New Approach in Determining Pay Adjustment Factors Based on Rutting Performance Modeling for Asphalt Pavements

In this study, an approach in determining the asphalt pay adjustment factor was proposed by evaluating the rutting performance based on different asphalt concrete acceptable quality characteristic (AQC) parameters. These AQC parameters are asphalt binder content, percent passing a 0.075-mm sieve ($P_{200}$), percent cumulative retained on a 4.75-mm sieve ($P_4$), field air voids (AV), and thickness. New specification limits for Seoul City, Korea, were initially established using a percent within limits (PWL) analysis, and these limits were then compared with the current limits in Korea and the US. A rutting model from a previous study was then used to evaluate the relative performance (RP) of the pavement, which was utilized in determining corresponding pay factors. Two different approaches were conducted wherein the first approach included the combined PWL and RP analysis and the second used the average RP analysis only. It was found that each approach has its own advantages and disadvantages when evaluating the pavement’s pay factor; therefore, the most appropriate approach in determining the pay adjustment factor was established.