Self compacting concrete Introduction
Inception of self compacting concrete (SCC), which flows under its own weight and does the compaction as well without mechanical vibration, was in 1988 to achieve durable concrete by Japanese researches. Since then various investigations have been carried out and practical structures such as wider bridges using in situ concrete in transportation, carried out in Japan and European countries, The SCC having advantages of high early strength ,durable structures, easy placement and many other advantage rather than traditional concrete, is widely used to precast concrete industry to form architectural designs.
SCC is highly workable concrete that can flow under its own weight through highly congested reinforcement sections without segregation and bleeding. Self compacting concrete should also have properties of rheology such as relatively low yield value to ensure high flow ability, a moderate viscosity to resist segregation and bleeding, and must maintain its homogeneity during transportation, placing and curing to ensure adequate structural performance and long term durability. The successful development of SCC offers beneficial of economically and wide engineering varieties.
The two main purposes of SCC during the plastic stage are flowability which can be achieved using the high dosage of superplasticizer and stability or resistance to segregation of the plastic stage mixture that is attained by increasing the total quantity of the fines or otherwise using the viscosity agent admixture