无缝机场道面用高延性水泥基材料(ECC)的自愈合行为与机理研究

Under the combined effects of mechanical and environmental loading, the airfield pavement is prone to appear the distresses of cracking, joints damage, and pavement panels’ vertical move et al., consequently, result in the frequent maintenance during the service life. Based on the current situation, this proposal attempts to apply the Engineered Cementitious Composites (ECC) as the airfield pavement material due to its high ductility and self-healing capacity. The use of ECC is expected to control the cracks’ propagation and achieve the jointless function of airfield pavement. While traditional methods typically consist of repairing by various materials after the appearance of distresses, this approach is fundamentally different from them in that it takes advantage of the high ductility to achieve jointless function on airfield pavement, thus avoiding the distresses caused by the joints damage. Besides that, it heals its damage by the secondary hydration of fly ash or the recrystallization of calcium carbonate over the micro-crack damage sites of ECC. Therefore, the repair activity is automatic and at very low cost, resulting in long-lasting service life. This proposal puts special emphasize on the study of ECC’s self-healing behavior and mechanism. Firstly, the mechanism how self-healing phenomena do impact on the mechanical properties’ recovery of ECC is figured out in basis of ECC’s multiple-scales design theory. Considering the real status of cracks in pavement panels’ actual service condition, the self-healing behavior of ECC under loading is revealed afterwards. In final, it attempts to clarify the methods and mechanism to activate ECC’s repeatable self-healing phenomena.

在飞机荷载与环境荷载的长期共同作用下，机场道面易出现裂缝类、接缝类和竖向位移类等病害，从而导致运营阶段需经常性人工维修。鉴于此，本项目提出将具有自愈合功能的高延性ECC材料作为机场道面以控制裂缝发展并实现无缝连接。这与以前对机场道面材料与结构的研究在范式上具有根本的区别：即不是通过事后修补的方法，而是利用ECC的高延性实现机场道面的无缝以避免接缝类病害；并鉴于机场道面处于开裂状态下利用ECC材料微裂缝内的二次反应或碳酸钙的沉淀结晶来使裂缝愈合，减少后期人为的维护工作，大大延长其使用寿命。本项目以机场道面用ECC材料的自愈合行为与机理为科学问题，基于ECC的多尺度设计理论，从多个尺度层面厘清ECC力学行为的自愈合机理；结合使用过程中ECC机场道面上裂缝所处的真实状态，揭示ECC在持载条件下的自愈合行为；针对ECC多次自愈合效果不佳的研究现状，探明ECC多次自愈合现象的激发方法与机理。

在飞机荷载与环境荷载的长期共同作用下，机场道面易出现裂缝类、接缝类和竖向位移类等病害，从而导致运营阶段需经常性人工维修。鉴于此，本项目提出将具有自愈合功能的高延性ECC材料作为机场道面以控制裂缝发展并实现无缝连接。这与以前对机场道面材料与结构的研究在范式上具有根本的区别：即不是通过事后修补的方法，而是利用ECC的高延性实现机场道面的无缝以避免接缝类病害；并鉴于机场道面处于开裂状态下利用ECC材料微裂缝内的二次反应或碳酸钙的沉淀结晶来使裂缝愈合，减少后期人为的维护工作，大大延长其使用寿命。本项目以机场道面用ECC材料的自愈合行为与机理为科学问题，基于微观力学理论，研发了适用于无缝机场道面使用的ECC材料；结合使用过程中ECC的受力状态，揭示了ECC的自愈合行为；基于ECC的多尺度设计理论，从多个尺度层面厘清了ECC力学行为的自愈合机理；揭示了养护环境对ECC自愈合行为的影响机理，为ECC的多次自愈合现象的激发方法提供依据。