半刚性基层内水气扩散影响因素

Factors of water vapor diffusion in semi-rigid base

摘要:

为从水气角度量化沥青路面水损害提供理论依据,探究半刚性基层内水气扩散的影响因素,通过理论推导确定材料厚度和温度条件这两个主要影响因素,设计试验装置和试验方案,探究材料厚度和温度条件对半刚性基层内水气扩散的影响规律。研究结果表明:半刚性基层内水气扩散与其两侧相对湿度差无关,与温度因素和厚度条件相关；水气扩散通量随着材料厚度增大而逐渐减小,且减小趋势逐渐减缓,而水气扩散系数随着材料厚度增大而增大,且增大趋势逐渐减缓,这说明材料厚度增大会在一定程度上阻碍半刚性基层内的水气扩散；水气扩散通量随着温度增大而增大,且增大趋势逐渐加剧,而水气扩散系数随着温度增大而增大,且增大趋势逐渐加剧,这说明温度增大会为水气扩散提供更多的能量,加剧水气在半刚性基层内的扩散。

Abstract:

To provide a theoretical basis for quantifying the moisture damage of asphalt pavement from the perspective of water vapor and explore the influence factors of water vapor diffusion in semi-rigid bases, the two main influencing factors (material thickness and temperature conditions) were determined through theoretical derivation, and the test device and test plan were designed to explore the influence of material thickness and temperature conditions on water vapor diffusion in semi-rigid bases. Results show that the water vapor diffusion in the semi-rigid base layer had no relation with the relative humidity difference between its two sides, but was related to temperature conditions and material thickness. The water vapor diffusion flux gradually decreased as the material thickness increased, and the decreasing trend gradually slowed down; while the water vapor diffusion coefficient increased as the material thickness increased, and the increasing trend gradually slowed down, which indicates that the increase in material thickness hinders the diffusion of water vapor in the semi-rigid base layer to a certain extent. The water vapor diffusion flux increased with the increase in temperature, and the increasing trend gradually intensified; while the water vapor diffusion coefficient increased with the increase in temperature, and the increasing trend gradually intensified, which indicates that the increase in temperature can provide more energy for the diffusion of water vapor and aggravate the diffusion of water vapor in the semi-rigid base layer.