Mu Ke, Gao Zhiwei, Shi Xin, Li Yanwei
State Key Laboratory of Road Engineering Safety and Health in Cold and High-Altitude Regions, CCCC First Highway Consultants Co., LTD, Xi'an 710065, China.
XiZang Key Laboratory of Optical Information Processing and Visualization Technology, XiZang Minzu University, Xianyang 712082, China.
Materials (Basel). 2020 Mar 17;13(6):1351. doi: 10.3390/ma13061351.
Asphalt pavement consists of multiple layers of asphalt with a progressive decrease of nominal maximum aggregate size from the bottom to the top, which can be constructed by the double-decked or the conventional paving method (i.e., layer by layer). Reliable interface strength between the fine- and the coarse-grained layer of asphalt mixture is prerequisite to ensure the serviceability of the asphalt pavement. This study aims to compare the interface behavior of the asphalt pavement constructed by the conventional and the double-decked paving methods through laboratory and trial pavement tests. Laboratory test results show that the interface strength of the specimen prepared by the double-decked paving method is mainly contributed by the interlocking of the coarse- and the fine-grained asphalt mixture, fundamentally different from the conventional paving method, in which the interface strength is mainly provided by the tack coat oil. More importantly, the interface shear strength and the uniaxial tensile strength of specimens prepared by the double-decked paving method are about 1.5-1.8 times larger than that of specimens prepared by the conventional paving method. To verify the applicability of laboratory experimental findings to the practical engineering, a trial road was paved in situ using both double-decked and conventional paving methods. Cored specimens were collected from the trial road and their interface strengths are tested. Comparisons of the interface strength obtained from cored specimens further prove that the asphalt pavement constructed by the double-decked paving method has larger interface strength than that of the asphalt pavement constructed by the conventional paving method.
沥青路面由多层沥青组成，其公称最大集料尺寸从底部到顶部逐渐减小，可采用双层或传统摊铺方法（即逐层摊铺）进行施工。沥青混合料细粒层和粗粒层之间可靠的界面强度是确保沥青路面使用性能的前提条件。本研究旨在通过室内试验和试验路测试，比较采用传统摊铺方法和双层摊铺方法施工的沥青路面的界面行为。室内试验结果表明，双层摊铺法制备的试件的界面强度主要由粗粒和细粒沥青混合料的嵌锁作用贡献，这与传统摊铺方法有根本不同，传统摊铺方法中界面强度主要由粘结油提供。更重要的是，双层摊铺法制备的试件的界面抗剪强度和单轴抗拉强度比传统摊铺法制备的试件大约大1.5 - 1.8倍。为验证室内试验结果在实际工程中的适用性，采用双层和传统摊铺方法现场铺筑了一条试验路。从试验路取芯样并测试其界面强度。对芯样获得的界面强度进行比较进一步证明，双层摊铺法施工的沥青路面比传统摊铺法施工的沥青路面具有更大的界面强度。
