Evaluation of Dowel Alignment Constructability in Portland Cement Concrete Pavements

Although dowel bars are an essential design feature of jointed concrete pavements to prevent pumping and faulting, few studies dealing with the constructability of dowel alignment have been conducted. With the emergence of the Magnetic Imaging Tools (MIT) Scan-2 as a nondestructive, robust method of locating dowels, it is now possible to efficiently evaluate the construction quality of dowel bar placement without damaging the newly constructed pavement. A brief review is presented of the results of recent field studies aimed at examining the constructability of doweled joints in concrete pavements. The dowel bar alignment data collected in this study encompass a wide range of design and environmental conditions and show that alignment within reasonable levels—considering equipment, mix design, as well as workmanship and consistency—is achievable in the field. Distress and performance analyses show that within these levels of misalignment, the pavement performance is not significantly affected. However, misalignment at a greater level may not be detrimental to pavement performance, and therefore performance-based guidelines may be less strict than the constructability levels collected in this study. Nevertheless, the results shed light on the level of alignment that can be reasonably achieved in the field.