Effect of temperature and iron powder incorporation on the thermophysical properties of concrete

This study evaluates the thermophysical properties (thermal conductivity, volumetric heat capacity, thermal diffusivity and thermal effusivity) and the chemico-mineralogical properties of concrete containing iron powder at mixing ratios of 1:1.5:3, for use in construction. The thermal conductivity and volumetric heat capacity of the samples were measured in a temperature-controlled box using a CT meter at temperatures of 20 °C, 30 °C, 40 °C and 50 °C. Concrete specimens were prepared by adding different percentages of iron powder (IP) to natural sand (NS), at replacement percentages of 0%, 5%, 10%, 15%, 20% and 25%. The effect of iron powder incorporation on the thermal properties was analysed. The results of the study indicate that the percentage of iron powder and temperature both influence the thermal properties of the tested concretes. Compared with the reference concrete, the incorporation of 25% iron powder led to increases of about 2% in thermal conductivity, 1.11% in volumetric heat capacity, and 1.53% in thermal diffusivity at elevated temperatures. The results demonstrate that adding iron powder modestly enhances the thermal performance of concrete, making it more suitable for use in environments subject to temperature variations.