Enhancing Concrete Sustainability: Assessing the Impact of Construction and Demolished Waste Aggregates on Strength and Rapid Chloride Permeability as a Durability Indicator

Abstract

The construction industry is adopting sustainable practices by using Construction and Demolished (C&D) waste aggregates in concrete production. This study investigates the impact of C&D waste on concrete’s compressive strength and rapid chloride permeability (a vital durability Indicator), examining the relationship between aggregate replacements, strength, and chloride permeability. The goal is to guide the creation of robust and eco-friendly concrete formulations. The results show that higher levels of C&D waste aggregate replacement lead to reduced compressive strength and increased chloride ion permeability, compromising concrete’s durability. Notably, a 25% replacement of C&D fine aggregates demonstrates the highest compressive strength at 36.71MPa, while a 100% replacement of C&D coarse and fine aggregates yields the lowest at 19.73MPa. RFA 25%, RCA 25%, and RFA 25% + RCA 25% mixtures experienced significant improvements in compressive strength, with gains of approximately 15.98%, 13.18%, and 12.36% at 7 days, and 15.73%, 12.33%, and 10.80% at 28 days, respectively. Concrete maintains satisfactory durability when replacing up to 50% of C&D fine aggregates, up to 75% of C&D coarse aggregates, and up to 25% of C&D fine + coarse aggregates.

Keywords

• construction and demolished (c&d) waste
• recycled aggregates
• rapid chloride permeability test
• sustainable concrete