均匀化法二相模型在轻集料混凝土水汽传输中的应用研究

Application of two-phase homogenization model in water vapor transport of lightw eight aggregate concrete

轻集料混凝土由于具有自重轻、保温隔热和抗震性能好等优点而越来越多的应用到工业与民用建筑及其他工程中。相对于普通混凝土,轻骨料混凝土相内部的孔隙率更多,孔隙的存在为内部传湿提供了传输通道,但目前有关轻骨料混凝土湿度扩散的研究并不多。细观力学可建立材料细观结构和宏观性能的联系,本课题将通过引入细观力学均匀化二相模型结合传质理论来研究轻集料混凝土的水汽传输过程。一方面通过该模型,对轻集料混凝土内部各组成相的与整体的湿度扩散系数之间的关系进行理论分析,从而预测不同配合比的混凝土的湿度扩散能力;另一方面通过传质理论和试验数据,构建轻集料混凝土湿度扩散本构关系,且结合有限元进行数值模拟,分析了轻集料混凝土在不同环境下的水汽传输过程。

Lightweight aggregate concrete （ LWAC ） are more and more applied to industrial and civil buildings and other projects because of its light weight, good thermal insulation and anti-seismic performance.Compared to the ordinary concrete, LWAC contain more inside pores,the existence of pores provides a transmission channel for moisture transfer,but at present,there is not much research on the moisture diffusion of LWAC.The relationship between microstmcture and macroscopic properties of materials can be established by mesomechanics.It study the water vapor transport process of LWAC by introducing the two-phases homogenization model combined with mass transfer.On the one hand,the model is used to theoretically analyze the relationship between the whole concrete＇ s diffusion coefficient and each component＇s diffusion coefficient in LWAC, thus predict the moisture diffusivity of concrete with different ratios.On the other hand, through the mass transfer theory and experimental data, the constitutive relationship of moisture diffusion of lightweight aggregate concrete was established, and the finite element method was used to simulate the water vapor transport process of LWAC under different environment.