Need for Improved Specifications on Dowel Bar Placement Tolerance

While the importance of achieving good dowel alignment is widely recognized, determining the alignment of dowel bars encased in hardened concrete had been a difficult and costly process prior to the availability of MIT Scan-2. MIT Scan-2 is a state-of-the-art, nondestructive testing (NDT) device, which allows for efficient and accurate measurement of dowel alignment. Because of the past difficulties in measuring dowel alignment, the magnitude of misalignment at which the poor dowel alignment becomes a pavement performance issue is not well known. Nevertheless, nearly every state has tight specifications on dowel placement tolerance. With the availability of a new, practical method of measuring dowel alignment, there is a critical need to review the effects of dowel misalignment on pavement performance and develop rational guidelines on dowel placement tolerance. A comprehensive national study is underway (National Cooperative Highway Research Program NCHRP Project 10-69, Guidelines for Dowel Alignment in Concrete Pavements) that is aimed at evaluating the effects of dowel alignment on pavement performance and developing guidelines for dowel placement tolerance. In the interim, the findings from several recent studies could be put into practice. Based on the lessons learned from recent dowel-alignment-related studies and field observations, this paper provides recommendations on dowel placement tolerances. An important change proposed is the consideration of dowel alignment on joint-by-joint basis and the inclusion of the provision to allow a limited number of isolated locked joints.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; Photos; References; Tables;
  • Pagination: 14p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01043597
  • Record Type: Publication
  • Report/Paper Numbers: 07-3431
  • Files: PRP, TRIS, TRB
  • Created Date: Feb 8 2007 8:07PM