断裂模式对沥青混凝土低温开裂特性的影响规律

Effect of fracture mode on low-temperature cracking characteristics of asphalt concrete

为了研究静载荷作用下加载模式和温度对沥青混凝土抗断裂性能的影响,在不同温度条件下,对裂缝沥青混凝土试件进行了纯Ⅰ型、纯Ⅱ型、混合Ⅰ/Ⅱ型等不同加载模式下的三点断裂试验。通过4种温度(-15℃、-5℃、0℃、10℃)和5种加载模式(纯Ⅰ型、纯Ⅱ型、混合型0.8、混合型0.5、混合型0.2)的断裂试验探究沥青混凝土的抗裂性和裂纹扩展规律。结果表明,加载模式和温度对沥青混凝土的抗裂性及裂纹扩展规律具有显著影响;此外,在某个特定的混合加载模式下,沥青混凝土的抗断裂能力最差,该混合加载模式可以作为评估沥青混凝土裂纹开始扩展的指标。

In order to study the effects of loading mode and temperature on the fracture resistance of asphalt concrete under static load,the crack asphalt concrete specimens were taken three point fracture test at three different loading modes(pure modelⅠ,pure modeⅡ,mixed modeⅠ/Ⅱ)under different temperatures.The crack resistance and crack propagation law of asphalt concrete are investigated by fracture experiment at four kinds of temperature(-15℃,-5℃,0℃,10℃)and five kinds of load model(pure modelⅠ,pure modeⅡ,mixed mode 0.8,mixed mode 0.5,mixed mode 0.2).Results show that the loading mode and the temperature have significant effects on the crack resistance and crack propagation law of asphalt concrete.In addition,the fracture resistance of asphalt concrete under a particular mixed loading mode is the lowest,which can be used as an index to evaluate the crack propagation of asphalt concrete.