Experimental Evaluation of the Properties of Recycled Aggregate Pavement Brick with a Composite Shaped Phase Change Material

Brick waste makes up a significant part of the solid waste that is generated from building demolition globally. The disposal of this waste consumes land, causes environmental pollution, and is a waste of resources. In order to use this construction waste and increase its functionality, two types of stable-shape PEG-400/SiO2 composite shaped PCM and Tet/SiO2 composite shaped PCM were studied and added to recycled aggregate pavement bricks, and two new types of composite shaped PCM recycled aggregate pavement bricks were created. SEM, DSC, TGA, and other test methods found the two PCMs to be successfully adsorbed by SiO2, and the setting effect of PEG-400/SiO2 was found to be better than that of Tet/SiO2. The physicochemical properties of both composite shaped PCMs remained stable within the TGA test temperature range. The prepared PCM was added to the recycled aggregate pavement brick. A comprehensive analysis of the properties of the composite shaped PCM recycled orthopedic pavement brick found the compressive strength and flexural strength of Tet/SiO2 PCM recycled aggregate pavement brick to be significantly higher than those of PEG-400/SiO2 PCM recycled aggregate pavement brick. With a recycled aggregate content of 60% and a compound shaped PCM content of 5%, the 28-day strength of the recycled aggregate pavement brick was found to be higher than that of the recycled aggregate pavement brick with a recycled aggregate content of 70% and a compound shaped PCM content of 10%. This study provides reference for the optimization and upgrading of the thermal storage performance of composite shaped PCM in practical applications, and is of great significance for promoting thermal energy storage development and expanding its application range.