夏热冬冷地区典型外保温系统的湿气迁移研究

Study on moisture transfer of external insulation system in hot summer and cold winter regions

采用墙体保温系统耐候性测试及湿气迁移动态监测平台研究了蒸压加气混凝土砌体的湿气迁移过程,并通过模拟的方法分析了蒸压加气混凝土为主墙体的外保温系统在夏热冬冷地区的湿气迁移特性。结果表明:蒸压加气混凝土砌块的平衡吸湿率随相对湿度的增大逐渐增大。蒸压加气混凝土砌体具有良好的传湿性能,在约14 d时湿气迁移基本稳定。在传湿模拟中,蒸压加气混凝土墙体外保温系统不会出现冷凝,而在相对湿度比较高的部位可能因毛细凝结而出现液态水。为避免这一问题,提出了采用蒸压加气混凝土作为主墙体的外保温系统在特殊部位的水蒸气传输控制技术,有利于提升系统的功能性及耐久性。

The moisture absorption process of aerated concrete block is studied firstly,then the moisture migration process of aerated concrete masonry is studied by using the platform of weather resistance test and moisture migration dynamic monitoring of the external insulation system,and then the moisture migration characteristics of the external insulation system with aerated concrete as the main wall in hot summer and cold winter regions are studied by means of simulation.The results show that the equilibrium moisture absorption rate of aerated concrete block increases with the increase of relative humidity.Aerated concrete masonry has good moisture transfer performance and the moisture migration is basically stable at about 14 days.In the simulation of moisture transfer in this paper,there is no condensation in the external insulation system of aerated concrete wall.However,liquid water may appear in the part with high relative humidity due to capillary condensation.In order to avoid this problem,this paper puts forward the control technology of using aerated concrete as the external insulation system of the main wall to transfer water vapor smoothly in special parts,which is conducive to improving the functionality and durability of the system.