Thermal Behavior of Concrete with Crushed Granite and Washed Gravel Aggregates
Soyingbe, A.A., Jago, A.C. and Ojebisi, I.O..
Department of Building, University of Lagos, Lagos State, 101017, Nigeria
DOI: 10.36108/laujoces/5202.51.0130
Abstract
The study investigates the influence of coarse aggregate on the thermal behavior of concrete, focusing on thermal expansivity and thermal conductivity. The research addresses the need for thermally efficient and dimensionally stable concrete in Nigeria’s tropical climate, characterized by high and fluctuating temperatures. Concrete specimens were prepared using a nominal mix ratio of 1:2:3 (cement: fine aggregate: coarse aggregate) and a water-cement ratio of 0.53 for both aggregate types. After a 28-day curing period, thermal expansivity was measured using a dilatometer and thermostat oven, while thermal conductivity was assessed using an RMO500 micro-ohmmeter. Results showed that concrete made with crushed granite had lower thermal expansivity (8.0 × 10⁻⁶ /°C) and lower thermal conductivity (0.47 W/m·K) compared to washed gravel, which recorded 12.0 × 10⁻⁶ /°C and 0.66 W/m·K thermal expansivity and thermal conductivity respectively. The findings suggest that crushed granite provides greater dimensional stability and better insulation, making it more suitable for temperature-sensitive applications and climate-resilient applications. The study concludes that aggregate selection has a measurable effect on concrete’s thermal performance. It recommends crushed granite for construction projects where durability and thermal regulation are critical.
Keywords: Coarse aggregate, Crushed granite, Thermal conductivity, Washed gravel, Thermal expansivity