Utilization of charnockite rock as manufactured-aggregate for construction industry: a case study from Thiruvakkarai quarry and M-sand plant in Tamil Nadu, India.

Environmental concerns and the depletion of natural sand resources demand sustainable alternatives for construction materials. This study evaluates the feasibility of charnockite rock as a source for manufactured sand and coarse aggregates for use in concrete and mortar. Rock aggregate and manufactured sand samples from the Thiruvakkarai region, Tamil Nadu, India, were analyzed for geological, petrographic, physical, chemical and mechanical properties. Charnockite exhibited high specific gravity, low water absorption and optimal density making it ideal for concrete production. Petrographic analysis revealed a mineral composition rich in quartz, feldspar and pyroxene, enhancing strength, durability and environmental resistance. Chemical analysis confirmed high silica content (58.05%) with minimal deleterious substances, ensuring compatibility with cementitious systems. The aggregates used in this study comply with the provisions of IS 383:2016. The key mechanical properties include an aggregate impact value of 8.9%, a Los Angeles Abrasion value of 36.3%, and an aggregate crushing value of 22.1%. These values indicate that the aggregates meet the required limits for concrete applications, ensuring adequate strength and durability. The results confirm the suitability of the selected aggregates for use in concrete, aligning with the prescribed standards. Manufactured sand from charnockite surpassed conventional river sand in 28-day compressive strength, establishing it as a superior alternative. Its use reduces dependence on river sand, mitigating environmental degradation, reduces carbon footprint and promoting eco-friendly construction. This research provides a comprehensive foundation for utilizing charnockite-based aggregates in infrastructure projects and promotes sustainable development in the construction industry.