Production of eco-friendly self-compacting concrete with recycled concrete aggregate

Abstract

In recent years, recycled aggregate concrete (RAC) has become a major focus of research due to its positive environmental impact. The objective of this paper is to investigate the influence of dosage of recycled sand and gravel on the fresh properties of self compacting concrete (SCC). Experimental program was conducted on SCCs made with different rates of substitutions (25, 50, 75 and 100%) of natural sand and gravel (NS, NG) with recycled sand and gravel (RS, RG) by volume. All mixtures were obtained with a constant W/C ratio of 0.38, sand-to-mortar (S/M) ratio of 0.5 and a superplasticizer dosage of 1.5% of binder by weight. For fresh properties, tests were conducted for slump flow, V-funnel, L-box and resistance to segregation. Rheometer apparatus in the rheological testing of fresh SCC was used to determine the rheological parameters. The results indicated that an optimum replacement level of recycled sand and gravel of 50% can be achieved without adversely affecting key fresh concrete properties, including filling ability, passing ability, and segregation resistance. In addition, a clear correlation was established between the empirical and rheological parameters of the self-compacting recycled aggregates concrete