Contribution of activated mortars with phase change materials to the energy efficiency of buildings

Abstract

Currently, the high energetic demand in the construction sector, especially associated with the buildings climatization requirements, it is a subject of extreme importance and with urgent action needs. This issue is related to the strong dependence of climatization equipment based on non-renewable energy sources, mainly oil, coal and natural gas. The possibility of incorporating Phase Change Materials (PCM) into constructive solutions early began to attract the attention of several researchers, however there are several types and techniques for incorporating PCM in constructive solutions. Thus, the main purpose of this study consists in comparing the performance of cement mortars incorporating PCM microcapsules, using the encapsulation technique, and the performance of cement mortars with addition of a non-encapsulated PCM, without any previous treatment, through the direct incorporation technique. It was possible to verify that the PCM presence modify the main properties of the mortars, namely resulting in a greater water absorption capacity by immersion and a decrease in the flexural and compressive strengths. However, the two techniques revealed a very satisfactory and equivalent thermal behavior in terms of control and attenuation of extreme temperatures inside the buildings. Nevertheless, the non-encapsulated PCM present a significantly lower acquisition cost, thus increasing the economic efficiency and possibility of technology implementation.