Impact of Site Factors on the Effectiveness of Flexible Pavement Preservation Treatments

Pavement preservation has become a common practice in the management of pavement network across the country. However, the effectiveness of the preservation treatments vary depending on numerous factors e.g., construction practices, traffic, climate and pre-existing surface conditions and structural capacity. The purpose of this paper is to determine the impact of the site factors on the effectiveness of flexible pavement preservation treatments in terms of service life extension (SLE). The data from the Long-Term Pavement Performance (LTPP) SPS-3 experiment were utilized to compare the pavement SLE among different preservation treatments (slurry seal, chip seal, crack seal, and thin overlay) based on structural and functional performance measures. The SLE is a measure of treatment effectiveness and can be obtained by comparing the performance between treated and untreated control pavement section. The flexible pavement performance measures considered were structural and thermal cracking, rutting, and surface roughness, bleeding, raveling, and friction. The impact of various site factors (e.g., traffic, climate and pre-existing surface conditions) was determined by performing statistical analyses including analysis of variance (ANOVA) and multiple linear regressions. The comparison of SLEs among different treatments showed the most effective preservation treatment under different site conditions. The results from statistical analyses elaborated the significance of site factors in defining the efficacy of various preservation treatments.