Preparation and properties of phase-changing energy-storing concrete

Butyl stearate was impregnated into pores of expanded perlite, and limestone powder wrapped up it to prepare phase-changing energy-storing aggregates (PCESA). Phase-changing energy-storing concrete was prepared by PCESA replacing some sand. Experiments of compressive strength and splitting tensile strength were carried out for phase-changing energy-storing concrete. The micro-morphology of phase-changing energy-storing concrete was characterized by using SEM images. Both phase transition properties of PCESA and specific heat capacity of phase-changing energy-storing concrete were characterized by DSC technique. The test results show that:The PCESA remain intact in phase-changing energy-storing concrete, and interfacial transition zone (ITZ) is typical attribute of phase-changing energy-storing concrete with good integrity between cement paste and PCESA, which leads to the increase of phase-changing energy-storing concrete strength relatively. The increase of PCESA volume fraction results in a rising of specific heat capacity of phase-changing energy-storing concrete due to the good thermo-physical performance of PCESA. When the content of PCESA is up to 20vol%, the phase-changing energy-storing concrete has a good mechanical and thermo-physical performance, and it is equally amenable to bearing capacity and building energy conservation.