Thermal properties of coarse RCA concrete at elevated temperatures

Abstract

An experimental investigation was carried out on the thermal properties of concrete made with coarse recycled concrete aggregate (RCA) in the temperature range from room temperature to 800 °C. Three different concrete mixtures were produced with replacement percentages of 0%, 50% and 100% coarse RCA. The thermal properties at elevated temperatures, including thermal conductivity, specific heat and thermal expansion were obtained from the tests. Test results in this paper show that the thermal conductivity of coarse RCA concrete decreases with increasing coarse RCA content. The development trends of thermal conductivity and specific heat with temperature are similar among concretes with different coarse RCA content. For thermal expansion, the concrete with 50% coarse RCA has a larger value than the concrete containing 0% and 100% coarse RCA at temperatures above 500 °C. Based on the test data, simplified equations were proposed to express the elevated-temperature thermal properties of coarse RCA concrete.