Development, mechanical properties and numerical simulation of macro encapsulated thermal energy storage concrete

Abstract Macro encapsulated lauryl alcohol-lightweight aggregate (LA-LWA) was prepared for subsequent development of thermal energy storage concrete (TESC). The macro encapsulated LA-LWA was obtained by encapsulating the surface of LWA with epoxy and modified cement paste. From sealing performance test, it was found that after 150 thermal cycles the mass loss of PCM in LWA with epoxy coating was less than 1%. The thermal conductivity of TESC was lower than control LWAC while the compressive strength of TESC macro encapsulated with epoxy was around 30 MPa. Therefore, TESC can be used for structural applications. Based on the better performance of epoxy coated LWA, further investigations were carried out. The macro encapsulated LA-LWA was found to be thermally stable and reliable. From outdoor thermal performance test, it was found that TESC room model was efficient in reducing indoor room temperature. Computer simulations for the room model were then performed. It was found that PCM integrated walls showed best thermal and energy performance. Among different cities, the thermal performance in Changsha city was the best. Finally, it was shown that the application of PCM in a typical public housing flat in Hong Kong is economically feasible with a payback period of 14 years.