基于力学相容性和界面弱化机理的OGFC—下卧层组合结构失效行为研究

This project is based on the widely known problems caused by the failures in the composite structure of OGFC and underlying course, which not only affects the service conditions of the pavement but increases the maintenance cost and reduces its service life. On account of that reason, this study will be conducted on OGFC pavements to understand the development criterion and failure mechanism for the OGFC-underlying course, and the mechanical compatibility between the OGFC and sublayer structure will be investigated through a series of experiments, and the deterioration criteria and failure mechanism of the combined structure will be better understood. With the manners of micro-meso analysis and laboratory experiments, 1) the deterioration characteristics of the performances of OGFC mixtures under complicated service conditions will be explored; 2) the compatibility between the OGFC surface layer and underlying layer will be analyzed, and the influence factors towards their compatibility will be discussed; 3) the development criteria of their compatibility during their service life will also be explored; 4) the deterioration mechanism and damage characteristics of the interface bonding properties will be revealed, considering the effects caused by environmental medias; 5) by considering the potential influence factors in the interface and interface transition zones, the failure mechanisms of the composite structure with OGFC and underlying layer will be revealed through large-scale simulation experiments; 6) at last, based on the material compatibility, deterioration mechanism of interfaces, and the failure mechanism of OGFC and underlying layer composite, the failure behavior of OGFC pavements will be analyzed. The expected findings from the study will be useful for the improvement of design method for OGFC materials and structures, as well as the development of high-performance and long life OGFC pavements.

本课题以目前普遍存在的OGFC路面由于面层与下卧层组合结构失效而引起的使用功能退化、服役寿命缩短、维护费用增加的问题为背景，旨在通过微细观测试和宏观力学试验，在充分了解服役环境对OGFC混合料性能影响的基础上，分析和探讨面层和下卧层组合材料的力学相容性及其影响因素，阐明服役过程中组合材料力学相容性的演变规律；考虑环境介质对结构层间界面的影响，揭示界面黏结性能的弱化机理和损伤特征；通过大尺度的结构模拟试验，并引入界面和界面过渡区的潜在影响因素，揭示OGFC面层和下卧层组合结构在长期荷载作用下的失效机制；最后，结合组合材料的力学相容性、层间界面的黏结弱化机理和组合结构在不同服役条件下的失效状态，对OGFC路面结构的失效行为进行分析与评价，从而更好地认识OGFC路面结构的病害成因及改善方法。该项目研究成果能为完善OGFC路面材料与结构的设计方法，以及开发高性能和长寿命的OGFC路面提供理论支持。

现代路面材料与结构的设计更加注重从环境友好、安全、舒适等角度去为人类提供更好的服务。对于功能型路面，由于OGFC面层与下卧层不同的材料特性和所处的不同服役环境，由层间失效所引起的路面早期病害问题屡见不鲜。目前的功能型路面材料与结构设计仍注重于材料自身的力学性能与结构特性，而忽略了多层材料组合结构的力学相容性与层间状态的影响。鉴于此，本课题开展了基于力学相容性的OGFC—下卧层组合结构界面黏结弱化机理与失效行为研究，在满足OGFC路面使用功能的基础上，分析了OGFC面层和下卧层材料间的力学相容性及其影响因素，揭示了不同环境介质对层间界面的弱化机制，阐明了OGFC-下卧层组合结构的疲劳特性与损伤演变规律，并探讨了不同层间接触状态下OGFC路面结构的力学响应与失效行为。主要研究成果如下：（1）通过斜切试验和小梁弯拉试验分别研究了压-剪应力和弯拉应力作用下不同磨耗层-下卧层组合结构的黏结性能与疲劳特性，揭示了组合结构的损伤开展规律，并对不同路面组合结构的失效行为进行了探讨与分析；（2）阐明了典型环境介质对组合结构层间弱化机制、黏结与接触咬合状态的影响，揭示了组合结构疲劳失效形态受到层间黏结与接触咬合状态的影响规律；（3）通过OGFC-下卧层组合结构Overlay试验，评价了OGFC与下卧层组合结构在反复拉伸作用下的疲劳特性，并考虑了不同环境介质及其作用（黏层油洒布量、层间污染、冻融损伤、水侵蚀等）对层间界面性能的影响效果，并阐明了组合结构的损伤开展规律与疲劳失效形态；（4）建立了OGFC路面结构有限元分析模型，在层间界面处引入基于能量的双线性内聚力模型表征界面黏结损伤失效状态，探讨了不同黏结条件下路面结构的应力响应、损伤开展与失效行为。取得的成果发表论文22篇，SCI收录20篇，国内EI收录期刊1篇，国际会议论文1篇；申请与获授权发明专利5项；培养硕士研究生4人，博士研究生1人。