基于沥青膜精确控制的沥青混合料可溶盐侵蚀宏-细观损伤行为研究

In coastal regions, the durability of asphalt pavement is adversely affected by the soluble salts at large. The current state-of-the-art shows that it is difficult to grasp the essence of soluble salt erosion in asphalt mixture which, to a great extent, is due to a lack of understandings of microstructural damage at bitumen-aggregate interface and the macroscopic mechanical degradation of bulk mixture. In this research, an innovative experimental setup which, accurately controls the bitumen film thickness during bitumen-aggregate sample preparation, is proposed and, based on which, a method for evaluating interface adhesion of bitumen-aggregate specimens under soluble salt erosion is developed. Besides, the following tasks are further inquired: i) evaluation of the adhesion of bitumen-aggregate interface under different erosion conditions; ii) development of an analysis framework which can systematically evaluate bitumen-aggregate interface damage under salt erosion; iii) Based on outcomes from i) & ii), the mechanism of bitumen-aggregate interface damage is further unveiled; iv) Investigation of the effects of soluble salt on the macroscopic mechanical properties of different asphalt mixtures; v) development of an analytical method to correlate meso-interface damage response with macroscopic mechanical degradation of bulk mixture under soluble salt erosion and, based on which, a unified method for diagnosing and amending soluble salt erosion in asphalt is determined. The success of this research would provide a theoretical basis for the selection and optimization of road materials suitable for coastal areas and, accordingly, the premature distresses and long term maintenances of pavement are minimized. In this sense, the research has huge practical significance and great value of application.

可溶盐侵蚀是影响滨海地区沥青路面服役寿命的重要原因，由于可溶盐侵蚀下沥青混合料的微细观损伤机理及其引发的宏观力学性能衰变规律不清，导致无法准确揭示可溶盐侵蚀的本质特征。本课题创新性的提出了一种沥青膜厚度精确控制的沥青-集料试件制备方法与界面力学特性测试方法；通过不同侵蚀工况下沥青-集料界面黏结强度的测试，结合界面形貌与可溶盐迁移规律的微细观分析，建立基于力学性能衰减与微细观界面演变的沥青-集料界面损伤分析方法，揭示沥青-集料界面可溶盐损伤机理；研究可溶盐对沥青混合料宏观力学性能的影响，分析沥青-集料界面损伤规律与沥青混合料力学性能衰减规律的内在关系，形成沥青混合料宏-细观性能衰变相结合的可溶盐侵蚀评价体系，并总结出沥青混合料抗可溶盐侵蚀的关键控制因素与合理技术参数。本研究将为滨海地区道路工程材料优选与改性提供科学依据，对滨海可溶盐环境下沥青路面病害预防与维护具有重要的现实意义和推广价值。

可溶盐侵蚀是影响滨海地区沥青路面服役寿命的重要原因，由于可溶盐侵蚀下沥青混合料的微细观损伤机理及其引发的宏观力学性能衰变规律不清，导致无法准确揭示可溶盐侵蚀的本质特征。依据国家自然科学基金申请书中的相关研究规划，项目执行期间研究团队分别对沥青胶浆-集料界面细观力学性能定量测试方法、可溶盐侵蚀下沥青胶浆-集料界面损伤演变规律、沥青混合料抗可溶盐侵蚀控制方法与设计参数等内容展开了深入研究，具体如下：.（1）建立了基于沥青膜厚度精确控制的沥青-集料界面细观力学分析方法，实现了对沥青-集料界面细观力学性能的定量表征。.（2）研究了不同工况下沥青胶浆-集料界面黏结强度与破坏界面的演变规律，揭示了沥青-集料界面可溶盐损伤机理。.（3）采用抗剥落剂对界面进行改性，研究沥青混合料路用性能，提出沥青混合料抗可溶盐侵蚀关键控制因素与材料处理措施。.（4）依托本项目发表学术论文10篇，其中8篇SCI论文，1篇EI论文，1篇中文核心论文；授权国家发明专利1项；获省部级奖励二项，其中一项本人排序第1，另一项为省部级一等奖，本人排序第4；培养3名硕士研究生，其中2名已毕业，1名在读。