Structures

Pro

cess

es

Properties

Performance

Metals

CeramicsPolymers

Composites

Construction Materials

Asphalt Cement

WoodsConcretes

Sand

It is the form of Silica .It is formed by decomposition of sandstones due to various weathering effects.

Fine minerals The order of 0.1 to 1.0 mm diameter Fill voids between the coarser aggregate

Types of Sand1) Natural Sand – obtained from pits, shores, riverbeds

seabed's…2) Artificial Sand – obtained from crushing of stones.

Sand

Types of Sand (depending on fineness)

1) Coarse Sand – retaining on sieve 4.75 mm2) Fine Sand – passing through sieve 4.75 mm

Uses1) PCC, RCC, PSC2) Cement mortar, Lime Mortar3) Coarse Sand - plaster on Ex. Wall, Fine Sand – Plastering on

Internal Wall4) Below flooring material5) In filtration plant.

STONECheapest, Durable and obtained from ROCKProperly dressed and shaped before it is used.

Classification of Rocks1) Geological – Igneous Rock, Sedimentary & Metamorphic2) Physical – Stratified, un-stratified and Laminated.3) Chemical – Siliceous, argillaceous, calcareous4) Hardness of Stone - Very hard, hard, medium, soft

5

•Marble

•Slate

Uses of Stone

6

•Marble - Exterior Application

•Slate Flooring

•Limestone with Granite

•Polished Surface

•Rough Texture

•Granite Material

Uses of Stone

Foundation, roofs floors, railway ballast, road metal.

Stone Blocks – Wall, Foundation, Ornamental Facial work.

Slate – Roofing & Flooring Lime Stone Slabs – Flooring,

paving and roofing Granite – bridge abutment,

piers, flooring, kitchen otta, steps, table top etc…..

Marble – floors, tiles, Ornamental Facial work.

STEEL Steel is an intermediate form between Cast

Iron and Wrought iron. Steel are highly elastic, ductile,malleable, forgeable, weldable.

Grades of Steel –

Fe250, Fe415, Fe500Fe = ferrous metalNumber = Yield stress in N/mm²

STEEL

Cast iron is iron or a ferrous alloy which has been heated until it liquefies, and is then poured into a mould to solidify.

Wrought iron is an iron alloy with a very low carbon (0.1 to 0.25) content in contrast to cast iron, and has fibrous inclusions, known as slag. Wrought iron is tough, malleable, ductile and easily welded.

Malleable is a material's ability to deform under compressive stress.

Classification of STEEL

Mild Steel - Used as structural and

Non-Structural Steel, in form of I, C, L, round, flat shapes. It is Fe 250 as yield strength is 250 N/mm²

Tor Steel – used in RCC work,

It has low ductility and low bend ability.It is Fe 415 & Fe 500 (yield stress)

High Tensile Steel – usually in form of WIRES of high tensile strength (tendon)

Used in prestress concrete. 1500 to 2350 N/mm² (Ultimate stress)

Mild Steel High Tensile steel

Tor Steel

Structural member in trusses, beamsNon Structural components for grills,

stairs, windows, doors etc ….Steel Tanks, Steel Pipes.TOR steel in RCC member.Tendons in PSC.Corrugated sheets as roof coveringMild Steel in manufacture of tools,

equipments, towers, machine parts etc….

Uses of Steel

CONCRETE(CEMENT + Fine Aggregate+ Coarse

Aggregate + WATER) PROPORTION ( 1:2:4), (1:3:6), (1:4:8)GRADE M15, M20, M25……. And so on……M- Mix Number – Compressive strength after 28 days in

N/mm²(A cementation reaction between water and the mineral in

cement provide a strong matrix and good compressive strength)

Common construction materialStrong hard but brittle

Universal Testing Machine

Concrete Types

(PCC) Plain Cement Concrete(RCC) Reinforced Cement

Concrete(PC) Precast Concrete(PSC) Prestress Concrete

Types of Concrete

PCC – (cement + FA+ CA +Water)Strong in compression and weak in tensionHard and DurableManufacturing – Hand mixing or Machine Mixing.

USES –

a) Foundation masonry, base of foundation.b) Gravity Dam and Retaining Wallc) Below Flooring.d) Leveling work over PLINTH.

Types of Concrete

RCC - ({Cement + Sand+ CA +Water} this mixture is Reinforced in STEEL)

Strong in compression and tension Hard, Durable and bear all types of stresses. R/f may be MILD STEEL Or TOR STEEL BAR. Minimum Grade used is M20. Manufactured on site may be Hand mixing or Machine Mixing.

USES – a) Construction of multi storied buildings.b) Road pavement.c) Water tanks, bridges, concrete pipes.d) Concreting of beams, columns, slabs, footing etc.

R.C.C.

