Thin and Ultra-Thin Whitetopping : A synthesis of Highway Practice

This report of the Transportation Research Board summarizes available information to document how departments of transportation and other agencies and owners are currently using thin and ultra-thin white topping (TWT and UTW) overlays among various pavement rehabilitation alternatives. This study covered all stages of the proper application of white topping overlays, including project selection, design, materials selection, construction, maintenance, and eventual rehabilitation or replacement. This synthesis provides the practitioner with a comprehensive source for the state of the practice, as well as state-of-the-art in TWT and UTW overlay applications. It is designed to serve as a quick reference guide and as a training aid. This synthesis report included a review of published literature related to all stages of the proper application of white topping overlays and a broad range of citations has been gathered, from practical case studies to reports of theoretical modeling. In addition, a survey of the highway community was undertaken that provided first-hand results of experiences with TWT and UTW. Responses were received from both the public and private sectors. A panel of experts in the subject area guided the work of organizing and evaluating the collected data and reviewed the final synthesis report. A consultant was engaged to collect and synthesize the information and to write the report. Both the consultant and the members of the oversight panel are acknowledged on the title page. This synthesis is an immediately useful document that records the practices that were acceptable within the limitations of the knowledge available at the time of its preparation. As progress in research and practice continues, new knowledge will be added to that now at hand