Use of agglomerated Micro-encapsulated phase change material in cement mortar as thermal energy storage material for buildings

Abstract

Globally it is reported that the building sector consumes more energy than other energy consuming sectors. Among the various solutions developed to reduce energy consumption, use of phase change material (PCM) in buildings is considered as an effective sustainable technique. Recent limited studies carried out on use of micro-encapsulated PCM (MIC-PCM) reported that breakage of MIC-PCM shell results in drastic reduction of strength of concrete and phase changing properties of MIC-PCM. Hence, as a preventive measure, in this study agglomerated MIC-PCM (AMIC-PCM) with bio based PCM in core encapsulated in thicker formaldehyde based shell is incorporated in flowable cement mortar. Firstly, material characterization of AMIC-PCM is carried out to study its phase change temperature, latent heat capacity, thermal conductivity, and specific heat capacity. From thermal stability test, it is observed that the bio-based AMIC-PCM can resist temperature up to 230 °C without any degradation. In the present study, AMIC-PCM is used at dosages of 5% and 10% (by weight) as partial replacement of fine aggregate in mortar mix. Experimental outcomes of this study indicates that adoption of 10% dosage of AMIC-PCM reduces the flow of mortar, compressive strength and flexural strength drastically. Although, there is strength reduction of mortar due to low intrinsic strength of AMIC-PCM, however results of the SEM analysis indicate that there is no micro-encapsulation damage in mortar mix. Further, it is to be noted that despite the strength reduction, the mortar mix with 10% dosage of AMIC-PCM is found to satisfy the strength requirement for making non-structural mortar board, to increase the thermal mass of building.