渗透铺装蒸发强度的动态变化规律及影响因素分析

设计并搭建一种典型透水混凝土铺装蒸发模拟实验平台, 在深圳市的气象条件下, 连续观测铺装含水量、蒸发量、吸湿量和表面温度等的变化过程, 分析透水混凝土铺装蒸发强度的动态变化规律及影响因素。结果表明, 在雨季, 降雨可显著地增加透水混凝土铺装的蒸发强度, 但影响的持续时间有限, 8小时内这种增强效应会逐渐减弱至较低水平; 随着昼夜及降雨条件的变化, 各影响因素在不同时期影响程度不同。昼间,透水混凝土铺装的蒸发强度与太阳辐射及铺装含水量正相关, 且当前期有降雨时, 相关性会明显提高。夜间,前期无降雨时蒸发强度接近零, 仅随风速变化有较小的波动; 当前期有降雨时, 气温越高, 风速越大, 铺装含水量及表面温度越高, 蒸发强度也越大, 大气相对湿度增加会导致铺装蒸发强度减小。在旱季, 透水混凝土铺装作为一种多孔介质, 其表面在适当天气条件下发生的吸湿现象将持续补充铺装含水量, 促进蒸发, 是影响蒸发强度的重要因素。

Dynamic Variation Characteristics and Influencing Factorsof Evaporation Intensity of Permeable Pavement

A typical evaporation simulation platform for permeable concrete pavement is designed and built. Thevariation process of moisture content, evaporation, moisture absorption, surface temperature and the weatherconditions 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 maininfluencing factors. The results show that, in the rainy season, the rainfall can significantly increase the evaporationintensity of permeable concrete pavement, but its influence is limited, and this enhancement effect will graduallyweaken to a lower level in eight hours. With the variation of time and rainfall conditions, the influence degree ofmany factors is different in different periods. During the daytime, the evaporation intensity of permeable concretepavement is positively correlated with the solar radiation and moisture content. During the nighttime, theevaporation intensity is close to zero when there is no rain in the early stage, which is only correlated with thechange of wind speed. While after the rainfall, the higher air temperature, greater wind speed, higher moisturecontent and surface temperature of the pavement will increase the evaporation intensity, however the increase ofthe 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 absorptionon the surface of the pavement, which is an important factor affecting the dynamic variations of the evaporationintensity.