Statistical Analyses of Field Serviceability of Throw-and-Roll Pothole Patches

In order to evaluate the effectiveness of different pothole patching methods and materials, it is necessary to conduct a long-term field survey of patches installed at different environmental and traffic conditions. The research reported in this paper investigated the service life of different throw-and-roll pothole patches through a 14-month field survey. Three statistical methods, including (1) logistic regression, (2) classification tree, and (3) survival analysis, were employed to characterize the influence of different factors on the service life of installed patches, and to identify the performance of different patching materials. The factors investigated in the research reported in this paper included the length, width, and depth of patches; traffic level; speed limit; and freeze times. All the three statistical methods identified similar trends of the significance of factors and performance rankings of materials. Generally, patches installed on road sections with less freeze cycles, lower speed limit, and lower traffic level had significantly longer service life. A cold bag mix had significantly longer service life. In addition, the classification tree method indicated that significant influences of weather conditions and materials on the service life of patches were only observed around 1 year after the installation, indicating the necessity of the long-term survey. (C) 2015 American Society of Civil Engineers.