Study of the structural-functional lightweight concrete containing novel hollow ceramsite compounded with paraffin

[Display omitted] •Lightweight aggregate concrete (LWAC) containing novel hollow ceramsite (HC) compounded with paraffin is proposed and charactered.•The compressive strength of LWAC/HC-Paraffin is 41.9 MPa which could be used for structural application and has a good thermal cycle stability.•The 8.1 wt% paraffin introduced into energy storage concrete play an important role in regulating temperature fluctuation.•The LWAC/HC-Paraffin could effectively alleviate the contradiction between the strength of energy storage concrete and the amount of PCMs added. In this paper, a structural-functional lightweight aggregate concrete (LWAC) with novel hollow ceramsite (HC) compounded with paraffine was prepared and studied. The mechanical and thermal properties of LWAC with HC-Paraffin are investigated and multiple thermal cycles are tested to evaluate the stability of this novel energy storage concrete. Results show that, the energy storage density (Des) of HC-paraffin is 85.23 J/g in the temperature range 15 °C–45 °C and the latent heat of HC-paraffin is 51.09 J/g. Compressive strength of LWAC with HC-Paraffin is 41.9 MPa which fully meets the requirements of structural building application. The amount of paraffin (8.1 wt%) introduced by HC is relatively advantageous in the current energy storage concrete researches. Compare to control group, the peak temperature and temperature fluctuation of LWAC panel with HC-Paraffin reduce about 5.2 °C and 7.6 °C respectively during the thermal test. Morever, the LWAC with HC-Paraffin shows good stability of mechanical and thermal property. The compressive strength of concrete increases about 8.6 % and the thermal regulation ability of concrete panel has no obvious degradation after 100 thermal cycles. This research gives a new method for the shape stable PCMs which can be directly used in building envelope, providing an alternative for the application of PCMs in buildings.