

= 4.3 mm

= 5.7 mm

Compute the multiplier for time-dependent deflection using a ξ = 2.0 (recommended by ACI 318

for a duration of more than 5 years).

λ = 0.60ξ

λ=1.2

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Compute the long-term deflection (initial deflection due to live load plus the time-dependent

deflection due to sustained loads).

= 12.2 mm

Check computed deflection against deflection limitations.

= 12.2 mm < 14mm

Step 7—Check the creep rupture stress limits.

Compute the moment due to all sustained loads (dead load plus 20% of the live load).

= 7.66 kN.m

Ms = moment due to sustained load, lb-in. (N-mm)

Compute the sustained stress level in the FRP bars.

= 58.2n/mm2

Check the stress limits given in Table 8.2 for glass FRP bars.

58.2 N/mm0 <= 0.20(496) = 99.2 N/mm2

ff,s = stress level induced in FRP by sustained loads, psi (MPa) Step 8—Design for shear.

Determine the factored shear demand at a distance d from the support

= 20.6 kN

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Compute the shear contribution of the concrete for an FRP-reinforced member.

= 17.9 kN

FRP shear reinforcement will be required. The FRP shear reinforcement will be assumed to be No.

3 closed stirrups oriented vertically. To determine the amount of FRP shear reinforcement required,

the effective stress level in the FRP shear reinforcement must be determined. This stress level may

be governed by the allowable stress in the stirrup at the location of a bend, which is computed as

follows:

= 223.2 N/mm2

The design stress of FRP stirrup is limited to:

= 179.2 N/mm2<= 223.2 N/mm2

The required spacing of the FRP stirrups can be computed by rearranging Eq. (9-4).

= 660 mm

S<= 248/2 = 124 mm

S<= 600

Check maximum spacing limit = d/2 or 24 in. Equation (9-7) for minimum amount of shear

reinforcement can be rearranged as s ≤ Afv ffv/0.35bw (SI).

According to Afv ffv/0.35bw

S<= 477 mm

Use of 10 stirrups at 120 mm on center

Step 9—Check that the required bar stress can be developed, and that anchorage bond is

sufficient.

Find C = min(cover to the center of the bar, 1/2 c-o-c spacing)

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9 mm c/c 120 mm

C = min (38 mm + 9.5 mm +19/2 .64/2)

C = 32 mm

Determine the bar stress that is developable at midspan for the provided embedment length le = l/2.

395.3N/mm0 > 496 N/mm2 ,so flexural

strength is not limited by bond

Compare developable bar stress ffe with required bar stress for flexural strength ff.

Check anchorage development in positive moment region.

= 70 mm

Check the development of the positive reinforcement at the simply supported end.

= 2025 mm

The development length of the section is 2.025 m from the mid point if the bar which should be

covered inside the section in case of simply supported section.

Results

The ultimate load carrying capacity of the beam is 14.4 kN/m and the moment in the beam is 20.2

kNm, the stress in the reinforcement is 149.9 N/mm2 so we use 2 bars of 19 mm dia. With spacing

of 60 mm c/c and the stirrups will be of 9 mm dia with a spacing of 120 mm c/c and the max.

Deflection is 12.2 mm

50 mm

b = 200 mm l = 3.35 m

d = 250 mm

` 19mm c/c 60 mm

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Chapter 6 Analysis of Beam Using FEM General

To provide a detailed review of the body of literature related to reinforced concrete in its entirety

would be too immense to address in this paper. However, there are many good references that can be

used as a starting point for research (ACI 1978,MacGregor 1992, Nawy 2000). This literature review

and introduction will focus on recent contributions related to FEA and past efforts most closely

related to the needs of the present work.

The use of FEA has been the preferred method to study the behavior of concrete (For economic

reasons). William and Tanabe (2001) contains a collection of papers concerning finite element

analysis of reinforced concrete structures. This collection contains areas of study such as: seismic

behavior of structures, cyclic loading of reinforced concrete columns, shear failure of reinforced

concrete beams, and concrete steel bond models.

