ABSTRACT

This research was undertaken to study the effects of grid opening size and tack coat type on both the shear strength and shear fatigue resistance at the interface of fibreglass grid-reinforced asphalt concrete specimens and, more importantly, to correlate these effects with the interfacial fatigue performance under four-point bending beam fatigue loading. The specimens were fabricated using a 12.5-mm nominal maximum aggregate size surface mixture. Two types of fibreglass grid, differing only in the grid opening size, and two tack coats, a PG 64-22 asphalt binder and a slow-setting anionic asphalt emulsion with low viscosity, were used to reinforce the specimen interfaces. The digital image correlation technique was utilised to measure displacements, strains, and crack lengths. The test results indicate that a strong tack coat and a grid with large openings can potentially improve the shear resistance of a grid-reinforced interface but the effects of these two parameters might differ under monotonic and cyclic loading conditions. The cyclic shear, beam fatigue, and monotonic displacement-controlled shear test results suggest that the grid opening size plays a key role in the interface shear fatigue performance, however tack coat quality plays a more important role on the interface shear strength of the specimens.

摘要

本研究旨在研究网格开口尺寸和粘性涂层类型对玻璃纤维网格增强沥青混凝土试样界面处的剪切强度和抗剪切疲劳性的影响，更重要的是，将这些影响与界面疲劳性能相关联四点弯曲梁疲劳载荷下。使用 12.5 毫米标称最大骨料尺寸的表面混合物制造样品。两种类型的玻璃纤维网格（仅网格开口尺寸不同）和两种粘性涂层（一种 PG 64-22 沥青粘合剂和一种低粘度的慢凝阴离子沥青乳液）用于加强试样界面。数字图像相关技术用于测量位移、应变和裂纹长度。测试结果表明，强粘性涂层和具有大开口的网格可以潜在地提高网格增强界面的抗剪切性，但这两个参数的影响在单调和循环加载条件下可能不同。循环剪切、梁疲劳和单调位移控制剪切试验结果表明，网格开口尺寸在界面剪切疲劳性能中起关键作用，而粘层质量对试件界面剪切强度的影响更为重要。