1.1 Self Compacting Concrete (SCC)
Self compacting concrete is a self consolidating concrete defined as a Concrete which is able to flow under its self weight and to fill the formwork in complete, even in the presence of huge reinforcement, without using any vibration actions, whilst maintaining homogeneity. It was originally first developed in Japan, to overcome the problems caused by lack of complete and uniform compaction through vibrators. Self-compacting concrete is not affected by the shape and quantum of reinforcing bars or the enatchment of a structure and, due to its high-property of flowing easily a changeable quality and resistance to segregation it can be long distances (Bartos, 2000).
The Professor Hajime Okamura (1997) was the concept of self compacting concrete can be proposed in 1986, but the prototype was first developed in 1988 in Japan, by professor Ozawa (1989) at the University of Tokyo. This concrete was developed at that time to improvement the durability characteristics of concrete structures.
However, the Bureau of Indian Standards (BIS) has not brought out a standard mix procedure although number of agencies and researchers carried out extensive investigations to establish rational mix design procedures and self compactibility testing methods. Since then different research works have been carried out and SCC has been used in practical structures in Japan, mainly by large companies. Investigations for establishing a rational-mix design method and self compactibility testing methods have been carried out from the viewpoint of making a standard concrete. When the Self Compacting Concrete is cast, so there is no additional inner or outer vibration is necessary for the compaction. It flows like a “honey” and as a very smooth surface level after placing of the SCC. With this quantify to its mistura, this concrete consisting using of materials like in conventionally vibrated concrete, which are cement , aggregates and water , with the adding of mineral and chemical admixtures in same as the another proportions. Usually, the chemical admixtures are used for the high-range of water reducers (Super Plasticizer) and Viscosity Modifying Agents, which change the rheological properties of concrete. Mineral admixtures are used as an extra fine material besides cement, and some cases, they replace cement. In this study cement content was partially replaced with mineral admixture is used, i.e., fly ash. Admixtures that are improves the flowing and strengthening properties of concrete.