Real-time quantifying internal viscoelastic fatigue damage and evolution in self-sensing asphalt concrete via conductive-damage modelling

The self-sensing capabilities of conductive asphalt concrete provide the potential for real-time monitoring of internal damage within the material. This study aims to couple a conductive-damage model with J-integral based Paris’ law to quantitatively evaluate and predict the real-time evolution of viscoelastic fatigue damage in asphalt concrete. Laboratory indirect tensile (IDT) fatigue tests are conducted on the conductive asphalt concrete and fractional change in resistance (FCR) is monitored in real-time. The FCR is employed to predict the internal damage using the conductive-damage model. The predicted damage density is validated by the predictions from a continuum damage mechanics (CDM)-based viscoelastic fatigue damage model, which has been validated using the experimental data. Results demonstrate that the FCR correlates closely with horizontal resilient deformation, confirming its potential to characterize multi-stage fatigue processes of the asphalt concrete. The damage density predicted from the conductive-damage model aligns consistently with the CDM-derived damage, with an R2 reaches 0.9641, verifying the feasibility of characterizing the asphalt concrete’s fatigue damage using electrical signals. Furthermore, the fatigue damage growth derived from the conductive-damage model accurately reflects the damage evolution in the Phase II and III of the fatigue processes and can be modelled by the J-integral based Paris’ law.