Optical fiber sensing technology for full-scale condition monitoring of pavement layers

Abstract

Because of the rapidly increased traffic weight and severe service environment (i.e. temperature and humidity) in recent years, a great number of newly paved pavement structures suffer from premature distresses with different scales and degrees, which significantly affects the structural performance. To reflect the deformation characteristics and identify the random damage of long-span pavements, it is particularly important to develop smart optical fiber sensing technology to monitor the in-situ behaviors, which can provide useful suggestions for the repair and maintenance. Considering the evolution of random damage from microscopic to macroscopic, it can be noted that sensors with fixed gauge lengths cannot perceive the whole-process information of structural damage, and local sensors are not able to satisfy the requirement of full-scale condition monitoring of pavement structures. To overcome those deficiencies, various gauge-length based optical fiber/fiber Bragg grating (OF/FBG) sensing techniques have been developed. Laboratory tests on an 8-m-long cement stabilised gravel base layer embedded with the proposed technique have been implemented. The secondly updated sensors have been further applied to an urban asphalt pavement for on-site testing. Research results prove the measurement efficiency, effectiveness and feasibility of the proposed packaging measure and the selected gauge length, and validates the good performance of the OF/FBG sensing techniques for full-scale condition monitoring of asphalt pavements.