Latest developments i t d i tin concrete admixtures

29th October 200829th October 2008

Programme

Intro to concrete admixturesI Self-compacting concrete

History, testing, project references Latest developments in SCC Latest developments in SCC

QuestionsQ

Introduction to concrete admixturesconcrete admixtures

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History of admixture developments

ConcreteConcrete

History of admixture developments

development of VEAsdevelopment of VEAs

performanceperformance

PolyacrylatesPolyacrylatesPolycarboxylatesPolycarboxylates

development of VEA sdevelopment of VEA s

Hyper-plasticiser

NaphthalenesulphonatesNaphthalenesulphonatesMelaminesulphonatesMelaminesulphonates

Super-plasticiser

1950 1970 1980 1990 2008

LignosulphonatesLignosulphonatesPlasticiser

Plasticconcrete

Rheoplasticconcrete

Self compactingconcrete

Admixture performanceAdmixture performance

Type Typical dosage % % water brandby weight of cement reduction name

Modified Lignosulfonate (MLS) 0.2 - 0.6 < 10 Pozzolith

NaphthaleneSulfonate (BNS) 0.8 - 1.5 < 26 Rheobuild

Polycarboxylic ether (PCE) 0.5 - 1.3 > 40 Glenium

Performance of plasticising admixtures

8090

100

Polycarboxylate

40506070

o

w

[

%

]

Lignosulphonate

Melaminesulphonate

10203040

F

l

o

Polyacrylates

Naphthalenesulphonate

010

0 30 60 90 120 150 180

Time [min]Time [min]

Self-compacting concreteconcrete

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ContentsContents

Why do we need it?

History & Definition of SCC

Testingg

Opportunities & benefits

Job references / case studies

Next generation SCC

The problem

Inadequate & incomplete compaction dramatically lowers

The problem

Greatly reduced strength (1% voids reduces 28 days strength by

Inadequate & incomplete compaction dramatically lowers the quality of concrete:

more than 5%)

Lack of compaction of surface layer leads to poor durabilityperformance (durability closely associated with the permeabilityperformance (durability closely associated with the permeabilityof the surface layer of a concrete structure)

Poor appearance (surface finish)( ) Cube results not representing actual castings Inconsistent hardened properties (different permeabilities) in Inconsistent hardened properties (different permeabilities) in

various locations, enhancing the ingress of aggressive substances.

FACTSFACTS

More than 90% of repair materials go to new construction sites

Ab t 100 000 t 200 000 Dh f i t i l About 100,000 to 200,000 Dhs of repair materials are consumed in a 40 story tower, on vertical elements alone.

On average the cost of repairs (in materials only) adds about On average, the cost of repairs (in materials only) adds about 20 to 30 Dhs/ m3 of concrete.

5 Million Dhs were consumed in a single project for repairs.5 Million Dhs were consumed in a single project for repairs.

40% of consultants time and efforts dedicated to inspection of repairs.p

End of Service life : When you start making the first repair

The solutionThe solution

Design the concrete mix so thatNO NO

external compaction is required !

What is SCC?What is SCC?

Definition:Definition:Definition:Definition:

highly flowable, yet stable concrete that can spread readilyinto place and fill the formwork without any consolidationand without undergoing any significant separation.g g y g p(by Khayat, Hu and Monty: Proc. 1st. Intl. RILEM Symposium, SCC, Stockholm 1999)

Flowing concrete without segregation and bleedingFlowing concrete without segregation and bleeding,capable of filling spaces and dense reinforcement orinaccessible voids without hindrance or blockage.(by EFNARC, Technical Committee, Self Compacting Concrete, London 2000)

Types of SCCTypes of SCC

A.A. PowderPowder typetype Optimising the concrete structureby increasing the fines (

The European Guidelines for Self-Compacting ConcreteSelf-Compacting Concrete(Specification, Production & Use)

In order to enhance the acceptance of SCC a joint project groupconsisting of :

BIBM (European Precast Concrete Organisation), CEMBUREAU (European Cement Association), ERMCO (European Ready-mix Concrete Organisation)ERMCO (European Ready mix Concrete Organisation), EFCA (European Federation of Concrete Admixture Association) and EFNARC (European Federation of Specialist Construction Chemicals

and Concrete Systems)

Published the "European Guidelines for Self-CompactingConcrete in 2005.

