Thermo-mechanical and Thermophysical Properties of Ferro-siliceous Sacrificial Concrete on Exposure to Elevated Temperatures

Abstract

Heavy density concrete made of hematite-based aggregates commonly known as ferro-siliceous sacrificial concrete (FSSC) can be used effectively against radiation shielding in case of nuclear melt down. However, performance assessment of such concretes on exposure to elevated temperatures are not available widely. In the present study, thermo-mechanical and thermophysical properties of hematite-based FSSC concrete are evaluated on exposure to elevated temperatures. The porosity and water absorption capacity of FSSC are investigated on its exposure to higher temperatures ranging from 30 °C to 1000 °C. Similarly, various thermo-mechanical [compression, split tension, modulus of elasticity (MOE)] and thermophysical (specific heat, thermal conductivity, thermal diffusivity, and thermal effusivity) properties are evaluated on exposure to elevated temperatures. The mechanical properties of the concrete such as compression, split tension, MOE decrease monotonically with increase in the exposed temperature. Porosity and water absorption of the concrete increases with the increase in temperature. Relationship between damage and the exposed temperature can be described by Weibull model. Thermophysical property such as specific heat of the concrete increases, while thermal conductivity, thermal diffusivity and effusivity decrease with the increase in temperature. Correlations for the variation in thermal conductivity, specific heat and thermal diffusivity are proposed. The variations in the mechanical and thermophysical properties are explained through the porosity variations and correlation coefficient between porosity and various mechanical and thermophysical properties.