Laboratory investigation of rutting performance for multilayer pavement with fiber Bragg gratings

- Specific FBG sensors were designed to monitor the deformation in asphalt mixtures.
- The deformation of asphalt specimens were monitored at different temperatures in different depths.
- A revised linear viscoelastic rutting prediction model was adopted and its reliability was proved.

Rutting is a significant problem for asphalt pavements, caused by factors such as channelized traffic and over loading, especially in urban areas and on highways. In recent decades, great emphasis has been put on this issue through various research methods. Fiber Bragg grating (FBG) sensing technology is widely used to detect the structure conditions due to its accuracy and simplicity and now gradually applied to pavements as a common detecting method. The objective of this study is to use FBG sensors to monitor the inner accumulated deformation of asphalt specimens in various depths at different temperatures, and seek for the relationship between accumulated deformation and temperature through an improved linear viscoelastic rutting prediction model. The results showed that the FBG sensors are reliable for monitoring accumulated deformation of asphalt pavements. For the full-depth rutting specimen, the deformation in the top and lower layer changed significantly with temperature. The middle layer had the largest unit accumulated deformation, which was not sensitive to temperature. It was also concluded that the revised model had enough accuracy to predict deformation of pavements, regardless of materials or structures.