ATB柔性基层与半刚性基层的层间抗剪规律

以ATB-25沥青混合料与水泥稳定碎石成型复合试件,控制复合试件层间沥青和碎石用量,采用自主研发的剪切仪进行抗剪强度试验,分析影响层间抗剪强度的因素及变化规律。通过设置试验温度、碎石和沥青用量等参数,制定不同的试验方案进行试验。试验结果表明:对层间抗剪强度影响最大的因素是温度,从5 ℃上升到35 ℃时最大剪应力从1.36 MPa下降到0.16 MPa,其次是沥青用量；碎石用量影响最小,而且不同温度下沥青和碎石的最佳用量也不同。在实际工程中,在考虑沥青和碎石的用量时,应考虑工程所在的地区,高温地区沥青的用量应比低温地区稍低一些,同时严格控制碎石用量,提高层间联结质量,明确层间抗剪强度与层间联接各因素的规律。

The interlaminar shear rule between flexible base and semi-rigid base

ATB-25 asphalt mixture and cement stabilized macadam were taken to shape composite specimen, the amount of asphalt and chip in the composite specimen layer was controlled. The develop shear apparatus was used to carry out shear strength test, the influence factors and change rules of interlaminar shear strength were analyzed based on the test results. Different test schemes were worked out by setting up the test temperature and the amount of chip and asphalt. The test results showed that the temperature was the most influencing factor on the shear strength of the layer, when the test temperature increased from 5 ℃ to 35 ℃, the maximum shear stress decreased from 1.36 MPa to 0.16 MPa. The second influencing factor was the amount of asphalt, the aggregate content had the least influence, and the optimum asphalt content was different due to the different temperature. Therefore, in practical engineering, the amount of asphalt and gravel should be considered in combination with the location. The asphalt content in high temperature area should be slightly less than in the low temperature area. The aggregate content should be strictly controlled to improve the quality of interlayer connection and define the laws of interlaminar shear strength and connection.