Performance of recycled refractory brick fine aggregate on diverse properties of Portland slag cement based heat resistant concrete

Abstract

Utilization of industrial by-products generated through thermal processes is a critical approach in response to the industrialization and urbanization trends, may contribute to the creation of sustainable concrete, which might experience fire through its lifespan and its residual properties, are of specific interest. Hence, this innovation initiates a comprehensive experimental program to analyse the properties of novel heat resistant concrete, that blends Portland Slag Cement and Recycled Refractory Brick at distinct substitution levels (10,20,30,40,50,70, and 100 % of natural fine aggregate), including a control mix. The concrete samples are exposed to elevated temperatures (200,400,600,800, and 1000 °C) to assess the impact of Recycled Refractory Brick and develop a novel heat-resistant sustainable concrete, assuming the inherent heat resistance properties of Refractory Brick as it is prepared under high heating conditions. Subsequently, thermo-mechanical properties viz. weight loss, density loss, modulus of elasticity, ultrasonic pulse velocity, stress-strain behaviour, compressive strength, damage degree, failure pattern and Scanning Electron Microscopic analyses are executed. The experimental results displayed 1.01, 5.15, 6.01, 6.26 and 6.68 % of mass loss in the specimens after exposure to diverse elevated temperatures. The compressive strength significantly improved up to 29 %(10.57 MPa), 67 %(24.26 MPa) and 44 %(12.85 MPa) after exposure to 200, 400 and 600 °C temperature respectively compared to compressive strength at ambient temperature. The results pointedly indicate that higher substitution levels (70 and 100 %) have exhibited superior retention of mechanical properties compared to lower replacement levels after exposure to 800 and 1000 °C temperatures particularly. In authors’ view, substituting 10–40 % of natural fine aggregate with recycled refractory brick combining with Portland Slag Cement shows significant promise in the production of sustainable concrete intended for diverse applications under elevated temperature conditions.