EN206-9 & EN12350-8 to 12EN206-9 & EN12350-8 to 12

Test MethodsTest Methods

Characteristic Test method(s)

Flowability and filling ability Slump-flow test (EN12350-8)

Viscosity T500 Slump-flow test or V-funnel test(EN12350 8 9)(EN12350-8 or 9)

Passing ability L-box test (EN12350-10)

Segregation Segregation (sieve) stability testSegregation Segregation (sieve) stability test(EN12350-11)

Consistence classesConsistence classes

Slump-flow Slump-flow in mmSlump-flow Class

Slump-flow in mm

SF1 550 to 650SF1SF2SF3

550 to 650660 to 750760 to 850

Viscosity V-Funnel Time (s)Class

VF1 < 9VF2 9 to 25

SCC vs. high slump concrete

Fill Box

g p

Fill BoxNormal Concrete (high slump, 200 mm+)

Fill BFill BoxSCC

Testing SCCTesting SCC

Where can SCC be used?

PilesPiles

Columns

Beams

Slabs

Precast

Rafts

Heavily reinforced elements

Areas of limited accessAreas of limited access

Anywhere that concrete is required !

SCC Project Referencesj

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SCC Project ReferencesSCC Project References

1st SCC pour in the UAE

February 2001

DXB International Airport,T i l 3Terminal 3

Why SCC?Why SCC?

- The main contractor was looking for means to enhance his work programme and for early completion of the project.

- Reduction in concrete repairs was also another aim.

Cylinder strength No. of columns Volume

45/20 180 2 500 345/20 180 2,500 m360/10 62 2,000 m380/20 78 2 500 m380/20 78 2,500 m3

7,000 m3

Advantages Offered:Advantages Offered:

Speed of construction: The use of SCC reduced the columns ti l f 7 d ( i i l d i t t i 3 l )casting cycle from 7 days (original design to cast in 3 layers),

to one day.

No remedial works required, therefore additional savings in manpower and materials.

The client was sure of the high quality and durability of the columns.

Marina Heights Tower-DubaiBasement walls

Consultant: RMJMConsultant: RMJM

Contractor: Dutco Const.Co.

Grosvenor House HotelTransfer beams (heavily reinforced)

C lt t A hConsultant: ArchonContractor: Nasa Multiplex

Sewage Treatment PlantEmirates Hills

Pump inletPump inlet

Palm JumeirahSewage Treatment Works

Consultant: Ace ConsultantsContractor: Target Engg.

SCC pumped from the side walls and flowing upwardsupwards.

Consultants: De Leuw Cather IntlConsultants: De Leuw Cather Int l

Contractor: Al Muheiry

SCC raft

12,500m3 (3 pours of 2,300m3 + 1 pour of 5,600m3)

Current status

SCC raft pourSCC raft pour

Value Engineering-Value EngineeringSummary:

To RMC To Contractors To Clients/Engineers

Efficient Fleet Utilisation. Speed of construction Early completion.

To RMC To Contractors To Clients/Engineers

Less wear & tear onequipment.

Less wear & tear onEquipment.

Enhanced durability,extended service life.q p

(concrete pumps)

Market Differentiation.

q p

Optimisation & reduction ofmanpower

Design benefits (on elements sizes).Market Differentiation. manpower

Savings in repair costs

(on elements sizes).

Noise reduction & environmental benefits

Savings in vibrators cost

environmental benefits.

The next generation of gself-compacting concrete

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Smart Dynamic Concrete (SDC)For a new generation of highly fluid concretes

Solving the dilemmaSolving the dilemma

Self-compaction Robustness

Costeffectiveness

Obj ti f th j tTraditionallyVibrated Concrete (TVC)

Self-CompactingConcrete (SCC)

Objective of the project was to develop SCC mixes with cement Concrete (TVC) Concrete (SCC)

Robust mix No vibration

contents of 350- 400 kg/m3so as to be used in normal

ready mixed concreteLow stickiness

Good price

High speed

Great surface

SDCready mixed concrete.

