Flow Characteristics of Recycled Coarse Aggregates (RCA) based Self-Compacted Concrete (SCC)

Abstract

The desire of humans increasing day by day to build new and high quality structures and to demolish the old structures. The demolished concrete is supplies to direct land fills and provides serious risk to the environment. In recent years, using recycled aggregates (RCA) as a substitute for natural aggregates in concrete has become of great interest to researchers. In meantime the use of RCA becomes sustainable and environmental friendly. The application of concrete in slabs, beams, columns specially areas of congested reinforcement requires high degree of compaction that is impossible to achieve at the site. For this purpose the self-compacted concrete (SCC) is the better solution. SCC is one that can flow under its own weight and fill the formwork completely without any need of compaction or vibration efforts. In this regards this experimental study has undertaken to investigate the flow behaviour of RCA based SCC. The natural crushed coarse aggregates were replaced by RCA at 0%, 20%, 40%, 60%, 80% and 100%. The fresh properties were evaluated through filling ability, passing ability and segregation resistance tests. The results revealed that all the fresh properties of RCA based SCC is depends on the percentage of RCA. As percentage of RCA increases the workability of concrete decreases. The workability is adjusted by increasing the suitable dosage of SP. Furthermore, it is also noted that all the values of freshproperties lie within the required limits of EFNARC.