RECYCLED AGGREGATE CONCRETE TECHNOLOGY: A COMPREHENSIVE REVIEW OF MECHANICAL PERFORMANCE, DURABILITY, AND ENVIRONMENTAL SUSTAINABILITY ASPECTS

Abstract

Recycled aggregate concrete (RAC) has emerged as a sustainable construction material capable of addressing environmental challenges posed by construction and demolition waste while conserving natural resources. This comprehensive literature review synthesizes recent peer-reviewed research on recycled aggregate concrete technology, focusing on mechanical performance, durability characteristics, and environmental sustainability. The review examines mechanical properties including compressive strength, tensile strength, and elastic modulus across varying replacement ratios. Durability performance is evaluated in terms of resistance to chloride ion penetration, carbonation, freeze-thaw cycles, and wet-dry cycles. Environmental impact assessment through life cycle analysis reveals that RAC can reduce carbon emissions by 25-40% compared to conventional concrete, particularly when supplementary cementitious materials are incorporated. Key findings indicate that moderate replacement rates (30-50%) of recycled coarse aggregate can achieve mechanical and durability performance comparable to natural aggregate concrete, while full replacement (100%) requires optimization through aggregate pre-treatment, improved mix design, and incorporation of supplementary materials. This review identifies critical research gaps including long-term performance prediction, standardization of design guidelines, and comprehensive assessment of multi-recycled aggregate concrete systems. The synthesis demonstrates RAC's viability as a reliable structural material while highlighting the necessity for continued research to optimize sustainability benefits without compromising performance