The Effect of Silica Fume and Slag Cement on the Dynamic Modulus of Recycled Aggregate Concrete

Over the years, the production of concrete waste and hazardous waste (B3) has been increasing. The accumulation of concrete waste and B3 waste can disrupt environmental sustainability. To address this issue, researchers have implemented green construction practices that support the Sustainable Development Goals (SDGs) for 2030. One of the innovative ways is to create environmentally friendly concrete by utilizing concrete waste as recycled coarse aggregate (RCA) and using B3 waste such as silica fume and slag cement as cement substitutes. In this research, the proportions of RCA used were 50% and 100%, which were varied with silica fume proportions of 5%, 10%, and 15%, as well as slag cement proportions of 10%, 20%, and 30%, based on the weight of the cement. By combining RCA and B3 waste in concrete, it is important to understand their impact on the quality of the concrete. Therefore, a non-destructive testing method was conducted to evaluate the dynamic modulus. The research revealed that, in general, utilizing silica fume and slag to the 50% RCA increased the dynamic modulus. However, when using 100% RCA, the dynamic modulus value of the concrete, in general, decreased.