Design Considerations for Flexible Pavement Widening (0-5429-1)

The Texas Department of Transportation, TxDOT, prepared Safety Bond Projects that were to undertake the letting of construction projects for flexible pavement widening on current pavement widths less than 24'. Typically, these projects were approximately 20 foot widths, where widening will extend the pavement width to approximately 27 to 28 feet. Few guidelines exist statewide for assisting designers in selecting the appropriate widening technique. Current specifications provide a basic framework for construction performance and compaction; however, there are major pavement related issues that are not addressed. Some of these issues include: meeting density requirements on narrow sections, placing the joint in the wheel path, and not matching pavement sections, which can cause moisture to be trapped in the original structure. To address these considerations and others, this project focused on an extensive literature review and a survey of various district personnel regarding project selection and issues faced during construction of widening projects. This study concluded with a site-specific approach to selection of proper material use and/or re-use, construction technique and traffic control to warrant rapid construction and long-term stability of the widened pavement, which is summarized into a flexible pavement widening guideline.