Multi-scale analysis of moisture diffusion and distribution in different types of asphalt mixtures

Abstract

ABSTRACT Owing to the existence of high hydrodynamic pressure in heavy traffic conditions, moisture will diffuse quickly into the asphalt mixtures, which will induce the adhesive failure of asphalt mixtures and shorten the service life of asphalt pavement. This research aims at solving the problems of moisture diffusion and distribution of asphalt mixtures, especially in heavy traffic conditions. The moisture diffusion paths, moisture distribution and the susceptible areas of moisture damage were investigated by molecular dynamics simulations, numerical simulation and experiments. The slope of fatigue lifetime function of OGFC-13 (1.0 atm), OGFC-13 (1.5 atm) and OGFC-13 (2.0 atm) is −4.23, −4.22 and −4.20, respectively. It shows that hydrodynamic pressure affects the fatigue lifetime and reduces the durability of asphalt mixtures. The moisture diffusion path is three-dimensional tortuous curves, and moisture distribution is related to air voids or mixtures types of asphalt mixtures, and the moisture diffusion coefficient of z-direction is the biggest in heavy traffic condition. Moreover, the length of moisture diffusion paths is more than the thicknesses of the asphalt mixtures.