Self Consolidating Concrete

ByJeewapriya Alahakoon

Chemical DivisionSt.Anthony’s Hardware (Pvt) Ltd

Section - II

• Designing of SCC• Test Methods of SCC

Designing Of SCC• Parameters– Properties of Hardened Concrete

• Same as conventional concrete design (E.g.; Strength )• Fulfill BSEN 206 / BS5328 / ACI or any other accepted standards

- Properties of Fresh Concrete• Filling ability• Passing ability• Stability

☻ A Concrete mix only be classified as SCC if the above all properties are satisfied.

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SCC RheologyConflict between high flow & Segregation resistance

VMA

PCE

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Important parameters for successfulSCC mix

• Coarse Agg; Content – 25%- 35% from concrete volume

• Paste Fraction – 35% - 37%

• Powder Content or W / P ratio• Fine Agg; Content – 45% - 55% of FA / Total Agg;

• Low W/C• Air Content – can improve viscosity properties

• HRWR Admixture e.g. ADVA• VMA e.g. Vmar10p

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Important parameters for successfulSCC mix

H R W R + VMA

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Steps to Successful SCC mix1. Determine required Slump-Flow2. Select of CA & FA proportions

3. Estimate required Powder & Water content 4. Select Admixture5. Trial Batch6. Test7. Adjust mix proportion based on test result8. Repeat steps 5-7 as necessary

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Properties Selection Guidance Chem

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Testing Methods Of SCCChem

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Testing Methods Of SCC

Slump Flow TestChem

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•ASTM C 1611

•ACI 237 Committee report –

Common range 450mm – 750mm

•Abram’s cone – ASTM C143/C143M

•Base plate – 900mm x 900mm

SCC Flow Rate Test (T500) – ASTM-C1611

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•Time takes to reach 500mm(20”) diameter

•Typical Value 2 – 5 Sec;

SCC- J-Ring Test – ASTM C1621Chem

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•Limited to concrete with Max Agg; size of 25 mm.

•J-Ring

25mm thick, 300mm diameter rigid ring.

Max-16mm diameter, 100mm height rods in equal space.

(SFT value – J-Ring test value) < 50mm

Other TestsL- Box Test

Rheometer

U – Box Test

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Visual Stability Index (VSI) TestASTM-C1611

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BEST

WERST

Why VSI ?Chem

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Requirements for SCC Chem

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References

• National Ready mix Concrete Association, CIP-37, SCC, 2004.

• EFNARC, UK, Specification & Guideline for SCC, February 2006.

• Eric. P. Koehler, David. W. Fowler, Center for Transportation Research, The University of Texas, TX-DOT, Project-0-5134, SCC for Pre-cast Structural Application, August 2007.

• G.DE. Schutter, Guidelines for testing fresh SCC, September 2005.

• W.R. Grace & Co; North American Customer Service, Technical Bulleting, 2005.

• W.R. Grace & Co; High Performance Concrete, 15, December 2006.

• Prof. Wallervik.O.H , Rheology, My Way of Life, 36th Conference on Our World in Concrete & Structure, Singapore, August 2011.

• Chuah.K.P. , Elementis Rheological Additives, 2004.

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Chemical Division

St.Anthony's Hardware (Pvt) Ltd;

January 2013