A CRITICAL REVIEW ON EFFECTS OF REPLACEMENT OF NATURAL SAND WITH MANUFACTURED SAND ON STRENGTH PARAMETERS OF CONCRETE

Abstract

The global construction industry is currently grappling with a critical shortage of natural river sand, a crisis compounded by the severe environmental degradation resulting from unregulated riverbed mining. As the industry seeks sustainable alternatives, Manufactured Sand (M-sand) has emerged as a frontrunner. This paper provides a comprehensive evaluation of M-sand produced through the systematic crushing of hard stone as a functional replacement for fine aggregates in concrete. Unlike the rounded grains of river sand, the angular geometry and micro-surface roughness of M-sand facilitate a superior mechanical interlocking within the cementitious matrix, potentially enhancing both durability and structural integrity. Through a comparative analysis of M20 and M22 concrete grades, this study investigates the performance shifts associated with incremental replacement levels (25%, 50%, 75%, and 100%). The synthesised data suggests that a 50% substitution ratio represents a "sweet spot," consistently achieving optimal compressive strengths, specifically 19.2 N/mm² for M20 and 21.2 N/mm² for M22 mixes over a 28day curing period. Additionally, the study explores the synergistic effects of incorporating silica fume as a mineral admixture to further refine the concrete’s pore structure. The findings conclude that transitioning to Msand not only mitigates the ecological footprint of sand extraction but also offers a technically robust and economically viable solution for the future of sustainable infrastructure.