Phase change materials composite boards and mortars: mixture design, physical, mechanical and thermal behavior

Abstract

Energy dependence is currently a serious problem faced by the European Union. In recent years there has been an effort to increase the use of renewable energy sources, which will allow for a sustainable increase in the energy independence of different countries. On the other hand, given the rising energy costs seen in recent years and the low income of families, energy poverty is increasingly a reality throughout Europe, especially weakening the most economically disadvantaged families. Thus, there is a need to combat this reality using renewable energies combined with functional and more energy efficient construction materials. In this study, composite boards based in mortars activated with phase change materials were developed. Initially, it was developed a study in the main properties of the PCM mortars based in the mechanical behavior, microstructure observation and thermal influence. Subsequently, PCM composite boards were developed and tested for their main physical and mechanical properties, in order to assess their possibility of inclusion in the market. Based in the results it was possible to conclude that the PCM incorporation in mortars and boards alters its properties from the physical, mechanical and thermal point of view. Regarding to the mortars characterization, there was a decrease in the flexural and compressive strength higher than 27 % and 26 % with the incorporation of non-encapsulated PCM, respectively. It was also observed a decrease in the microporosity, due to the more compact microstructure. Regarding to the thermal behavior it was verify a decrease in the maximum temperature of 6 % in summer situation and 9 % in spring season. On the other hand, there was an increase in the minimum temperature of 3 % in spring season. In the boards characterization there was an increase in the microporosity, due to the increase higher than 48 % of total porosity and 3 % in the water absorption by immersion with the PCM incorporation and a decrease in the flexural strength higher than 15 %. However, it was possible to conclude that the production of manufacturing boards based in PCM mortars can be seen as possible solution to increase the energy efficiency of buildings and decrease the energy poverty in the society.