Characterization of innovative mortars with direct incorporation of phase change materials

Abstract

The utilization of innovative cement mortars with direct incorporation of non-encapsulated phase change materials (PCM) is a solution for minimize the high energetic consumption of buildings, due their ability in regulate the temperature inside the buildings. The development of construction material with PCM, based in macro and microencapsulation techniques has been developed. However, the utilization of these techniques has a high cost. The direct incorporation of non-encapsulated PCM allows the cost reduction, due to the absence of PCM encapsulation and complex incorporation techniques, representing an innovative and promising way to contribute significantly for the energy efficiency of buildings. Four different compositions were developed and characterized according to their physical, mechanical and thermal properties. The physical behaviour was evaluated based in some properties in the fresh and hardened state such as workability, density and water absorption. The mechanical performance was evaluated based in the flexural and compressive strengths. Finally, the developed mortars were thermally tested based in temperature laws representative of the north part of Portugal, with a resource to a climatic chamber and a data acquisition system. The obtained results showed a decrease in the water absorption due to the partial PCM occupation of the mortar pores. On the other hand, it was observed a slight decrease in the mechanical properties do to the presence of higher liquid binder ratio. Finally, regarding to the thermal tests it was verified a decrease in the extreme temperatures and cooling and heating needs. The mortar with 20% of PCM presented the higher impact in the interior temperature regulation.