self consolidating concrete-designing & tsting
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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
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