复合式路面层间界面剪切滑移特性

依托南大梁高速公路复合式路面试验段, 测试了不同糙化界面的露骨率和构造深度, 并钻取芯样进行45°剪切试验。结合45°剪切试验测试结果与层间剪切过程力学特性, 将层间剪变特性曲线划分为弹性阶段、破坏阶段、剪切强度衰减阶段和残余阶段, 采用界面构造深度、剪切强度峰值、剪切强度峰值对应层间相对滑动位移和残余剪切强度等指标评价层间剪变特性, 分析了界面糙化方式、防水黏结材料类型和用量、温度和加载速率对复合式路面层间剪变特性的影响。测试结果表明: 凿毛界面构造深度(1.17mm) 大于喷砂界面构造深度(0.37mm), 结合不同糙化界面下剪切过程的层间力学特性差异, 凿毛界面较喷砂界面所成型复合试件具有更优的抗剪性能; 防水黏结材料相同时, 凿毛界面层间剪切强度峰值对应层间相对滑动位移(0.19~0.79mm) 较喷砂界面(0.16~0.33mm) 更大, 且防水黏结材料对残余剪切强度和剪切强度峰值的影响大于层间剪切强度峰值对应层间相对滑动位移的影响; 整体而言, 温度对层间剪变特性影响显著, 5℃时层间剪切强度峰值为40℃时的7.0~10.0倍, 测试条件对层间剪切强度影响较大, 50mm·min-1加载速率时测试层间剪切强度峰值为5mm·min-1加载速率时的1.9~3.5倍。可见, 凿毛糙化方式更有助于提高复合式路面层间剪切强度, 且复合式路面层间剪变特性需采用多指标予以评价。 

Interlaminar interface shear slip characteristics of composite pavement

Based on the composite pavement test section of Nandaliang Expressway, the exposed bone ratios and texture depths of different roughened interfaces were tested, and 45°shear tests were carried out with core samples drilling in the field test section. Combined with 45°shear test results and the mechanical properties in the interlaminar shear process, the interlaminar shear and deformation curve was divided into four stages: elastic stage, failure stage, shear strength reduction phase, and residual phase. The interlaminar shear and deformation behavior was evaluated by using the texture depth, peak shear strength, relative interlaminar slip displacement corresponding to the peak shear strength, and residual shear strength. The effects of interface roughness mode, types and amounts of waterproof cohesive materials, temperature, and loading rates on the interlaminar shear and deformation characteristics of composite pavement wereanalyzed. Test result shows that the texture depth of the chiseling interface (1.17 mm) is greater than that of the sand-blasting interface (0.37 mm). Combined with the interlaminar mechanical property differences of different roughened interfaces in the shearing process, the composite specimen formed at the chiseling interface has better shear resistance performance than that formed at the sand-blasting interface. The relative interlaminar sliding displacement corresponding to the peak shear strength of the chiseling interface (0.19-0.79 mm) is larger than that of the sandblasting interface (0.16-0.33 mm) with the same waterproof cohesive materials. Moreover, the effect of waterproof cohesive materials on the peak shear strength and residual shear strength is greater than that of the interlaminar relative slip displacement corresponding to the peak shear strength. As a whole, the effect of temperature on interlaminar shear and deformation characteristics is remarkable, and the peak shear strength at 5℃is 7.0-10.0 times of the value at40℃. The test conditions have a great influence on the interlaminar shear strength, and the interlaminar peak shear strength measured at 50 mm·min-1 loading rate is 1.9-3.5 times of the value measured at 5 mm·min-1 loading rate. Thus, the chiseling roughened method is more helpful to improve the interlaminar shear strength of the composite pavement, and the multiindex should be used to evaluate the interlaminar shear and deformation characteristics of the composite pavement.