Influence of recycled concrete gravel and sand in self-compacting concrete (SCC)

Abstract

This work consists of studying the effect of recycled concrete gravels and sands on the fresh properties of self-compacting concrete (SCC). The SCC formulations were manufactured with a fixed water/cement ratio (W/C = 0.40), the same ratio of G/S = 1, and a superplasticizer dosage of 2.2% of the weight of the cement. By weight, recycled concrete gravel and sand replaced natural gravel and sand in four different types of self-compacting concrete by 25, 50, and 75%. Fresh tests were carried out, such as the spreading test, the L-Box test, the V-funnel flow time, and the J test. Ring. The tests showed that replacing some natural gravels and sands with recycled ones gives SCCs good properties in their original state when it comes to how well they work for passage, filling, and not separating. The substitution of recycled concrete gravels and sands by up to 50% improves the workability and therefore increases the Vfunnel flow speed of SCCs. While the incorporation of 75% recycled concrete gravel and sand leads to a reversed behavior of the SCC.