Effects of elevated temperature on performance of recycled coarse aggregate concrete

Abstract

This experimental program determines the influence of elevated temperature on the performance of concrete containing varying percentages of recycled coarse aggregates. Natural coarse aggregates were substituted by 30%, 60% and 100% recycled coarse aggregates obtained from concrete debris of a demolished building. Glass powder, marble powder and rice husk ash were used as binder to replace 20% of Ordinary Portland cement to enhance the strength related properties of concrete mixtures prepared with 100% recycled aggregates. Moreover, waste steel wires were used as a reinforcement to explore the possibility of improving the mechanical properties of recycled aggregate concrete. Cylindrical specimens of different mixtures were exposed to four different temperatures (i.e., 25, 200, 400 and 600 °C), and later on tested for mass loss, ultrasonic pulse velocity test, compressive strength test and splitting tensile strength test. Although the tested properties of concrete decreased with the increase of exposure temperature, the residual compressive strength of recycled aggregate concrete at elevated temperatures was satisfactory and comparable with the control mixture.