Phase change materials sheets for energy-efficient heat curing process: A potential idea and performance evaluation

Many countries experience long cold winter, which delays many in-situ concreting activities. Shifting to precast concrete systems is a common solution to continue and maintain construction progress. However, the heat curing process for precast elements represents a challenge for the precast industry due to its high energy consumption (i. e. high fossil fuels dependency and associated high carbon emissions). Therefore, this study examines the feasibility of utilizing micro-encapsulated phase change materials (MPCMs) to achieve a sustainable curing process. Both direct incorporation of MPCMs in the cementitious mixtures and covering specimens with MPCMs sheets were examined under a simulated heat-curing cycle. Results showed that covering specimens with MPCMs sheet eliminated drawbacks induced by MPCMs direct incorporation (i.e. leakage of paraffin, voids, and loss of function). Moreover, utilizing the MPCMs sheet allowed shortening the heat curing holding period by 50% (i.e. from 10 hrs to 5 hrs) while achieving 96% of the desired strength. Findings confirmed the high potential of using MPCMs sheets to cure, save energy, and boost the precast concrete industry's sustainability level.