Use of Long-Term Pavement Performance Data for Calibration of Pavement Design Models

Abstract

The benefits of long-term pavement performance data for calibration of the AASHTO flexible pavement design model for Ontario conditions are documented. To ensure that the AASHTO-Ontario pavement design model reflects Ontario pavement design practice and matches the observed pavement performance, long-term pavement performance data for 65 flexible pavement sections were used. Thirty-nine sections had original construction, and 26 sections received one rehabilitation treatment (overlay). The data for each section included the type and thickness of paving materials, subgrade type, pavement performance, and traffic loads. The results of the calibration and verification process indicate that for new flexible pavement design the AASHTO-Ontario model yields results that are in good agreement with the observed pavement performance. For overlays, there was a large difference between the predicted and observed performance. This indicates that considerably more observations (pavement sections) are required for assessment of rehabilitation designs than for the original construction because the overlays are not always built for structural reasons only. Possible avenues for using long-term pavement performance data to establish the values of input parameters such as structural layer coefficients and modulus of subgrade are also described. Even relatively limited long-term pavement performance data provide valuable information for the calibration and verification of pavement design methods.