Good price Great surface

Fields of Application Made for day-to-day use

TVC SDC SCCApplications for fits to the following applicationsTVC SDC SCC

Special

Applications for: fits to the following applications

vertical: walls & columns (W)driver: surface quality

n

t

y

p

e

W

C

20% driver: surface quality

horizontal: floors (C) and

A

p

p

l

i

c

a

t

i

o

F

80%SDC

horizontal: floors (C) and foundations (F)

driver: labour productivity

Slump100-125 150-175

driver: labour productivity

Use SDC to convert high slump to true self-compacting concrete

Construction Benefits

B fit

Adding value to concrete

M lti i it ti

Specifier + general contractor

BenefitsEconomical Savings in cement

U t 40% f t l i

Multi-win situation

ContractorReady-mix producer

Up to 40% faster placing Up to 5x higher labour productivity Easy to produce

Ecological Less cement, less CO2 Higher durability Specifier + general contractorg e du ab ty

Ergonomic No vibration No noise Low stickiness

Contractor

Features & CostsMaterial cost in % per m3 concrete

FeaturesFeatures

Fines: Cement content >350 kg Slump flow: 60-70 cm

125%

150% 134%

Strength: C35 C50 Robust mix-design with

day-to-day raw material 75%

100%

125%100% 108%

day-to-day raw material

Self-compacting25%

50%

75%

M i l l i0%

TVC SDC SCC

Fi & Ad i t A t

SDC

Material cost analysis

TVC: reference SDC: 8% higher

Fines & Admixtures Aggregates SCC: 34% higher

Cost savingsg

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Smart Dynamic ConstructionFull cost analysis

ApproachApproach

Stop-watch all activities Full cost analysis

5 process steps1. Outside formwork2 Reinforcement2. Reinforcement3. Inside formwork4. Concrete placing5 Remove formwork5. Remove formwork

Target Material cost impact (incl equipment cost) Material cost impact (incl. equipment cost) Labour cost impact

Process Step 1 Placing outside formwork

TV Difference between TVC and SDCC

Formwork savings (less wear and tear)

Re-use of shutters increased by 5x

SDC

Process Step 2Reinforcement

TV

Difference between TVC and SDC Same activities

C Same materials

Impact on total wall cost Material cost: 0 Dhs

SDC

Labour cost: 0 Dhs

Process Step 3Placing inside formwork

TV Difference between TVC and SDCC

e e ce be ee C a d S C

Formwork savings (less wear and tear)

Re-use of shutters increased by 5x

SDC

Process Step 5Removing formwork

TV

Difference between TVC and SDC Less cleaning with SDC

C Much higher surface quality with SDC For fair faced concrete: remedial work

savings of 25-75%savings of 25 75%

Impact on total wall cost

SDC

Reduced labour (no. & time)Reduced repairs (material & time)

Full Cost Analysis Summary

300 TVC SDC Labour cost impact: -6%

200

250

- 3%

p

Material cost impact: -6%Plus:

100

150 + 8%

- 43%

0% Improved surface quality Higher safety

Faster constr ction

50Formwork Reinforcement Concrete Placing

- 43% Faster construction

In horizontal applications, the benefits of SDC pay off even better!

Smart Dynamic ConcreteSmart Dynamic Concrete

Summary

Technology Features Benefits in the field ofTechnology Robust mix design Tailor-made superplast. Exclusive VMA

Features Fines < 400 kg 60-70cm slump flow Self-compacting

Benefits in the field of Economics Ecology Ergonomics Exclusive VMA Self-compacting Ergonomics

Smart Dynamic Construction

New:

SDC makes unique mix-design optimization possible

SDC combines the advantages of both, TVC and SCC

RheoMATRIX is the key to solve paradox requirements: robustness (stability) + fluidity

SDC is cost effective: it saves labour and material costs

Summaryy

Development of admixturesTh d f SCC

I The need for SCC Testing of SCCest g o SCC

SCC in use

SDC and RheoMATRIX

Ultimate labour savingUltimate labour saving

Chemistry-based innovationsf th t ti i d t

Thank you for for the construction industryyour attention!