不同湿温条件下路面材料热物性参数研究

Study on Thermal Property Parameters of Pavement Materials Under Different Humidity and Temperature Conditions

基于设在大同、广州气象站内的路面结构温度试验区的实测路面温度与相对应的气象数据,利用有限差分法和模式搜索法,研究不同温湿度条件下路面材料的热物性参数变化规律,讨论一次持续降雨对路面温度场的影响。结果表明,水泥混凝土和沥青混合料面层的导热系数在-10~30℃内可视为常值,水泥稳定碎石基层和级配碎石垫层的导热系数随温度降低而减小,尤其在冬季路面结冰情况下可减小40%以上;一次持续降雨对路面温度场的影响时长为5~30 h不等,降雨浸湿路表可使路面面层上部约60~120 mm的导热系数增大10%~60%,使温度相比晴天干燥传热状态下降低0.1~5℃;路面材料导温系数的影响因素更多且更为复杂而呈现随机波动现象,其中,温湿引起波动在20%以内且对传热效率的影响不大,一般可忽略。

Based on the measured pavement temperatures and the corresponding meteorological data in the pavement structure temperature test areas located in the meteorological stations of Datong and Guangzhou,the variation patterns of the thermal physical parameters of pavement materials under different temperature and humidity conditions were investigated using the finite difference method and the mode search method,and the effects of one continuous rainfall on the temperature field of the pavement were discussed.The results show that the thermal conductivity of cement concrete and asphalt mixture surface layers can be regarded as constant within the range of -10~30℃,while the thermal conductivity of cement-stabilized gravel base layer and graded gravel bedding layer decreases with the reduction of temperature,especially in winter when the pavement is frozen,which can be reduced by more than 40%;the effect of one continuous rainfall on the temperature field of the pavement varies from 5 to 30 h,and the rainfall soaking the road surface can cause the thermal conductivity of the upper part of the pavement,about 60~120 mm of the pavement surface,increasing by 10%~60%,which lowers the temperature by 0.1~5℃ compared to the dry heat transfer state on a sunny day;the influence factors of the temperature conductivity of the pavement are more complex and show random fluctuations,among which,the temperature and humidity cause fluctuations within 20%and have little influence on the heat transfer efficiency,which can generally be ignored.