Shing and Tanabe (2001) also put together a collection of papers dealing with In-elastic

behavior of reinforced concrete structures under seismic loads. The monograph contains

contributions that outline applications of the finite element method for studying post-peak cyclic

behavior and ductility of reinforced concrete beam, the analysis of reinforced concrete components

in bridge seismic design, the analysis of reinforced concrete beam-column bridge connections, and

the modeling of the shear behavior of reinforced concrete bridge structures.

The focus of these most recent efforts is with bridges, columns, and seismic design. The focus

of this seminar is to study of non-prestressed flexural members.

AMR A. ABDELRAHMAN(1995) give the basic behavior of non- prestressed member with

full experimental data and the specification of the section with its dimension and the number of

strands used in every section during casting. He also provides the property of FRP material used in

the section and the results obtained after the testing of the section.

The following is a review and synthesis of efforts most relevant to this Seminar discussing

FEA applications, experimental testing, and concrete material models.

Finite Element Analysis

Finite element analysis is an effective method of determining the static performance of

structures for the reasons which are saving in design time cost effective in construction and increase

the safety of the structure. Previously it is necessary to use advanced mathematical methods in

analysis large structures, such as bridges tall buildings and other more accuracy generally required

more elaborate techniques and therefore a large friction of the designer’s time could be devoted to

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mathematical analysis. Finite element methods free designer’s from the need to concentrate on

mathematical calculation and allow them to spend more time on accurate representation of

the intended structure and review of the calculated performance (Smith, 1988). Furthermore by using

the programs with interactive graphical facilities it is possible to generate finite element models of

complex structures with considerable ease and to obtain the results in a convenient readily

assimilated form. This may save valuable design time. More accurate analysis of structure is possible

by the finite element method leading to economics in materials and construction also in enhancing

the overall safety (DeSalvo and Swanson, 1985).

However in order to use computer time and design time effectively it is important to plan the

analysis strategy carefully. Before a series of dynamic tests carry out in the field a complete three-

dimensional finite element models are developed for a bridges prior to its testing. The results from

these dynamic analyses are used to select instrument positions on the bridge and predict static

displacement. Then, they are calibrated using the experimental frequencies and mode shapes. The

frequencies and mode shapes mainly are used to provide a basis for the study of the influence of

certain parameters on the dynamic response of the structure the influence of secondary structural

elements the cracking of the deck slabs the effects of long-term concrete creep and shrinkage and

soon (Paultre and Proulx, 1995). Besides more sophisticated methods based on finite element or

finite strip representation have been used by some researchers to study the dynamic behaviour of

bridges Fam (1973) and Tabba(1972) studied the behaviour of curved box section bridges using the

finite element method for applied static and dynamic loads. A three-dimensional finite element

analysis program was developed for curved cellular structures. Solutions of several problems

involving static and dynamic responses were presented using the proposed and others sophisticated

methods of analysis. In this report a beam is analysed using FEM.

Element Used In Member ANSYS 2012

Element which are used in this report are:

Solid 65 For concrete

Link 8 For Rebar

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Finite element model of concrete SOLID65 Description:

SOLID65 is used for the 3-D modeling of solids with or without

reinforcing bars (rebar). The solid is capable of cracking in tension and crushing in

compression. In concrete applications, for example, the solid capability of the element may be

used to model the concrete while the rebar capability is available for modeling reinforcement

behavior. Other cases for which the element is also applicable would be reinforced composites (such

as fiberglass), and geological materials (such as rock). The element is defined by eight nodes having

three degrees of freedom at each node: translations in the nodal x, y, and z directions. Up to three

different rebar specifications may be defined. The concrete element is similar to the SOLID45 (3-D

Structural Solid) element with the addition of special cracking and crushing capabilities. The most

important aspect of this element is the treatment of nonlinear material properties. The concrete is

capable of cracking (in three orthogonal directions), crushing, plastic deformation, and creep. The

rebar are capable of tension and compression, but not shear. They are also capable of plastic

deformation and creep.

Figure 21 Solid 65 Geometry

SOLID65

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Input Summary

Nodes:-I, J, K, L, M, N, O, P

Degrees of Freedom:-UX, UY, UZ

Real Constants:-MAT1, VR1, THETA1, PHI1, MAT2, VR2, THETA2, PHI2, MAT3, VR3,

THETA3, PHI3, CSTIF

(where MAT n is material number, VR n is volume ratio, and THET A n and PH In are orientation

angles for up to 3 rebar materials)

Material Properties

EX, ALPX (or CTEX or THSX), DENS (for each rebar) EX, ALPX (or CTEX or THSX), PRXY

or NUXY, DENS (for concrete)

Supply DAMP only once for the element (use MAT command to assign material property set).

