Bending strain progression and damage of asphalt beams based on distributed fibre optic sensors
Xuebing Zhang, Luoqing Liu, Zhizhou Zheng, Yang Quan, Zhizhan Chen, Jun Cao, Tianyun Zhang, Xiaonan Xie, Xiaochun Liu, Ping Xiang
Abstract
Under long-term vehicle loading, asphalt pavement surfaces undergo settlement, while the lower layers develop cracks due to the imposed loads. These cracks gradually propagate upwards until they penetrate the surface layer. In extensive transportation environments, many newly constructed roads often develop bottom cracks after a period of use. These cracks can expand gradually under sustained loads and natural conditions, potentially evolving into through cracks, thereby exacerbating damage to the road surface and reducing its lifespan. To enhance the longevity of asphalt pavement, it is crucial to conduct health monitoring to track crack development. This study addresses this issue by using small asphalt beams to simulate damage progression. Static and fatigue loading three-point bending tests were conducted on these asphalt beams. Distributed fibre optic sensors were employed to monitor strain distribution curves during loading, enabling analysis of the failure process of asphalt beams. This approach systematically evaluates deformation capacity, stages of crack development, and load-bearing capacity based on the strain distribution curves. The test results indicate that distributed fibre optic sensors can effectively monitor the strain conditions of asphalt beams. They are also capable of accurately identifying the origins of cracks and tracking their formation and development in real time.