[en] Highlights: • Vapor flow regime in fine aggregate mixes reveal the existence of non-Fickian flow. • Determinant of vapor molecules moving from free to bound phase is relative humidity. • Determinant of vapor molecules leaving bound to free phase is asphalt binder. • Time-variable diffusion characteristics show slight dependence on relative humidity. Moisture vapor diffusion resulting from the difference in relative humidity between air and pavement material contributes to moisture damage. Understanding moisture vapor diffusion in asphalt pavement is the first task in the analysis of moisture damage. Analysis was conducted in an automated environmental chamber with a temperature precision of ± 0.5 °C and relative humidity precision of ± 3%. Moisture uptake profiles for fine aggregate mixtures (FAMs) under various environmental conditions (relative humidity and ambient air temperature) and constituent materials (aggregate and asphalt binder) were measured. Preliminary data analysis showed the existence of Non-Fickian diffusion behavior. Therefore, two non-Fickian and one Fickian models were introduced to fit the measured moisture uptake data and determine FAM diffusion characteristics, such as diffusion coefficient, diffused moisture phase, and time-variable diffusion. Based on the variation in FAM diffusion characteristics under various experimental conditions and constituent material combinations, sensitivity analysis was conducted with one-way ANOVA and the determinants of FAM vapor diffusion characteristics were proposed.