BACKGROUND: Dowels are used in jointed portland cement concrete pavements to provide load transfer, reduce faulting, and improve performance. These dowels are placed either manually before concrete placement or during construction by automatic dowel bar inserters to expedite construction and reduce cost. Inspection of pavements in several states revealed that misalignment of dowels generally occurs regardless of the placement method. These inspections also revealed that slab cracking and other forms of distress may not always occur as a result of such misalignment. However, limited research has been performed to determine the extent of dowel misalignment in pavement construction and its effect on performance.

Research is needed to address the issues associated with dowel alignment and to develop approaches for estimating the short- and long-term effects of different levels and types of misalignment on performance. This research will help account for the effects of misalignment on performance thus improving analysis and design of concrete pavements. It will also develop guidelines on dowel alignment appropriate for use in performance related specifications.

OBJECTIVE: The objective of this research is to develop guidelines for dowel alignment in concrete pavements. The research shall address all forms and combinations of dowel misalignment (i.e., vertical and lateral skew and displacement).

Status: The project is complete.  The final report has been received; copies have been distributed to Program sponsors (state departments of Transportation).  NCHRP Report 637: Guidelines for Dowel Alignment in Concrete Pavements, documents the work performed under this project; copies are being distributed to Program sponsors (i.e., state departments of transportation). Appendixes A through D of NCHRP Report 637, which cover the literature review, field and laboratory test results, and finite element analysis, are available on line at https://trb.org/news/blurb_detail.asp?id=10299.