Wetting and drying in hydrophobic, macroporous asphalt structures

摘要: Abstract Wetting and drying of a hydrophobic, macroporous medium like porous asphalt (PA) are investigated in this study under different environmental loadings. Three types asphalt, PA4, PA8 PA11, with pore size distributions, used to produce specimens that sealed on all sides except at the top surface, wetted by discrete water droplets or pouring from top. The wet subjected surface airflow, low (1 m/s) high (3 m/s) wind speeds, heat UV lamp. Gravity-driven imbibition impinging is observed only PA11 due presence large pores diameters between 2 6 mm. However, patterns three PA similar i.e. even after 3.5 h forced convective non-isothermal drying, evaporates near surface. hydrophobicity solid matrix limits influence liquid transport process. Consequently, dominant mechanism found evaporation free islands within specimen, followed vapor diffusion its subsequent convection airflow. Therefore, speeds lead faster if moisture concentrated specimen. In comparison previous experiment, it seen specimens, gravity-driven drainage most important source fast removal has much shorter time-scale than drying.