Characterization of concrete containing RCA and GGBFS: Mechanical, microstructural and environmental properties

Abstract

This study presents the results of an experimental/analytical investigation on the development of eco-efficient concrete. In this study, natural aggregates (NA) were replaced by recycled concrete aggregate (RCA) with amounts of 0, 25, 50, 75, and 100% by volume. In addition, ordinary Portland cement (OPC) was replaced with ground granulated blast furnace slag (GGBFS) with amounts of 0, 15, 30, and 45% by volume. Workability and the hardened state properties such as the ultrasonic pulse velocity, the water absorption, the compressive strength, the splitting tensile strength, the flexural strength, and the impact resistance of twenty mixtures were assessed. This study also includes global warming potential (GWP) assessment. The results show that the use of RCA and GGBFS had a negative effect on workability, compressive strength and impact resistance and positive effect on GWP. Finally, given the results of the optimization, the use of RCA up to 50 vol% and the use of GGBFS up to 30 vol% is recommended.