Study On Improving The Wet Condition Of Rural Residence Floor By Porous Materials

Thermal environment is an important part of the building environment,humidity not only affect health,but also reduce the durability of the building envelope.With the rapid development of China’s economy,building condensation problem has been basically solved in the city.But in rural areas of southern China,the humid air is prone to condensation on the ground floor in the spring and summer transition season.How to solve the problem of ground condensation has become an important subject to improve rural living environment.Design standards for energy efficiency of rural residential buildings and Code for design of building ground proposed to use microporous material on surface to condensation prevention.The use of hygroscopic porous material is a green,low-carbon,economical moisture-proof measure.But the current norms and standards only made recommendations,did not provide the parameter selection and evaluation,so the guidance on engineering design and applicatione is not strong.In this paper,the heat and moisture performance of hygroscopic ground was analyzed,hope to provide theoretical basis and reference for the actual project through this theoretical research.First of all,in order to get the current situation of rural ground,the humid level of the ground and the subjective evaluation of it in rural areas,this paper has investigated and measured the hygroscopic ground in rural areas of Chongqing.The survey results showed that the wet ratio of hygroscopic ground,such as tabia ground and raw ground,was lower than that of the non-hygroscopic ground,and the evaluation of the hygroscopic ground was generally better from the rural residents.Contrast measurement of the moisture condition and indoor themal environment between an earth house with tabia ground and a brick house with cement concrete ground were taken.The results showed that the humid level of the tabia ground was lower than that of the concrete ground,and the absorption capacity of earth was higher than that of the cement materials.In order to further quantitatively analyze the heat and moisture performance of the hygroscopic ground and its effect on the improvement,this paper combed the heat and moisture transfer mechanism of the porous material,and determined the boundary of the one-dimensional heat and moisture transfer of ground.Clay tiles ground,cement ground and glazed tiles ground were set up by WUFI software,and the heat and moisture performance of their surface layers,and their improvement effect on the wet condition was simulated and analyzed.The simulation results showed that the moisture absorption and desorption performance of the hygroscopic material was seasonal that moisture content of the material changed greatly during the wet season in spring and summer.Hygroscopic materials on the one hand can effectively reduce the relative humidity of the surface by moisture absorption,on the other hand improve the surface temperature by the process of heat release,thusby reduce the possibility of ground condensation effectively.Chongqing area suitable for use the hygroscopic material whose absorption capacity increased rapidly when the environmental humidity above 80% and moisture absorption of small when the humidity below 80%.It is noteworthy that ventilation should be strengthened during the moisture releasing period.