Cement

Water

Sand

Aggregate

Steel

Concrete

Advantages of R.C.C. a) Highly durable, Fire-resisting. b) Monolithic character provides rigidity to structure. c) Fluidity of concrete and flexibility of Reinforcement

make it possible to mould into various shapes. d) Cost of maintenance is negligible.

PRECAST CONCRETE (P.C.) Casted in Separate form and then placed. Casted in casting yard or on building site. After casting, transported and placed in position by

cranes.

PC units are – 1) Hollow concrete blocks2) Tiles3) Pipes4) Roof Slabs5) Electric Poles6) Stair Case7) Rail Sleepers

Uses Of P.C

Casting structural Elements like BEAMS, COLUMS, SLABS, WATER TANKS, GIRDERS, FRAMES, TRUSSES, SEPTIC TANKS, WATERSUPPLY AND DRAINAGE PIPE, FENCING POST, ELECTRIC POLES, CAISSIONS, TRAFFIC BARRIERS, ROAD DIVIDERS, CONRETE PILES, BRIDGE PIERS ETC………

Manufacturing- (Reinforcement – Mould – Concreting ) Advantages- Mould can be reused when production is in bulk Better quality control as production is in factory Smooth surface may be achieved and plastering may be

avoided.

Precast Concrete Examples

PreStress Concrete.

Def:- Concrete in which reinforcing steel bars/tendons are stretched and anchored to compress it and thus increase its resistance to stress.

Methods – A)Pre-tensioningB)Post-tensioning

Pre-tensioning

Steel reinforcement is first tensioned with hydraulic jack and then concreting is done and harden for 28 days.

Used for LONG SPANs. Higher tensile strength is obtained.

Post-tensioning

Steel reinforcement is enclosed in ducts or metal sheets, concreting is done and harden for 28 days, then these steel reinforcements are tensioned with the help of hydraulic jack and anchored.

Used for LONG SPANs Higher tensile strength is obtained.

Uses of PSC PSC girders in bridges. Railway Sleepers Electric pole Beams of large span Pile foundation Slabs

Advantages Size of structural member is reduced Members can resist shocks, vibration, impact Mostly high quality material is used.

•Pile for foundation

STRUCTURAL COMPONENTS STRUCTURE OF BUILDING IS DIVIDED IN Two

CATEGORIES- 1) Superstructure – (above GS)2) Substructure – (Below GL)

Components of Substructure:a) Foundationb) Plinthc) Damp proof Course (DPC)

Foundation Total Load of SUPERSTRUCTURE is transmitted to the FOUNDATION BED via SUBSTRUCTURE. Def.:- ‘Structure which supports the superstructure’ Transmitting media – usually made up of RCC Foundation Bed – made up of hard (Nat/Art) bedrock or

soil.

FUNCTION OF FOUNDATION Transfer and Distribute the load uniformly. Prevent from Uneven settlement To maintain stability of structure from overturning and

sliding Forms a level for laying the masonry courses.

BEARING CAPACITY

Structure will be safe if the bearing capacity of the soil is satisfactory.

Bearing capacity = Maximum Load carrying capacity

ULTIMATE BEARING CAPACITY- Max. avg intensity of applied pressure that the

underlying area can carry before its shear failure of material.

Safe Bearing Capacity = Ultimate BC -----------------------

FOS

FOS

1.5 to 2 – Temporary structures2 to 3 - Shallow Footing2 to 6 - Pile Foundation5 to 10 – Rock Structures2.5 - Buildings FOUNDATION

Value of FOS (difference in loads, ground strata, position of Ground water)

SETTLEMENT OF FOUNDATION It is the vertical downward movement of the

foundation. Amt. of settlement may be different for different

types of soil Settlement is a time dependent processClayey Soil – Very Gradual (Long time and more)Sandy Soil – Quick and less.

TYPES OF SETTELMENT Uniform Settlement Differential Settlement

Type of settlement

•Uniform Settlement

•Sliding / Overturnin

g

•Differential Settlement

UNIFORM SETTELMENT

Vertical DOWNWARD movement of the total base of structure is EQUAL.

US causes when - Uniformly distributed load.- Uniform soil / rock beneath

NO Damage to structure. Excessive US may damage-- Water supply & Drainage lines- Telephone & Electric Cables.

DIFFRENTIAL SETTLEMENT Vertical DOWNWARD movement of the total

base of structure is Non - Uniform. DS causes when - Distributed load on the structure is uneven- Different soil / rock beneath the foundation. DS is a DANGEROUS Settlement.

•P

P•P

•P•P

•P1

•P2

•P3

Types of Foundation

Foundation ( Based on Depth)

SHALLOW FOUNDATION

Spread Footing – Used to distribute Concentrated Load from Superstructure over a wider area. (WALL FOOTING)

STRIP FOOTING

1) Simple Strip Footing 2) Stepped Strip FootingUsed below light structure. Garden wall or Compound Wall.Temporary structures.

