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低温开裂一直是寒冷地区沥青路面的主要病害之一。利用研制的沥青混合料降温收缩断裂试验仪,在不同降温速率和初始温度下,进行了不同沥青及其用量、集料及其级配组成的改性沥青混合料的降温收缩断裂试验,以断裂强度、断裂温度、转折点温度和温度应力曲线斜率的绝对值为指标,对比分析了不同因素的影响。结果表明:改性沥青标号、沥青用量、矿料级配组成、降温速率和初始温度对沥青混合料降温收缩特性的影响较大;采用标号较高的改性沥青,沥青用量为马歇尔方法确定的最佳沥青用量,有利于提高沥青混合料抵抗降温收缩断裂的能力;骨架密实结构的沥青混合料的抗降温收缩断裂性能更好;在初始温度较高的快速降温下,沥青路面的开裂几率较大。
Low-temperature cracking has been one of the major diseases of asphalt pavement in cold regions. Using the developed asphalt mixture cooling shrinkage tester, at different cooling rates and initial temperature, different asphalt and its dosage, aggregate and its gradation composition of modified asphalt mixture cooling shrinkage fracture test to fracture strength , The rupture temperature, the turning point temperature and the absolute value of the slope of the temperature stress curve as an index, comparatively analyzed the influence of different factors. The results show that the modified asphalt grade, the amount of asphalt, the composition of ore grade, the cooling rate and the initial temperature greatly affect the cooling and shrinkage characteristics of asphalt mixture. The modified asphalt marked with Marshall method The best asphalt dosage is conducive to improving the ability of asphalt mixture to resist the shrinkage and rupture of cooling; the asphalt mixture with skeleton compact structure has better anti-temperature and shrinkage rupture performance; at the initial rapid cooling, the cracking probability of asphalt pavement is more Big.