Investigation of Porous Asphalt Surface Parameters Used in Traditional Texture Passages

Permeable pavement, including porous asphalt, is one of the best management practices in urban stormwater control, which is an effective way to protect brick and mud from rain runoff. The aim of this study is to investigate the relation between parameters related to the surface texture of porous asphalt with evaporation and permeability as two key properties of porous asphalt. For this purpose, laboratory samples were first made. By performing permeability and evaporation measurement tests in an innovative way, the amount of permeability and evaporation of porous asphalt with different gradations was determined. Then, with image processing and English pendulum device, parameters related to the surface texture of the samples such as surface porosity, fracture of surface aggregates and slip resistance were measured. Their effect on evaporation and permeability was investigated. The results of this study indicate that with finer gradation, the amount of surface porosity and angle and visible fractures of aggregates in the sample surface is reduced by about 27% and 48%, respectively. Also, the results of slip resistance test show that in dry state, the friction decreases by about 11% as the gradation becomes larger and in the wet state, the larger the texture, the slip resistance is about 32% higher. Based on the results presented in this study, the parameters related to the surface texture of the sample have a significant relationship with the rate of evaporation and permeability of porous asphalt; which is presented in this research. With the relationships presented in this study, it is possible to estimate the permeability and evaporation of porous asphalt by measuring the parameters related to the surface texture, which are relatively easier and faster to measure.