Investigation of thermal performance of concrete incorporating different types of recycled coarse aggregates

To adopt sustainability in the construction industry, various nations around the globe are focusing on the utilization of recycled aggregate concrete (RAC). The thermal performance of RAC incorporating different types of recycled coarse aggregates (RCA) is unexplored in the current literature. In this study, the thermal performance of RAC incorporating RCA treated through different techniques including accelerated carbonation, soaking in lime with accelerated carbonation, soaking in acetic acid, soaking in acetic acid with rubbing, and soaking in acetic acid with accelerated carbonation is explored. Furthermore, dry density, compressive strength, water absorption, the volume of permeable pores, porosity, and pore size distribution of all the concrete specimens are also investigated. The thermal conductivity of RAC specimens is observed 27% lower than natural aggregate concrete (NAC) specimens. An increase in thermal conductivity is observed for RAC specimens incorporating treated RCA than RAC specimens with untreated RCA. However, the thermal conductivity values of RAC specimens with treated RCA are still observed lower than NAC specimens. A relationship is also developed by regression analysis of the test database to predict the thermal conductivity of RAC. The proposed relation can effectively predict the thermal conductivity of RAC incorporating untreated and treated RCA leading towards the development of guidelines for sustainable construction.