REFT may be supplied once for the element, or may be assigned on a per rebar basis

Special Features

Plasticity Creep

Cracking Crushing

Large deflection Large strain

Stress stiffening Birth and death

Adaptive descent

LINK8 Description:

LINK8 is a spar which may be used in a variety of engineering applications. This element

can be used to model trusses, sagging cables, links, springs, etc. The 3-D spar element is a uniaxial

tension-compression element with three degrees of freedom at each node: translations in the nodal x,

y, and z directions. As in a pin-jointed structure, no bending of the element is considered. Plasticity,

creep, swelling, stress stiffening, and large deflection capabilities are included.

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Figure 22 LINK8 GEOMETRY

LINK8 Input Summary

Nodes:-I, J

Degrees of Freedom:-UX, UY, UZ

Real Constants:- REA - Cross-sectional area ISTRN - Initial strain

Material Properties EX, ALPX (or CTEX or THSX), DENS, DAMP

Special Features

Large deflection ,Creep, Large deflection, Plasticity, Stress stiffening, Swelling , Birth and death

ANSYS MODEL

General

Element Types

Table: 1.2- Material Type

The element types for this model are shown in Table 3.1. The Solid65 element was used to

model the concrete. This element has eight nodes with three degrees of freedom at each node –

translations in the nodal x, y, and z directions. This element is capable of plastic deformation, cracking

in three orthogonal directions, and crushing.

A Solid45 element was used for steel plates at the supports for the beam. This element has

eight nodes with three degrees of freedom at each node – translations in the nodal x, y, and z directions.

Material Type ANSYS Element

Concrete Solid 65

Steel Plates and Supports Solid 45

Reinforcement Link 8

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A Link8 element was used to model steel reinforcement. This element is a 3D spar element

and it has two nodes with three degrees of freedom – translations in the nodal x, y, and z directions.

This element is also capable of plastic deformation.

Real Constants

The real constants for this model are shown in Table: 1.3. Note that individual elements

contain different real constants. No real constant set exists for the Solid45 element. Real Constant Set

1 is used for the Solid65 element. It requires real constants for rebar assuming a smeared model.

Values can be entered for Material Number, Volume Ratio, and Orientation Angles. The material

number refers to the type of material for the reinforcement. The volume ratio refers to the ratio of

steel to concrete in the element. The orientation angles refer to the orientation of the reinforcement in

the smeared model. ANSYS allows the user to enter three rebar materials in the concrete.

Each material corresponds to x, y, and z directions in the element. The reinforcement has

uniaxial stiffness and the directional orientation is defined by the user. In the present study the beam

is modelled using discrete reinforcement.

Therefore, a value of zero was entered for all real constants which turned the smeared

reinforcement capability of the Solid65 element off. Real Constant Sets 2 is defined for the Link8

element. Values for cross-sectional area and initial strain were entered.

Table: 1.3- Real Constants

Real Constant Element Type Constants

Real

Constants

for Rebar

1

Real

Constants

for Rebar

2

Real

Constants

for Rebar

3

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3.2.1 Material Properties

Three material models were given:

1. Material 1 for Concrete

a. Linear Isotropic

b. Concrete

c. Multi linear Elastic

2. Material 2 for Steel Plates

a. Linear Isotropic

3. Material 3 for FRP

a. Linear Isotropic

b. Bilinear Isotropic

1.

Solid 65

Material

Number

0 0 0

Volume

Ratio

0 0 0

Orientation

Angle

0 0 0

Orientation

Angle

0 0 0

2.

Link 8

Cross-

sectional

Area

(mm2)

50.26

Initial

Strain

(mm/mm)

0.0088874

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The values of Material Properties is shown in Table 3.3

Table: 1.4- Material Properties

Material Model No. Element Type Material Properties

1.

