FBG技术监测分析机场跑道沥青加铺层反射裂缝扩展过程

Monitoring and analyzing the process of reflective crack propagation in theairport runway asphalt overlay based on FBG technology

反射裂缝是导致机场跑道加铺层失效的主要病害之一。为分析机场水泥跑道沥青加铺层反射裂缝扩展过程,本文基于光纤布拉格光栅(FBG,fiber Bragg grating)传感技术,提出了可用于实时监测机场水泥跑道沥青加铺层反射裂缝扩展过程的柔性FBG传感器封装方法,并对研发的FBG传感器进行了标定。基于室内组合梁试验,分析了机场水泥跑道沥青加铺层复合结构反射裂缝扩展过程,包括微裂纹萌生与积累、反射裂缝扩展、反射裂缝贯通3个阶段。在反射裂缝扩展初期,FBG传感器中心波长增长速率相对较小;随着反射裂缝逐渐扩展,FBG传感器中心波长迅速增大。结果表明,柔性FBG传感器全部存活且性能完整,验证了其在实时监测机场水泥跑道沥青加铺层反射裂缝扩展过程中的可行性。

Reflective crack is a major distress contributing to the failure of airport runway overlay.To analyze the process of reflective crack propagation in asphalt overlays of airport cement runway,this study proposed a flexible fiber Bragg grating(FBG)sensor packaging method that can be used for real-time monitoring of reflective crack propagation process in asphalt overlay of airport cement runway based on FBG sensing technology,and the developed FBG sensor has been calibrated.Through indoor composite beam tests,the reflective crack propagation process in asphalt overlay composite structure of airport cement runway was analyzed,including three stages of initiation and accumulation of micro cracks,propagation of reflective cracks and complete breakthrough of reflective cracks.During the initial stages of reflective crack propagation,the FBG sensors exhibited a relatively small increase rate in central wavelength.As the reflective cracks gradually extended,the central wavelength of the FBG sensors increased rapidly.Results demonstrated that all of the flexible FBG sensors survived and maintained their integrity,validating the feasibility of real-time monitoring of reflective crack propagation process in asphalt overlay of airport cement runway.