摘要 近年来，我国道路交通量日益增大，轴载质量也显著增大，致使路面经常出现剪切破坏。而沥青混合料在设计过程中并未考虑其抗剪能力，这是路面出现车辙的重要原因之一。本文在分析比较国内外现有的沥青混合料剪切性能试验之后，认为同轴剪切试验方法可以较好的评价沥青混合料的抗剪性能，并对该试验方法进行了进一步的深入研究。 本文首先同轴剪切试验方法的中的沥青混合料试件进行了研究，通过建立三维有限元模型，对同轴剪切试验试件力学响应进行了分析。研究同轴剪切试验试件的尺寸形状参数以及沥青混合料材料性能两方面因素对同轴剪切试验结果和剪切强度参数c值的影响，最优化了沥青混合料试件尺寸设计。并提出了同轴剪切试验剪切强度系数c关于沥青混合料模量E和泊松比p取值公式。 其次，对同轴剪切试验方法的整个流程做了分析，包括同轴剪切试验设备的选择、试件的制备、剪切强度试验过程、试验参数和数据处理。并针对试件制备过程中沥青混合料中空圆柱体钻芯偏差和粘结时环氧树脂厚度不足两种情况对同轴剪切试验结果的影响进行了定量分析并给出了建议的解决方案。 然后，在不同温度条件、不同级配条件、不同沥青条件下进行了沥青混合料同轴剪切抗剪试验，研究了混合料抗剪强度的变化规律。同时采用单轴贯入试验检验同轴剪切试验测定沥青混合料抗剪强度的可靠性，并与前人进行的三轴试验测定沥青混合料抗剪强度进行了对比，认为同轴剪切试验测定的沥青混合料抗剪强度是可靠的，并比较分析了同轴剪切试验与单轴贯入试验的不同。 最后，通过分析同轴剪切试验中沥青混合料的剪切应力应变关系，得到沥青混合料AC-13的剪切应力应变方程，并由此推导得到了沥青混合料AC-13的弹塑性本构方程。同时得到了AC-13与AC-20的剪切破坏包络线。运用沥青混合料抗剪强度指标公式，分析了各种条件下沥青路面所采用的沥青混合料的建议抗剪强度，对几种沥青路面条件提出相应的沥青混合料抗剪强度评价标准。 关键词：混合料抗剪性能；同轴剪切试验：抗剪强度系数；抗剪强度；本构方程；抗剪评价标准。 ABSTRACT In recent years，shear destructions arise 013 the asphalt pavements with the volume of traffic growing greatly and the axial load increasing．The anti-shear strength is not considered in the asphalt mixture’s design process, which is one important reason why the mrs appears in the asphalt pavement．With analysis of the various shear tests methods for asphalt concrete both at home and abroad．Co-axial shear test mechod is believed that can evaluate the shear resistance of asphalt mixture performance well．Then filrthor research iS on the co-axial shear test method for asphalt concrete． Firstly, the mechanism responses on the co-axial test sample are analyzed by three-dimensional finite element analysis method, and the coefficient of shear strength is developed．Then research on the influence on the co-axial shear test bv the sample shapes and the asphalt mixture’s material properties．ne formula of shear strength coefficient by module and Poisson’s ratio is first developed． Secondly, research on the process of the co-axial shear test,including the selection of the equipments，sample preparation，the co-axial shear strength test process，parameters and data processing of the co-axial shear test．In view of the next two situations：coring deviation in the hollow cylinder asphalt mixture in the process of sample preparation and lack of the bonding resin，quantitatively analyze their impact and proposed solutions are developed． Thirdly,the anti—shear strength of asphalt mixture of different temperature, grade and bitumen are researched with co-axial shear test． What’s more, uniaxial penetration test results and triaxial test results confirm that the co-axial shear test results ale reliable． Finally, by analyzing the asphalt mixture’s shear stress．Strain relationship in the co-axial shear test,the shear stress-strain equation of AC-13 is developed．And the shear failure envelope of AC-13 and AC-20 is developed at the same time．With the asphalt mixture shear strength formula,and the co-axial shear test results，the corresponding criteria on the anti—shear performance of asphalt mixes for various asphalt pavements is proposed. Key Words: anti-shear property of mixture; co-axialshear test；shear strength coefficient; shear strength; constitutive equation; shear appraising criteria. |
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