Bituminous Overlay Strategies for Preventive Maintenance on Pennsylvania Interstate Roadways

In 2008 the Pennsylvania Department of Transportation (PennDOT) initiated a two-stage process to identify appropriate bituminous overlay strategies for interstate pavements. The first stage consisted of a comprehensive review of the preventive maintenance practices and best practices at a national level and the second stage involved the identification of practices within each district in Pennsylvania. Identification of the most effective practices, both locally and nationally, can be used as a lead-in to the implementation of a strategy for the use of preventive maintenance procedures on interstate and interstate look-alike pavements in Pennsylvania. The process involved an extensive literature review process, outlining the key elements and practices dictating the use of preventive maintenance practices on interstate pavements. The most common techniques observed are thin hot mix asphalt overlays, micro surfacing, chip sealing, and polymer modified hot mix asphalt overlay. Various pavement evaluation factors were also identified, including climate, traffic conditions, relevant geography, life cycle costs, and pavement age. Literature review results were supplemented by a survey of practices of selected states and PennDOT districts. These results indicated the best practices with respect to the different performance evaluation criteria such as traffic conditions, pavement evaluation indices, application temperatures, pavement distress, thickness, and service life. The conclusions of the surveys and the literature review were analyzed to generate a list of maintenance techniques which are applicable for conditions in Pennsylvania. In an extension to this study, the identified best practices can be implemented on experimental test sites to validate the findings of this project.