Factors of water vapor diffusion in semi-rigid base

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.