Solid 65

Linear Isotropic

EX 38,480

PRXY 0.2

Multi linear Isotropic

Strain Stress

Point 1 0.00036 9.8023

Point 2 0.0006 15.396

Point 3 0.0013 27.517

Point 4 0.0019 32.102

Point 5 0.00243 33.095

Concrete

ShrCf-Op 0.3

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ShrCf-Cl 1

UnTensSt 5.3872

UnTensSt -1

BiCompSt 0

HydroPrs 0

BiCompSt 0

UnTensSt 0

TenCrFac 0

Linear Isotropic

2. Solid 45 EX 2,00,000

PRXY 0.3

Linear Isotropic

EX 1,87,000

PRXY 0.65

3. Link 8 Bilinear Isotropic

Yield Stress 2050

Tang Mod 0.65

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Fig: 7. Stress- Strain Curve of Concrete

Numbering Controls

The command merge items merges separate entities that have the same location. These

items will then be merged into single entities. Caution must be taken when merging entities in a

model that has already been meshed because the order in which merging occurs is significant.

Merging key points before nodes can result in some of the nodes becoming “orphaned”; that is, the

nodes lose their association with the solid model. The orphaned nodes can cause certain operations

(such as boundary condition transfers, surface load transfers, and so on) to fail. Care must be taken

to always merge in the order that the entities appear. All precautions were taken to ensure that

everything was merged in the proper order. Also, the lowest number was retained during merging.

Commands Used

NUMMRG,NODE – To merge all nodes

NUMMRG,KP – To merge all key points

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Boundary Conditions

Displacement boundary conditions are needed to constrain the model to get a unique solution.

To ensure that the model acts the same way as the experimental beam, boundary conditions need to

be applied at points of symmetry, and where the supports and loadings exist. The symmetry boundary

conditions were set first.

(Go To Main Menu)

Solution

Define Loads

Apply

Structural

Displacement

On Lines

(Pick lines) & OK

(Lab2) All DOF (DOFs to be constrained)

(Value) 0

OK

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3.2.6 Analysis Type

The finite element model for this analysis is a simple beam under transverse loading. For the

purposes of this model, the Static analysis type is utilized. The Restart command is utilized to restart

an analysis after the initial run or load step has been completed. The use of the restart option will be

detailed in the analysis portion of the discussion.

(Go To Main Menu)

Solution

Analysis Type

Static & OK

3.2.7 Load Step Method

Step 1

(Go To Main Menu)

Solution

Solution Controls

Basic – Enter the values as shown below.

Step 2

(Go To Main Menu)

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Solution

Solution Controls

Nonlinear - Enter the values as shown below.

Step 3

(Go To Main Menu)

Solution

Define Loads

Apply

Structural

Force/Moment Value

On Nodes

Step 4

(Go To Main Menu)

Solution

Load Step Opts

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Write LS File

(Value) Load Step file number n, 1 &OK

Step 5

(Go To Main Menu)

Solution

Define Loads

Delete

Structural

Force/Moment Value

On Nodes- Pick All

Step 6

Repeat the procedure from step 1 to step 5 with different load values.

Step 7

(Go To Main Menu)

Solution

Solve

From LS File

(Value) LSMIN- 1, LSMAX- 6, LSINC- 1

Step 8

(Go To Main Menu)

General Post Processor

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Read Results

By Pick- Read

Step 9

(Go To Main Menu)

Time History Processor

Add

Nodal Solution

DOF

Choose Y- Component Displacement

Pick middle node & OK

Plot graph

The model for the analysis now ready it is shown in fig.23 with simply supported on both ends with

a uniform distributed load of 14.4 kN/m in fig. 24 which we already worked out in our previous

chapter 4 and the max stress in the section is 149.9 N/mm2 with the max. Deflection of 12.2 mm.

Figure 23 Model Of ANSYS

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Figure 24 Model Showing 14.4 kN/m UDL with simply supported at both ends

During the analysis it gives the convergence graph for the nonlinear analysis for concrete and FRP shown in fig. 25.

Figure 25 Nonlinear analysis graph during analysis

14.4 kN/mm

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Figure 26 Stress along the length of the beam.

