The effect of phase change materials on the physical and mechanical properties of concrete made with recycled aggregate

Abstract

With the world’s population increasing, the issue of energy consumption has become increasingly prominent, particularly during the building operation phase, where substantial energy is required for heating and cooling. Presently, the energy necessary for buildings is sourced mainly from the combustion of fossil fuels, leading to not only energy scarcity but also severe environmental pollution and ecological damage. Furthermore, rapid urbanization has generated a lot of construction and demolition waste. To address these challenges, one promising approach is the incorporation of phase-change materials in recycled aggregate from construction and demolition waste to replace the raw materials of concrete. In this study, the phase-change material suitable for the thermal comfort requirements of buildings was selected and combined with recycled aggregate to replace the natural aggregate in concrete. All the materials used were characterized and three compositions were prepared. From the results, the workability of concrete increased with the phase-change materials added. Regarding water absorption performance, the incorporation of functionalized recycled aggregate presented a small water absorption performance. However, the mechanical performance decreased with the phase-change materials used. This work provides data for the application of phase-change materials in green concrete.