Dynamic Variation Characteristics and Influencing Factors of Evaporation Intensity of Permeable Pavement

ZHANG Jingyi1, QIN Huapeng1,†, ZHAI Yanyun2

1. Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055; 2. Shenzhen Eco Vista Tech. Co. Ltd.,

Shenzhen 518055; †Corresponding author, E-mail: qinhp@pkusz.edu.cn Abstract A typical evaporation simulation platform for permeable concrete pavement is designed and built. The variation process of moisture content, evaporation, moisture absorption, surface temperature and the weather conditions in Shenzhen city are continuously monitored and recorded under the natural environment conditions, which are carried out to analyze the variations in the evaporation intensity of the pavement, and to explore the main influencing factors. The results show that, in the rainy season, the rainfall can significantly increase the evaporation intensity of permeable concrete pavement, but its influence is limited, and this enhancement effect will gradually weaken to a lower level in eight hours. With the variation of time and rainfall conditions, the influence degree of many factors is different in different periods. During the daytime, the evaporation intensity of permeable concrete pavement is positively correlated with the solar radiation and moisture content. During the nighttime, the evaporation intensity is close to zero when there is no rain in the early stage, which is only correlated with the change of wind speed. While after the rainfall, the higher air temperature, greater wind speed, higher moisture content and surface temperature of the pavement will increase the evaporation intensity, however the increase of the relative humidity will lead to the decrease of the evaporation. In the dry season, permeable concrete pavement, as a porous medium, can increase moisture content and promote evaporation intensity by the moisture absorption on the surface of the pavement, which is an important factor affecting the dynamic variations of the evaporation intensity. Key words permeable pavement; evaporation intensity; rainfall; moisture absorption