Effect of Maximum Aggregate Size and Powder Content on the Properties of Self-compacting Recycled Aggregate Concrete

The utilization of recycled aggregates and various industrial by-products is considered a sustainable strategy in the concrete industry. In this study, the effect of the maximum size of recycled coarse aggregate and the cementitious binder content on fresh and hardened properties of self-compacting concrete was investigated. Self-compacting concretes with maximum aggregate sizes of 9.5 mm, 12.5 mm, and 19 mm were prepared at water-to-binder ratios of 0.39, 0.42, and 0.45, respectively. For all mixtures, 100% recycled aggregate was used as coarse aggregate and 60% of cement was replaced by industrial by-products, i.e., fly ash and ground granulated blast furnace slag. The tests included slump flow, air content, hardened density, compressive strength, elastic modulus, and splitting tensile strength. The results showed that the increase in maximum aggregate size and binder content tended to improve both fresh and hardened properties of self-compacting concrete.