In-site health monitoring of cement concrete pavements based on optical fiber sensing technology

Premature stress of cement concrete pavements is the coupled action of construction technique, structural material and environmental action. It is quite difficult to accurately get the actual stress distribution merely based on the theoretical or simulation analysis. Therefore, in-situ health monitoring is particularly significant to obtain the stress or strain information for the assessment on structural performance of cement concrete pavements. To contribute this topic, different kinds of FBG based sensors have been specially designed to measure the temperature, pressure and deformation in cement concrete pavements. A relatively long-term monitoring has been conducted to collect the effective data after the solidification of the pavement lasts for about 15 ​d. Data analysis indicates that the temperature variation inside the pavement was very stable, with maximum amplitude smaller than 2.25 °C in Sep. 2020. The longitudinal, transverse and vertical deformations of the pavement behaved in non-uniform distribution, and partial measuring points suffered from large tensile force. The concrete course had better deformation resistance than that of the soil base, and local interfacial micro void defects existed in the soil base. The preliminary results can help to understand the actual structural performance of cement concrete pavements based on the optical fiber sensing system.