In figure 26 the stress along the length of the bar is shown. During the design we get stress in the reinforcement was 483.4 N/mm2 and during the analysis the max. stress is 479.9 N/mm2

Figure 27 Top stress in the beam

479.9823

479.9823

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In fig. 28 the max. deflection in the beam is shown which is 12.03 mm and according to our calculation the long term deflection was 12.2 mm

Figure 28 Deflection in the beam

The analysis show the time dependent results occur due to loading and crack pattern in the section. In fig 29 it shows the first crack and in fig. 30 it show the final cracks present in the beam.

Figure 29 Initial crack in the beam Figure 30 Final crack of the beam

Deflection = 12.02 mm

My = 12.02

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Chapter 7 Costing

FRP bars are two to three times higher than conventional material but an FRP composite element or

structure can be cost competitive only if the total life time is assessed. On a per kilogram basis FRP

composites are more expensive than traditional construction materials. For a realistic cost

comparison other factors should be included less material is required because

• Higher specific strength

• Fabrication costs are lower

• Lower transportation

• Erection costs are generally lower

for structures made of FRP composites in most cases life of the composite structures will be longer

than that made of traditional materials and will require less maintenance during its life span.

Since it is a non-corrosive material so the maintenance cost is very less and to this we can use his

section the:

• Bridge deck.

• Diaphragm wall

• Footing sections

• Beams

The transportation cost and maintenance cost are very less because of its less weight which can be

loaded and transported more in a truck as compared to conventional material.

INTRODUCTION

FRP has some excellent properties as a structural material. Its application to bridges offers a

possibility to solve problems that bridges made of conventional materials are facing today such as

corrosion and damages incurred early in the life-cycle of a structure. Presently, FRP’s unit price

is usually rather more expensive than that of other conventional materials. This may increase

the initial cost of the FRP superstructure and is one of the obstacles deterring widespread use of

the material in FRP bridges.

In order to evaluate the benefit of using FRP in bridges, it is important to consider FRP’s life

cycle cost (LCC) including the cost for maintenance. There has been some research1)-3) on the

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cost benefit of FRP structures; however, because some of those studies begin with the design of

the structures and include many suppositions, the LCC estimates of FRP structures are not so

reliable.

With this in mind, the authors tried to evaluate the LCC of an actual FRP footbridge, remaining as

faithful to actual conditions as possible. The case study is based on an FRP footbridge constructed

in Okinawa, Japan, in 2000. It is called “Okinawa Road Park Bridge” and is pictured in Figure .

View of the Okinawa Road Park Bridge

THE STRUCTURES FOR THE CASE STUDY

A FRP footbridge and PC footbridge crossing a 4-lane road were considered as the case models.

The bridges are located close to the seashore and severely affected by sea salt.

The main girders of the FRP footbridge are made of hand lay-up FRP; pultruded FRP is used for

the stiffeners, decks, and floor systems. Both types of FRP were made of glass fiber and vinylester

resin. Parts of the FRP footbridge were made in several factories within the Tokyo area, assembled

in a factory in Tokyo Bay, and then shipped to Okinawa.

Wall type piers and steel pipe pile foundations were used in the substructure for both bridges.

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Model cases of FRP and PC bridges

FRP bridges PC bridges

Concept Two span girder bridge

with GFRP C-girders

Single span deck girder bridge

with hollow post-tension concrete

beams

Length 37.8m 36.0m

Span 19.7m+17.2m 35.0m

Width 4.3m 4.3m

Live load 350kgf/m2 for main girders

500kgf/m2 for decks

CALCULATION METHOD OF LCC

Direct construction costs of the initial cost and the maintenance cost for both FRP and PC bridges

were calculated based on the design reports for both bridges. LCC was obtained by the equations:

LFRP bri. = IFRP bri. + MFRP bri.

LPC bri. = IPC bri.. + MPC bri.

L: Life-cycle cost

I: Initial cost

M: Maintenance cost

We did not calculate the cost for disuse neither did we consider the discount rate to discount future

costs to the base year. Initial costs were calculated for both the superstructure and substructure.

Maintenance costs were calculated only for the superstructure. The authors tried to set realistic

suppositions in situations where no data existed. In this study, the authors made some assumptions

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for unknown conditions and simplified the calculation. Hence the values of the costs in this study

do not indicate the real values of the Okinawa Road Park Bridge itself.

