Evaluation of the Effect of Interlayer Bonding Condition on the Deterioration of Asphalt Pavement

In this study, to investigate the effect of interlayer bonding condition on the deterioration of asphalt pavement, we conducted numerical analysis based on multi-layer elastic theory, verification of numerical analysis results by experiments on a full-scale test track, and comparison of the progress of deterioration based on accelerated loading tests conducted on the test pavement. Firstly, the analysis indicated that stronger tensile strain could occur on the upper side of the interlayer when the interlayer bonding weakens. Furthermore, the test pavement simulating interlayer debonding showed the same strain tendency as the analysis. These results suggest that if the interlayer debonding continues, the pavement may suffer early fatigue failure. On the other hand, there are some results that are not consistent with those of the analysis, such as the magnitude of deflection in the test pavement; thus, further investigation is required. Furthermore, because of the accelerated loading on the test pavement, the sections where the layers were debonded immediately after construction became bonded. Since the deflection of the test pavement did not change significantly from that immediately after construction, and no conspicuous damage such as cracks was observed on the road surface, it is considered necessary to continue follow-up surveys.