SLUMP FLOW AND MECHANICAL PROPERTIES OF CONCRETE INCORPORATING CONCRETE WASTE SLURRY AND RUBBER POWDER

A rapid growth in the construction industry has led to increasing by-product productions, particularly as concrete waste. Additionally, rubber wastes from used tyres pose significant environmental concerns due to its resistance against natural degradation. Due to the limited research on the combined utilization of both concrete waste slurry (CWS) and rubber powder, the novelty of this study lies in evaluating the combined effects of these two materials on the fresh and mechanical properties of concrete. Hence, the present study investigates the performance of CWS as a mortar component and rubber powder as a non-mineral filler. A testing series of mix design by volumetric proportioning comprises CWS, 10 mm coarse aggregates, and varying percentages of rubber powder (i.e., 5%, 7.5%, 10%, and 20%) were batched and tested. A total of 54 specimens, comprising 36 cubes and 18 cylinders, were prepared for compressive strength and splitting tensile strength testing, respectively. The slump flow results indicate that increasing rubber powder content reduces the workability of the concrete. Moreover, both compressive and splitting tensile strengths decreased with higher rubber powder content. Among the rubber-containing mixtures, mixture with 5% rubber powder achieved the highest compressive and splitting tensile strengths of 19.76 MPa and 2.20 MPa, respectively. Also, mixtures containing rubber powder exhibited less brittle failure. Overall, the results demonstrate the feasibility of utilizing CWS and rubber powder in concrete production.