Optical Fiber Sensor Based In-Field Structural Performance Monitoring of Multilayered Asphalt Pavement

The durability, robustness, and long-term stability of optical-fiber-based sensors applied to practical engineering have always been challenging problems. Refer to the sensors embedded in asphalt pavements, the situation becomes serious and feasible sensors with enhanced function are in high demand. Therefore, an improved design to configure the quasi-distributed and distributed optical fiber sensors and FBG-based point sensors for monitoring the three-dimensional information of multilayered asphalt pavements is needed. The in-field data declare that the transversal, longitudinal, and vertical deformations of the tested urban asphalt pavement are mainly affected by temperature. The M-shape strain profile induced by heavy vehicles can decrease to the regular state in approximately 30 min after unloading. The tested asphalt pavement presents good structural performance to bear the tensile strain and permanent deformation. The high survival ratio and the good robustness of the proposed sensors against the harsh construction and operation environment validate the feasibility and reliability for the long-term monitoring. Improved design proposals on the construction scheme of asphalt pavement are also addressed to control the strain of the established asphalt concrete course in relatively low level.