Assessment of fatigue damage in asphalt mixture using an acoustic emission approach

Fatigue failure is the main damage forms of asphalt mixture. Acoustic emission (AE) is an effective technique for continuously monitoring the development of fatigue damage in asphalt mixture. Firstly, the AE characteristic and mechanical behaviour of asphalt mixture and their relationship were investigated by performing four-point bending fatigue test and AE test. Furthermore, the parameters of continuum damage mechanics model that describes the deterioration process of asphalt mixture were calibrated in according with the AE technique. Finally, simulation analysis on the four-point bending fatigue test of asphalt mixture is performed. The results indicated that the AE parameters could reflect the changes of mechanical characteristic. The variation of AE energy and dissipated energy had a similar tendency. There is a strong correlation between the result of continuum damage mechanics model and mechanical test. The numerical results show that the definition of damage variable based on AE energy is reliable and reasonable. This research would provide a new idea for the application of AE technique on diagnosing the fatigue damage evolution process of asphalt mixture.