RESULTS

Initial costs

PC footbridges

Five types of superstructure were roughly designed for the PC footbridges. A deck girder

footbridge with hollow post-tension concrete beams was selected after considering multiple

viewpoints, including economy, workability, structure, view, and maintenance. Table 2 shows the

model cases of the PC footbridge. CASE-1 is the base case with two types of corrosive protected

cases added. CASE-2 adopts epoxy resin coated reinforcing bar and PC tendon. CASE-3 also

adopts coated bar and tendon, with the addition of a paint coating on the concrete surface. The

calculated the initial cost of each superstructure is: 48,240,000JPY, 50,620,000JPY and

54,370,000JPY respectively. As regards the substructure, two piers (Pier 1 and Pier 2) were roughly

designed for each of three alternatives. The best results are shown in Table 2. The total cost of the

substructure was 10,130,000JPY.

FRP footbridges

The initial cost of FRP bridges is roughly divided into three categories: (1) materials, (2) assembly,

and (3) mold for hand lay-up. Table 3 shows the initial cost of FRP bridges. The initial cost of the

FRP superstructure was 73,600,000JPY. The base model case (CASE-4) of the FRP footbridge has

some special points, for example, it is the first real FRP footbridge in Japan and it is located on

the seashore, suggesting that it may be possible to reduce its initial cost. The authors considered a

modified case (CASE-5) for FRP bridges so as to reduce its initial cost. These modifications were:

(1) change of handrail to aluminum, (2) change of design in the joint part of main girders, and

(3) sharing of mold by two bridges. The result of the modified initial cost became 62,350,000JPY.

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Table 2: Model cases of PC bridges and initial costs (Unit: 1000JPY)

CASE-1 CASE-2 CASE-3

Corrosion

protection for the

None Coated

reinforcing bars

C d PC

Coated reinforcing

bars Coated PC

tendon

Initial cost for the

48,240 50,620 54,370

Substructure system Pier 1: 6 Steel pipe piles (φ600mm-9mm,

L=17.5m) Pier 2: 4 Steel pipe piles (φ600mm-

Initial cost for the

10,130

Total Initial costs 58,370 60,750 64,500

Table 3: Model cases of FRP bridges and initial costs (Unit: 1000JPY)

CASE-4 CASE-5

Modified points for the

superstructure

Standard FRP bridge based on

the real bridge

Aluminum handrail

Change of joint parts of the main

girders

Sharing the mold by 2 bridges

Initial cost for the

superstructure

73,600 62,350

Substructure system

Pier 1: 2 Steel pipe piles (φ500mm-9mm, L=15.0m)

Pier 2: 4 Steel pipe piles (φ500mm-9mm, L=18.0m) Pier 3: 2

Steel pipe piles (φ500mm-9mm, L=12.0m)

Initial cost for the

substructure

6,910

Total Initial costs 80,510 69,260

There are three piers (Pier 1, Pier 2, and Pier 3) for the substructure of the FRP footbridge. When

comparing the two pile systems, driven steel pipe piles and PHC (Pretensioned Spun High Strength

Concrete) piles with installation by inner excavation, the steel pipe piles substructure showed better results

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in this case.

Comparing the total costs including both the superstructure and substructure, the difference of the initial

cost of the modified FRP footbridge (69,260,000JPY) was only 10% higher than the initial cost of the

corrosion protected PC footbridge. This result suggests FRP bridges have significant competitive power

even when considering the initial cost.

Maintenance costs

PC footbridge

Inspection and repair are the main maintenance considerations for bridges. Only the costs for repair were

considered in this study. The costs for inspection were omitted because it seems there are not large

differences in the inspection of PC and FRP bridges.

For the PC bridges, the authors estimated the penetration of chloride ion into the concrete after the

construction, and the repair was set when the concentration of chloride ion at steel reinforcing bars reached

1.2 kg/m3. Replacement of covering concrete and surface coating was selected as the repair method for

the PC bridges. The life of the surface coating which protects against chloride ion penetration was set

at 15 years and 30 years, and repair of the surface coating was calculated in these intervals. Table 4

shows the results of the repair costs.

