界面性质对沥青路面层间抗剪强度的影响试验

Mechanical Testing on Interlayer Shear Strength Influenced by Interfacial Property in Asphalt Pavement

为研究层间界面性质对沥青路面层间抗剪强度的影响规律及影响机理,采用"上面层混合料+黏层+下面层混合料"的复合圆柱试件模拟实际路面结构,进行了常温25℃时的4种混合料组合类型和3种黏层材料的复合试件层间抗剪强度试验。研究结果表明:在仅有水平剪力作用下,AC-13与AC-20混合料组合的层间抗剪强度最大,而在水平剪力及竖向压力联合作用下,SMA-13与AC-20混合料组合的层间抗剪强度最大;采用洒铺用量为0.4kg/m2的SBS改性沥青作为黏层材料时层间抗剪强度最大;为提高层间抗剪性能,对上下层混合料而言,应在增大层间有效黏结面积的同时增大界面粗糙程度;对黏层材料而言,在控制其用量的同时应提高材料的黏滞性。研究成果对优化层间黏结设计与施工具有参考价值。

In order to study the influence of interracial property on shear strength between asphalt pavement and how it functions, composite cylindrical specimens are produced in the form of ＂top layer mixture＋bonding layer＋bottom layer mixture＂ to simulate actual pavement construction, then a series of tests containing four types of mixture combination and three kinds of tack coats are taken at 25℃. The result indicates that the interface between AC-13 and AC-20 mixture show maximal shearing strength under the condition of only horizontal shear force, but when it comes to the combination of horizontal shear force together with vertical pressure, the shearing strength of the interface between SMA-13and AC-20 tend to be the maximum; 0.4 kg/m^2 of SBS modified asphalt proved to provide the largest shear strength among all tested tack coats; in order to improve the interlayer shear performance, effective layer bonding area and interface roughness should be increased, so should the viscosity of tack coat while its amount controlled. The result could provide reference for optimizing design and construction of interlayer bonding.