Development of Self-Energy Storing Engineered Cementitious Composites

In this study, microencapsulated phase change materials (MPCMs) were incorporated within engineered cementitious composites (ECCs) in attempt to develop a new cementitious material capable to self-store the thermal energy while presenting optimized ductility performances. For this purpose, MPCMs with a phase transition temperature of 18 degrees C and 6 degrees C were added to ECC mixtures at 10, 20, and 30% by silica sand replacements. The self-heat storage capacity was tested by assessing the inner temperature change of ECC system placed in an environmental chamber regulated at fluctuated temperatures varying from -10 degrees C to 32 degrees C with constant relative humidity. The effect of MPCMs on the fresh and mechanical properties of ECCs was investigated by measuring the flow diameter, compressive and flexural strengths, and deflection and cracking performance of different MPCM-based ECCs. In addition, SEM/EDS analysis was performed on core samples of various ECC mixtures to characterize the effect of MPCM on the microstructure of ECC. The results revealed that the heating/cooling behavior of ECCs highly improved with increased MPCMs contents. Mechanical strengths were not highly influenced by the use of MPCMs, especially at 10% and 20%, thus allowing the development of high ductility ECC mixes with thermal-energy storage ability under high and low temperatures.