High temperature performance of recycled fine concrete

The objective of this study is to explore the physical and mechanical behaviour of concretes comprising four different ratios of recycled fine (RF), namely (5%, 10%, 15% and 20%) along with that of a reference concrete (Cref-0%), under three different heating–cooling cycles (200 °C, 400 °C and 600 °C). The thermal properties of concrete during heating and cooling (20 °C – 600 °C – 20 °C) were also investigated. It was determined that the physical properties (mass loss and ethanol porosity) of recycled concrete (RC) with 5% of recycled fine (RC-5%) were similar to those of Cref-0%. At ambient temperatures, the higher the ratio of recycled fines, the lower the residual compressive strength and residual elastic modulus of the recycled concrete. After thermal loading at 600 °C, the residual mechanical properties of all types of concrete were equivalent, regardless of the content recycled fine.