What is SCC (Self Compacting Concrete )???
- SCC is modern innovation- does not require vibration for placement and compaction.
- Flowing consistency, High Performance, Uniform quality.
- Most revolutionary development in concrete construction for several decades.
About
A special type of concrete of flowing consistency to obtain high performance, better and more reliable and uniform quality. The guiding principle for this type of concrete is that the sedimentation velocity of a particle is inversely proportional to the viscosity of the floating medium in which the particle exists.
Why Self Compacting Concrete
The existing concrete has faced criticism for its lower strength and difficult to obtain consistent quality. Requirement of skilled worker for compaction in conventional concrete.
Difficult to use mechanical compaction for….
- Underwater concreting
- Cast in-situ pile foundation
- Columns with congested reinforcement
Benefits of SCC (Self Compacting Concrete )
- Faster Construction
- Reduction in situ manpower
- Better surface finish
- Easier placing
- Improved durability
- Greater freedom in design
- Thinner concrete sections
- Reduced noise level
- Safer working environment
The Requirement for Self-Compacting Concrete
- Filling ability
- Passing ability
- Segregation resistance
SCC(Self Compacting Concrete ) should have
- Low coarse aggregate content
- Increased paste content
- Low water powder ratio
- Increased super plasticizer dosage
- Viscosity modifying agents
Self Compacting Concrete can be distinguished
- Powder Type: Increasing the powder content.
- Viscosity Modifying Agents Type: Adding viscosity modifying admixture.
- Combined Type: Increasing the powder content and using VMA.
Test Methods for Compactibility
Although many test methods have been developed for SCC but none has been standardized and the tests are not perfected.
- Filling Ability: Slump flow test, T50 cm slump flow test, V-Funnel test.
- Passing ability: J-ring test, U-box, L-box.
- Segregating Potential: Settlement column Test, Seive stability test, Penetration test.
Complexities involved in SCC (Self Compacting Concrete )
- Higher paste volume results in greater shrinkage and creep.
- Higher strength achievement leads to reduced workability to unacceptable level.
- Lateral Formwork Pressure.
- Limit of flow distance of the concrete.
Conclusion
- We can reduced the in-place cost and maker a safer working environment for the workers.
- SCC can be effectively placed in most congested areas and also where normal methods of vibration are not possible.
- Further research are required to interpret influence on the hardened properties of SCC more precisely.
- The cost of SCC is 10-15% higher than the conventional concrete.