•Simple Wall Footing•Stepped Wall Footing

•Step•Offset

ISOLATED / PAD FOOTING (Column Footing)

These are used to support Individual Column. They may be in different shapes- Rectangular- Square- Circular- Sloped Used for modern RCC building.

COMBINED FOOTING When loads on adjacent columns are very high

or BC of the soil is less, two columns are grouped together to form a combined footing

Differential settlement is reduced as the base is common.

Case 1: Same Loading on 2 column (W1 & W1) – Rectangular Footing

Case 2: Diff Loading on 2 column (W1 & W2) – Trapezoidal Footing

W1 W1

STRAP / CANTILEVER FOOTING Provided in following conditions:

Case I – If it is not possible to provide footing exactly below the column. (boundary restriction)

Case II – Distance between the 2 columns is so large that combined footing is not possible.

In such cases a cantilever beam connects these 2 columns.

DEEP FOUNDATION

Pile Foundation

A sender Column capable of transferring the structural load to the deep underlying layer.

End of column is usually sharp.At the G.L the pile is covered with PILE CAP, on which COLUMN is constructed.

END BEARING PILE Load is transferred to Hard Strata, through soft soil strata, at a greater depth.

Pile rests on HARD STRATA at greater depth.

FRICTION PILE Load transfer is by SKIN FRICTION without any

end bearing. Soil offers resistance to pile by virtue of

FRICTION.

SUPERSTRUCTURE (topics)

TYPES OF LOADS-• DL & LL• Wind Load

EARTHQUAKE CONSIDERATIONSTYPES OF CONSTRUCTION• Load bearing• Framed• Composite

MASONRY• Stone masonry• Brick Masonry

Superstructure PART OF STRUCTURE ABOVE Plinth Level (G.S)Components- (Wall, Roof, Door, Windows, Flooring,

Slab etc……) Plinth – Part of Structure lying above

Substructure and below Superstructure. Loads acting on Superstructure – DL, LL, Wind Load,

H.W Q1. Write comparison of Superstructure and Substructure

TYPES OF LOADS

1) Dead Load (D. L)2) Wind Load (W. L)3) Live Load (L. L)4) Earthquake Load (Eq. L) These loads may act simultaneously (W.L, Eq.

L may vary)

DEAD LOAD Load of Material – Self wt. of Bldg.

Components. D.L = (Volume x Unit Weight of material) (KN/m3)

MATERIAL UNIT WEIGHT (KN/m3)

PCC 24

RCC 25

Brick 22

Steel 78

Brick Masonry 18

Stone Masonry 22

LIVE LOAD Movable Superimpose load acting on

structure.(Occupant, Furniture, Equipment, machinery, etc……)

It is usually consider acting uniformly . In case of Multistoried building, FULL LOAD on

each floor is not considered for calculating Foundation Load.

Minimum L.L. depends on type of Building.TYPE (Purpose) Min

L.L.((KN/m²)

Residential, Hospital 2.00

Office Room, Small Work Place 2.45

Bank, Reading Hall 3.00

Class Room, Restaurants 4.00

WIND LOAD W.L is effective in ‘HIGH RISE BUILDING’. Wind Pr. {P = kV²}P = wind pressure in (KN/m²)k = Coefficient depending on wind velocity, size,

shape of structure and Atm. Temperature. Ht. < 3 times the width (W.L may be

neglected)

EARTHQUAKE LOAD

TYPES OF CONSTRUCTION Methods of constructing SUPERSTRUCTURE.

1)LOAD BEARING STRUCTURE 2)FRAMED STRUCTURE3)COMPOSITE STRUCTURE Choice for the method of construction depends

on – - Number of Floors, - Area Covered,- Type of Structure,- Bearing Capacity of Land,- Economy

LOAD BEARING CONSTRUCTION

Load transferred to wall as roof and floors are connected to the wall

Roof & Floor – Wall – Wall Footing – Underlying Strata Economical up to 2 storeys (as no of storeys

increases wall thickness increases & carpet area reduces)

Feasible where HARD STRATA is available at Shallow depth.

Now a days – Temporary and important structure are build.

E.g. - Shaniwarwada, C.O.E. Pune, Central Bldg.

FRAMED STRUCTURE Slab – Beam – Column – Footing – Underlying

Soil. Used for MULTISTORIED BUILDING. Frame is constructed by RCC Speed is faster compared to LBS If HARD STRATA NOT available at considerable

depth, PILE foundation or RAFT foundation is designed.

COMPOSITE STRUCTURE

COMBINATION of L.B.S & F.SOUTER WALL – L.B.S.Columns and Beams are provided

intermediately. Floors and Roofs are supported by walls and

frames. Used for Industrial Sheds, Warehouses where

spans are long.

THANK YOU….