FRP footbridge

Since the Okinawa Road Park Bridge is relatively new, there is not enough information on its repair and

maintenance requirements. However, five years after its construction, stainless steel bolts were replaced

because of corrosion due to the severely corrosive environment. This amounted to 1,000,000JPY. We

therefore considered the same scale of repair may be required at the same interval within a severely

corrosive environment and set the repair

cost for an FRP footbridge at 1,000,000JPY at 5-year intervals. In the modified case of FRP footbridges,

the repair cost was also modified by adopting highly durable bolts. The cost is 3,500,000JPY and the

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repair interval was set at 40 to 50 years.

Repainting is the major repair concern for FRP footbridges. There will be no corrosion for FRP structures

caused by weak points of painting such as edges or bolt parts like a painted steel structure because

FRP does not corrode. Hence, we set the repainting interval based on the decrease of thickness caused

by the deterioration of the painting material. The repainting interval was set at about 120 years based

on the thickness (75 m) and the material (fluorine resin paint) of the paint. The repainting cost was

calculated and the result was 5,600,000JPY including the scaffolding for repainting.

LCC

Table 4 shows the results of initial cost, maintenance cost and LCC for both PC and FRP footbridges. At

50 years, LCC of the FRP footbridge was 90,510,000JPY; this is lower than the 50-year LCC of the

PC footbridge without corrosion protection. The lowest 50-year LCC was that of the PC footbridge with

epoxy resin coated reinforcing bar and PC tendon (CASE-2). However, the modified FRP footbridge

(CASE-5) showed the lowest 100-year LCC among our five cases. These results suggest that FRP

footbridges are more efficient when longer life is required in severely corrosive environments.

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Table 4: LCC results of both PC and FRP footbridges (Unit: 1000JPY)

CASE-1

CASE-2

CASE-3

CASE-4

CASE-5

Repair interval:

15 years

Repair interval:

30 years

Initial cost for

t t

48,240 50,620 54,370 73,600 62,350

Initial cost for substructures 10,130 10,130 10,130 6,910 6,910

Total the initial costs 58,370 60,750 64,500 80,510 69,260

Maintenance cost for 30

24,500 0 18,000 9,000 6,000 3,500

Maintenance cost for 50

42,500 0 27,000 9,000 10,000 3,500

Maintenance cost for 100

years

69,500 24,500 54,000 27,000 20,000 7,000

50 years LCC 100,870 60,750 91,500 73,500 90,510 72,760

100 years LCC 127,870 85,250 118,500 91,500 100,510 76,260

CONCLUSION

The result suggests that FRP bridges has a competitive edge over other types of construction in spite

of its initial cost and that FRP footbridges are more efficient when longer life is required in severely

corrosive environments.

The results from the FEM analysis are near to our manual design result so it can be concluded that the

section made up of FRP will behave like the model made in the ANSYS apart from the fire FRP is the best

option for the design consideration and can be used in non-compressive member, more research is needed

on the issues related to the fire susceptibility of the FRP in case of fire.

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On the cost part if we are considering the total life of the section is far more than Steel so the section made

with the frp can resist more load and very less maintenance is required to that section so the proper

environmental situation have to kept in consideration during LCC it can increase in the initial cost of the

project but if we are considering the total life of the section then it will cost bit lesser than steel.

Since FRP can resist three times more load that steel so we required less FRP in the section that also be

considered during the cost analysis.

Furthermore research needed to support the fact that FRP can be used in buildings where fire is a problem

and to improve its quality against fire.

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Chapter 8 Summery

This report give introduction of the FRP product, its manufacture process by the forming process,

advantages and disadvantages, limitations Material properties like corrosion, high strength, lightweight,

stability, finishes, design flexibility, thermal conductivity, and some of the physical properties like

density, coefficient of thermal expansion, some mechanical properties like tensile behavior

compressive behavior, shear behavior and effect of temperature on FRP bars etc.

It also include the chemical properties and its application in various form like sheet, tube, cover, beam,

slab, tanks, blades, strengthen the system also some of its marine application as well as some form of

pipe, piles, also in the aeronautics industry. The introduction of FRP bars is also given to give an idea

about the form of bars and its limitation and advantage over steel is also described in detail.

