Experimental study on the effect of superplasticizer on workability and strength characteristics of recycled coarse aggregate concrete

Abstract

Protecting the natural resources in every developing county like India, is one of the major problems. The vast and fast construction work deplete the natural resources and polluting the environment by emitting enormous quantity of carbon dioxide and dust as well. Therefore, reusing the structural concrete components as recycled coarse aggregate (RCA) as another source in preparation of new concrete, which can be considered advantageous to the sustainability of the virgin resources. But the RCA concrete results in lower mechanical properties than the natural coarse aggregate (NCA) concrete. This paper attempts in getting the shortcomings related to RCA use and the possible improvements of some properties in RCA concrete through the use of superplasticizers. As RCA has more water absorption property than NCA, water reducing admixtures are thus vital for RCA concrete for conserving the alike properties as that of NCA concrete. The properties of RCA concrete without plasticizers taken as control mix, were compared with the RCA concrete with plasticizers. The properties like compressive strength, split tensile strength, flexural strength and density of RCA and the fresh properties like workability in terms of slump and compaction factor were compared. Sorptivity test was conducted to examine the compactness of both the concrete mixes. The experimental outcomes demonstrate better properties of RCA concrete with plasticizers than the control mix.