Optimal Thickness of Asphalt Overlay on Existing Concrete Pavement

Reflection cracking is a big problem for asphalt overlays on existing concrete pavements.It is not economic to completely prevent reflective cracking from occurring only by increasing the thickness of asphalt overlay,and in fact that method is not practical.Therefore,it is necessary to study the thickness of asphalt overlay.The paper analyzed the effect of thickness of asphalt overlay on reflective cracking utilizing the three-dimensional finite element.Based on the result of the mechanistic analysis,the boundary thickness between the single reflective cracking and couple reflective cracking was given,and the concepts ofoptimal width of delaminationand optimal thickness of asphalt overlaywere put forward.Furthermore,the width of couple reflective cracking was equal to the thickness of asphalt overlays.In consideration of the results of both mechanistic analysis and field tests,the thickness of asphalt overlay was suggested.