The effect of the incorporation of phase change materials on green concrete

Abstract

In advancing urbanization and industrialization, the escalation of construction and demolition waste has become conspicuous, paralleled by a discernible surge in energy requirements. Within the construction sector, these issues have garnered escalating attention from investigators. Phase Change Materials (PCMs), distinguished by their elevated energy storage relative to conventional sensible heat storage materials, stand out as pivotal. This work studied the integration of Recycled Aggregate with Phase Change Materials (RAPCM) replacement of natural aggregate in concrete. The overarching objective is to optimize the thermal performance of building envelopes, thereby mitigating peak energy demand. A part of free liquid PCM was directed to mix in concrete in the mixing process to achieve more PCM content. Five concrete mixes were prepared: reference concrete, 75% RAPCM, 100% RAPCM, 75% RAPCM + PCM, 100% RAPCM + PCM. The findings indicate that with an escalation in RAPCM content from 75% to 100%, there is a concurrent reduction in concrete density, compressive strength, and flexural strength by 4.0%, 6.1%, and 26.7%, respectively. By adding free PCM again on this basis, the concrete has reached the level of lightweight concrete, but its compressive strength continues to decrease, up to 50%.