导电沥青及混合料裂缝局部温度场及愈合效果

Local temperature field and healing level of crack in conductive asphalt and mixture

为探究导电沥青胶浆及混合料裂缝附近区域的导电升温效应,制备了不同配比的导电沥青胶浆及混合料,进行了导电愈合试验,利用红外摄像仪测定了导电沥青胶浆和沥青混合料裂缝周围的温度场。采用图像处理技术定量分析了导电沥青胶浆裂缝愈合水平,同时探讨了沥青混合料的反复愈合性能。结果表明:导电沥青胶浆及混合料温度均随通电时间线性升高,升温速率与材料电阻率呈指数函数关系;导电沥青胶浆及混合料裂缝附近区域温度明显高于其他区域,局部升温明显,局部高温有利于实现裂缝定向愈合;沥青混合料反复愈合水平随断裂次数的增多逐渐降低,愈合温度和通电时间对反复愈合水平具有显著影响;利用愈合前、后电阻率比值可估计导电沥青混合料的愈合效果。

In order to explore the conductive heating characteristics of conductive asphalt and mixture near the crack,conductive asphalt and mixture with different proportions were prepared and the conductive healing test was conducted.An infrared camera was used to measure the temperature field around the crack.Digital image processing technology was used to quantitatively analyze the healing level of conductive asphalt.The repeated healing properties of asphalt mixture were analyzed.Results show that the temperature of conductive asphalt and mixture both linearly increase with the charging time.There is an exponential function relationship between the heating rate and electrical resistivity.The temperature of the area near the crack of conductive asphalt and mixture is notably higher than that of others,and the local temperature rise obviously.The local high temperature is conducive to realize the target healing of cracks.The repeated healing index of asphalt mixture gradually decreases with the increasing of fracture cycles.The healing temperature and electrifying time have significant effects on the healing index.The ratio of resistivity before and after healing can be used to estimate the healing level of conductive asphalt mixture.