Effectiveness Analyses of Flexible Pavement Preventive Maintenance Treatments with LTPP SPS-3 Experiment Data

Abstract

The present study analyzes the effectiveness of preventive maintenance (PM) treatments of flexible pavements utilizing data obtained from the specific pavement study 3 (SPS-3) of the long-term pavement performance (LTPP) program online database. The PM treatments included in this study are thin hot mix asphalt (HMA) overlay, chip seal, slurry seal, and crack seal. International roughness index (IRI), rutting, fatigue cracking, longitudinal cracking, and transverse cracking were selected as indicators of pavement performance. Initial roughness change, long-term roughness change, and weighted distresses are used as measures of effectiveness. The logistic regression model is employed to investigate the influence of pretreatment roughness condition, pretreatment surface condition, and several other factors on the performance of PM treatments. Results from this study indicate that only thin overlay and chip seal are effective in retarding fatigue cracking. Thin overlay was also the only treatment effective in slowing long-term roughness increasing, rutting, longitudinal cracking, and transverse cracking. Sections with poor surface conditions deteriorate faster in terms of long-term roughness and longitudinal cracking. It is also found that soil type of subgrade, traffic volume, and structural capacities of sections exhibited significant influence on the effectiveness of PM treatments.