Abstract:At present, for the study of the thermal conductivity of building materials containing moisture, the prediction model generally assumes that the materials containing moisture are uniform, and the experimental measurement usually adopts the uniform humidification scheme. However, the indoor and outdoor humidity and meteorological conditions influence the non-uniform distribution of moisture components in the process of moisture absorption and desorption, and the thermal conductivity of the materials is different under the same moisture content. In this paper, the moisture content of aerated concrete (AAC) , foam cement (FC) and red brick (RB) materials with different pore characteristics were tested, by analyzing the changing trend of thermal conductivity in the whole process of moisture-increasing and moisture-reducing, the changing characteristics of thermal conductivity in non-uniform moisture-distributing materials were studied. The results show that the thermal conductivity of AAC, FC and RB increases by 279%, 266% and 106%, respectively. The difference of thermal conductivity of the same moisture content AAC humidification process is about-20.2% ~ 63.4%, the difference of FC is about 14.5% ~ 53.3%, and the difference of RB is about-18.0% ~ 37.4%.