ABSTRACT

A proper interface bond between adjacent asphalt concrete layers ensures the layers to act monolithically to withstand traffic and thermal loading. The presence of a weak interface results in delamination, slippage and fatigue cracks thereby affects the pavement performance; hence, requires careful evaluation. The objectives of this investigation are three-fold. The first objective is to develop a test protocol to investigate the damage characteristics of the interface bond. The proposed test applies a 5 Hz cyclic shear load on a double-layered asphalt concrete specimen using a Modified Advanced Shear Tester at 23°C. The second objective is to determine the effect of interlayer shear modulus on the pavement response of typical pavement sections using numerical simulations. The interface material model property used in this study is a set of arbitrary values that lies within the typical range of interlayer shear modulus values observed during cyclic shear tests. The third objective is to propose a failure criterion for shear fatigue testing that is based on the critical tensile strain obtained during pavement response analysis. The test outcomes show that specimens with a tack coat at the interface exhibit a significant increase in shear fatigue life resistance compared to specimens with no tack coat.

摘要

相邻沥青混凝土层之间的适当界面结合可确保各层整体发挥作用以承受交通和热负荷。弱界面的存在会导致分层、滑移和疲劳裂纹，从而影响路面性能；因此，需要仔细评估。本次调查的目的有三个。第一个目标是开发一个测试协议来研究界面结合的损伤特性。建议的测试使用改进的高级剪切测试仪在 23°C 下对双层沥青混凝土试样施加 5 Hz 循环剪切载荷。第二个目标是使用数值模拟确定层间剪切模量对典型路面部分的路面响应的影响。本研究中使用的界面材料模型属性是一组任意值，位于循环剪切试验期间观察到的层间剪切模量值的典型范围内。第三个目标是提出基于路面响应分析过程中获得的临界拉伸应变的剪切疲劳试验的失效标准。测试结果表明，与没有粘性涂层的试样相比，在界面处具有粘性涂层的试样的抗剪切疲劳寿命显着增加。