粒料柔性基层沥青路面层间细观剪切失效行为及其宏观评价实现

To compensate for the defect of test detection and forecast evaluation of asphalt pavement granular base interlamination stability are difficult to achieve, research idea is different from focusing on mechanical properties of asphalt pavement single structure layer or mechanical properties of a certain scales. "Asphalt layer- tack coat - granular base" structure is represented by the "viscoelastic - cohesion - particles flow "model. Interlaminar coupling mesoscopic mechanics model is builted by utilizing the finite element and development docking technology, interlaminar interface complex work mechanism is explained. Progressive damage analysis method is used to reappear shear cracking evolution process and reveal shear failure behavior. The influence rule of mesoscopic factors on interlamination shear property is analyzed deeply, and mesoscopic shear strength prediction model is built. Aiming at difficult molding and difficult demould characteristics of granular base, composite rut sample mould, test device and method are self-designed for no-demould composite material structure. Combined with equivalent transformation relationship between macro-micro parameters, interlamination mesoscopic prediction model mentioned above is replaced by interlamination macroscopic shear strength evalution model which is verified and built by macroscopic tests. The purposes of interlaminar shear property mesoscopic accurately simulating and macro estimation-evaluation are realized at the same time. Research ideas and results enrich interlamination stability analysis theory and computational methods for composite material structure, meanwhile provide scientific basis for flexible base asphalt pavement structure design, construction control, detection evaluation of asphalt pavement granular base, and promote application of flexible base.

为弥补粒料柔性基层沥青路面层间稳定性试验检测、预估评价难以实现的缺失，不同于关注沥青路面单结构层及某一尺度下力学性能的研究思路，采用“粘弹性—内聚力—颗粒流”模型表征“沥青层—粘结层—粒料基层”结构，利用有限元及开发对接技术构建此复合材料结构层间耦合细观力学模型，描述层间界面复杂工作机制；运用逐渐损伤方法再现层间剪切开裂演化过程和揭示剪切失效行为，深入分析细观因素对层间剪切性能的影响规律，建立细观剪切强度预估模型；针对粒料基层成型难脱模难的特性，自行设计不脱模复合材料结构试验装置和方法，结合宏细观参数间等效转换关系，试验验证和建立层间宏观剪切强度评价模型替代上述层间细观预估模型的新思路，同时实现细观精确模拟预测、宏观估算评价层间稳定性能的目的。研究思路和成果丰富了复合材料结构层间稳定性分析理论和计算方法，同时为柔性基层沥青路面结构设计、施工控制、检测评价提供科学依据，推动柔性基层的应用。

为解决粒料柔性基层沥青路面层间稳定性测试、预估、评价难的问题，探索粒料基层与沥青面层之间的层间剪切行为和失效机理，对提高路面整体结构稳定性至关重要。从粒料柔性基层与沥青路面层间复杂界面工作机制出发，采用Monte Carlo方法、Python编程语言和ABAQUS有限元模块，建立了由“粘弹性模型—内聚力模型—颗粒流有限元（随机骨料）模型”表征“沥青面层—粘结层—粒料基层”的耦合细观力学模型。采用逐渐损伤分析方法，再现层间剪切开裂演化过程和揭示剪切失效行为，得到了粒料基层材料类型、竖向压力、水平剪切速度、模型尺寸、粘层油类型等细观因素对层间剪切性能的影响规律。针对粒料基层成型难脱模难的特性，自行设计不脱模复合材料结构试验装置和方法，试验研究确定了粘层油类型、竖向压力、粒料基层级配类型、碾压次数等宏观因素对层间剪切性能的影响规律。结合宏细观参数间等效转换关系，提出了细观剪切强度预估模型和宏观剪切强度预估模型及评价方法。理论研究结果表明，模型尺寸、粘层油类型、竖向压力对层间剪切力峰值影响很大，其他细观因素对其影响很小；模型尺寸越大，粘层油的粘度越高，竖向压力越大，水平剪切速度越大，层间剪切力峰值越大。试验结果表明，层间剪切强度随竖向压力呈线性增长关系，沥青面层的碾压次数越大，线性增长率越大；沥青面层的碾压次数越多，剪切强度越大，但增长速率减弱；间断型粒料基层比连续型粒料基层对碾压次数的敏感性大，层间剪切强度小于连续型。研究成果丰富了复合材料结构层间稳定性分析理论和计算方法，能促进科学理解粒料基层散粒特性和沥青路面层间接触的复杂性和协同性，促进粒料柔性基层层间试验检测和预估新方法的发展，为粒料柔性基层沥青路面层间复合结构设计提供重要科学依据，为层间处治措施效果和工程实践提供评价分析方法，具有重要的科学意义和推广应用价值。