严寒地区水泥乳化沥青砂浆的低温性能及疲劳性能试验研究

Experimental Study on the Low Temperature Property and Fatigue Property of Cement-Emulsified Asphalt Mortar Used in Severe Cold Region

运用试验方法,进行严寒地区用水泥乳化沥青砂浆抗冻性、低温力学性能和低温抗裂性的低温性能及疲劳性能研究。结果表明,该种砂浆的抗冻性可达600次以上;随着温度的降低,砂浆的抗压强度、抗折强度逐渐增加,-40℃下砂浆的折压比在0.2以上;砂浆出现裂纹时钢球的压入深度均大于1.2 mm;模拟行车条件下砂浆的受力情况,进行10~40 Hz频率350万次疲劳试验,砂浆的累积变形量均小于0.07 mm。结合试验结果和严寒地区试验段的运营考察,考虑到严寒地区-40℃的极端温度条件和350 km.h-1的运营速度,提出严寒地区水泥乳化沥青砂浆的低温性能指标为-40℃砂浆出现裂纹时钢球的压入深度不小于1.0 mm,低温折压比不小于0.20;疲劳性能指标为12 Hz加载频率下经100万次疲劳试验的砂浆累积变形量不大于0.10 mm。

Proper experimental methods were used to study the low temperature properties,such as the freezing resistance,mechanical properties,crack resistance,and the fatigue properties of cement-emulsified asphalt mortar used in severe cold region.The results show that the freezing resistance of this kind of mortar can reach at least 600 times.Its compressive strength and the bending strength rise gradually along with the decrease of the test temperature.The ratio of bending strength and compressive strength below-40 ℃ is above 0.2.The depth pressed into the mortar by the steel ball is above 1.2 mm when crack occurs in the mortar.The accumulated deformation is less than 0.07 mm after 10～40 Hz frequency 3.5 million times fatigue test to stimulate the working condition of the mortar.According to the test results and the inspection of the mortar used in the experiment zone in severe cold region after traffic operations,considering the severe temperature condition of-40 ℃ in the cold region and 350 km·h-1 operation speed,the indexes of the low temperature property for cement-emulsified asphalt mortar used in severe cold region are suggested.The depth pressed into the mortar by the steel ball at-40 ℃ should be no less than 1.0 mm when crack occurs in the mortar,the ratio of bending strength and compressive strength is no less than 0.2,and the accumulated deformation after 12 Hz loading frequency 1.0 million times stimulated fatigue test is not more than 0.10 mm