Determine Old Asphalt Pavement Milling ThicknessBased on Pavement SurfaceDeflection Control

摘要

In order to determine optimum pavement milling thickness when old asphaltrnpavement structure strength deteriorates to some degree，the back calculation methodrnis usually considered. Based on the multi-layer elastic system theory, the change lawrnof the deflection before and after old pavement milling is calculated using the theoryrnof orthogonal design. The change law of the deflection before old pavement millingrnand old road equivalent rebound modulus after milling is also calculated using thernuniform design method. Meanwhile, this paper developed correlations between therndeflections before and after old pavement milling for different milling thickness, andrnthe relationship between the deflection before old pavement milling and the old roadrnmodulus after milling using regression analysis. The results indicate that thernexponential equation usually gives better correlation. When the deflection valuernbefore old pavement milling and milling thickness value are small, the differencernbetween the deflection before and after old pavement milling is relatively small.rnFinally, according to the calculation results, the design criterion of asphalt pavementrnmilling based on the old pavement surface deflection control is proposed. Thernexample indicates that this criterion is simple and reasonable, and has a good practicalrnvalue, which can provide the basis for the determination of asphalt pavement millingrnthickness and the design of asphalt overlay.