混凝土气体扩散系数测试方法理论研究

Research on rapid testing method for gas diffusion coefficient of concrete

在研究气体在多孔介质材料中传输机制的基础上,根据相关理论推导了基于压力梯度的混凝土气体有效扩散系数计算公式,提出了通过合理提高压力梯度测试高性能和长龄期混凝土透气性的试验方法,并应用测得的有效扩散系数和气体在直毛细孔中扩散系数的关系模型得到了混凝土孔曲折度因子计算式。

On the basis of studying gas transfers mechanism into porous medium materials, a calculation formula of gas effective diffusion coefficient of concrete based on pressure gradient is deduced according to the relative theory, and a new rapid testing method for gas penetrability of high performance concrete and old concrete with higher pressure gradient is developed. Making use of the relationship model between the gas effective diffusion coefficient of concrete and the gas diffusion coeffident in straight capillary pore, the calculation formula of pore tortuosity factor in concrete is established.