Experimental study on hygrothermal characteristics of coral sand aggregate concrete and aerated concrete under different humidity and temperature conditions

In the low-latitude isolated island area, coral sand concrete (CSC) is gradually replacing aerated concrete (AC) due to its advantages of easy access to raw materials and good durability. This paper studies the hygrothermal characteristics of CSC and AC through experiments. The experiments analyzed the change in thermal conductivity of material in the dry state (within the temperature range of -20 to 50 degrees C) and the influence of humidity on thermal conductivity of material (at 25 degrees C and 35 degrees C, within the humidity range of 0-100%). At the same time, the water absorption coefficient and the sorption isotherms were obtained. The results show that the thermal conductivity is only slightly affected by temperature and does not increase monotonically with the increase in temperature. The change in thermal conductivity with relative humidity can be divided into three stages and can be fitted to a polynomial function. The effect of humidity on AC's thermal conductivity is more obvious than that of CSC, which is positively correlated with the hygroscopicity and porosity of the material. When the relative humidity changes from 0% to 100%, the thermal conductivities of CSC and AC increase by 39.25% and 89.35%, respectively. (C) 2019 Elsevier Ltd. All rights reserved.