Various code used in the design, experiment and analysis is listed. Some of the codes are used just for

the detailing of the FRP beam and some of the codes are for the testing which is also tabulated inside

the report.

This report have a manual design problem is explained with all the design procedure as per ACI440.04r

and all the tables and equations references are given which are explained in the code. The design

problem is A simply supported, normal weight concrete beam with fc’ = 27.6 MPa is needed in a facility

to support a machine. The beam is an interior beam. The beam is to be designed to carry a service load

of wLL =5.8 kN/m an a superimposed service load wSDL =3.0 kN/m over a span of l =3.35m and the

result of the manual design is also listed at the end of the report.

FRP reinforced beam is analyzed using Finite Element Analysis the same section that we design in

the previous chapter is analyzed and result of that section are compared to give a relevant theory

about its behavior.

Costing of the FRP method of analysis of its cost as well as an example of LCC is also covered.

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Bibliography

(n.d.).

Car of the future in plastics, The Mercury (Hobart, Tasmania). (1946).

440, A. C. (2006). Guide for the design and construction of structural concrete reinforced with FRP bars.

440, A. C. (2008). Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures.

50 years of reinforced plastic boats, G. M. (2660). Retrieved from http://www.reinforcedplastics.com/view/1461/50-years-of-reinforced-plastic-boats-/

ABDELRAHMAN, A. A. (1995). SERVICEABILITY OF CONCRETE BEAMS PRESTRESSED BY FIBER REINFORCED PLASTIC TENDONS. Manitoba.

ACI, 4. (2002). State of the Art Report on Fiber Reinforced Plastic (FRP).

Amato, I. (1999). Time 100.

American Warplanes of World War II, David Donald, Aerospace Publishing Limited. (1995).

Baekeland, L. (2000). Plastics. UK history site.

Chris BURGOYNE, l. B. (2007). Why is FRP not a financial sucess. Why is FRP not a financial sucess.

Composite moulding . (2004).

Conrardy, W. P. (1971). Accelerating utilization of new materials, National Research Council (U.S.) Committee on Accelerated Utilization of New Materials, Washington, National Academy of Sciences – National Academy of Engineering, Springfield.

Dogan, F. H., Donchev, T., & Bhonge, P. S. (2012). Delamination of impacted composite structures by cohesive zone interface elements and tiebreak contact. Central European Journal of Engineering 2, 612-626.

Erhard, G. (n.d.). Designing with Plastics. 2006.

Jain, L. S. (2009). The role of FRP composites in a sustainable world.

MEDIA, N. (n.d.). Retrofitting of Existing Bridge Using Externally Bonded FRP Composite–Applications and Challenges. Retrieved from http://www.nbmcw.com/: http://www.nbmcw.com/articles/repairs-rehabilitations/1890-retrofitting-of-existing-bridge-using-externally-bonded-frp-compositeapplications-and-challenges.html

(1944). Moulded glass fibre Sandwich Fuselages for BT-15 Airplane, Army Air Force Technical Report 5159,.

New Chemical Substance. (1909).

Notable Progress – the use of plastics, Evening Post, Wellington, New Zealand, Volume CXXVIII, Issue 31. (1939).

Reinforced plastics handbook. (2004). In D. V. Donald V. Rosato.

Smallman, R. E. (n.d.). Modern Physical Metallurgy and Materials Engineering. 1999.

Page 107: Study of Fiber Reinforced Polymer Materials in Reinforced Concrete Structures As Reinforced Bar

Study of Fiber Reinforced Polymer Materials in Reinforced concrete Structures As Reinforced bar

Synthetic Resin – Use in Aircraft Construction. (1936).

Technology Intormatin, F. a. (n.d.). Department od science and technology, Gov.tOf India.

Tim Palucka and Bernadette Bensaude-Vincent. (n.d.). History of Composites, . Retrieved from http://authors.library.caltech.edu/5456/1/hrst.mit.edu/hrs

Tong, L. A. (2002). 3D Fibre-Reinforced Polymer Composite.

US Patent Number 2133235: Method & Apparatus for Making Glass Wool. (1933). First Slayter glass wool patent.

Valbona Mara, R. H. (2013). Bridge decks of fibre reinforced polymer (FRP): A sustainable solution.