Effectiveness Evaluation of Preventive Maintenance Treatments on Asphalt Pavement Performance Using LTPP Data

Preventive maintenance (PM) has been a pavement asset management strategy widely used by many highway agencies to improve pavement conditions, restore pavement serviceability, retard deterioration, and prolong pavement life. Practical experience shows that the effectiveness of different kinds of PM treatments varies for different distresses in short-term pavement performance which is related to the long-term pavement performance. The objective of this study is to evaluate the effectiveness of PM treatments in short-term asphalt pavement performance using the Specific Pavement Studies (SPS-3) data of the Long-Term Pavement Performance (LTPP) Program. The PM treatments included in the study were chip seal, crack seal, slurry seal, and thin overlay, and the related SPS-3 data were retrieved from LTPP for the study. Longitudinal cracking, transverse cracking, alligator cracking, roughness, and rutting were employed as indicators to evaluate possible pavement performance improvements. Statistical methods were applied to compare the effectiveness of PM treatments in terms of the performance indicators of longitudinal cracking, transverse cracking, alligator cracking, roughness, and rutting. In addition, mixed-effects logistic regression was conducted to find the significant influential factors and quantify the influence of various factors such as temperature, precipitation, cloud cover, subgrade material, truck traffic, and asphalt concrete layer thickness on the improvements of pavement performance. The analysis results showed that chip seal and thin overlay have most significant effects on short-term cracking improvements. Thin overlay has the best effect on short-term roughness and rutting improvements. As of influential factors, temperature, cloud cover, and subgrade material are significantly important factors in PM treatments. These results may provide performance data enabled understanding of the effectiveness of PM treatments.