HPC produced with CDW as a partial replacement for fine and coarse aggregates using the Densified Mixture Design Algorithm (DMDA) method: Mechanical properties and stability in development

Abstract

This study was designed to examine the mechanical properties and durability of high-performance recycled aggregate concrete (HPRAC) containing high percentages of construction and demolition waste (CDW). In the samples, natural coarse aggregate was replaced with recycled coarse aggregate at respective ratios of 30%, 40%, and 50%, and natural fine aggregate was replaced with recycled fine aggregate at respective ratios of 40% and 50%. The concrete mixtures were designed using the Densified Mixture Design Algorithm (DMDA) method with low cement content and water binder (w/b) ratios of 0.3, 0.4, and 0.5. Concrete samples were tested for compressive strength, splitting tensile strength, ultrasonic pulse velocity (UPV), electrical surface resistivity (ESR), thermal conductivity (TC), water absorption (WA), and rapid chloride penetration and were analyzed using scanning electron microscope (SEM) micrographs for microstructure. The results support a negative relationship in concrete between CDW content and strength and durability development as well as between the w/b ratio and mechanical properties and durability. However, all of the HPRAC specimens designed in this study using the DMDA method achieved a high strength range, good durability, and stability over curing time.