Potential use of recycled construction and demolition waste aggregates for non-structural concrete applications

Promoting recycled aggregates from construction and demolition (C&D) waste for producing concrete will reduce the demand on conventional aggregates and it is an alternative to effectively manage C&D waste. Application of recycled C&D aggregates as a substitute to conventional aggregates in low strength concretes is the best way to initiate this in the industry. Therefore, this study focused on investigating the strength properties and the influence of time on the behaviour of strength gaining of concrete elements made by mixing the conventional aggregates and recycled C&L aggregates. The grade of the concrete was 25. The research methodology involved replacing the conventional coarse aggregates partially with 0 %, 20 %, 40 % and 60 % recycled C&D aggregates in concrete mixtures. Test cubes were cast for each percentage of the materials and other conditions were kept as constants. The test cubes were then subjected to compressive strength test under three test series. The test series were focused on different curing periods of the specimens as 7, 28 and 90 days to determine the behaviour of strength gaining with time. The conclusion drawn from the study is that it is feasible to substitute up to 40 % of coarse aggregates by recycled C&D aggregates in conventional low-intermediate strength concrete applications with the specified mix design.