PERFORMANCE MODELS FOR FLEXIBLE PAVEMENT MAINTENANCE TREATMENTS

Using actual pavement performance data, nine flexible pavement maintenance performance models were developed. The models relate the pavement's present serviceability index (PSI) to its age, materials properties, traffic loadings, and environmental conditions. To develop the performance models, data collected by the Nevada Department of Transportation (NDOT) personnel over the life of 123 projects were used. Statistically significant samples were drawn from these projects for each of the three maintenance techniques that NDOT commonly employs. The maintenance techniques include flush seals, sand seals, and chip seals. To produce statistically accurate predictions, performance models for each technique were developed separately for each of NDOT's three districts. In cases where a large number of projects were available, some projects were set aside for a model verification study. Using the data from the set-aside projects, the nine models were tested by comparing the predicted performance to the performance observed at the projects. These comparisons showed excellent correlations between the PSI values predicted by the models and those observed.