Tolerances for Placement of Tie Bars in Portland Cement Concrete Pavement

Longitudinal joints in Portland Cement Concrete (PCC) pavement slabs require tie (dowel) bars to control joint opening resulting from thermal stresses. Inspections of PCC pavements by the South Dakota Department of Transportation (SD DOT) using ground penetrating radar (GPR) revealed that it is common for tie bars to be either misplaced or completely missing at some locations. It is unclear if tie bar misplacement results in increased maintenance costs or reduced pavement service life. Tie bar misalignment tolerances that have been established in existing specifications are not based on PCC pavement research or economic data. This research study investigates the effects of different tie bar misalignments on the tie bar performance to establish acceptable placement tolerances. A comprehensive literature review was carried out to assess existing specifications and past studies. The effect of different misalignment configurations and magnitudes on the longitudinal joint performance was examined by conducting laboratory experiments on PCC slabs incorporating four different misalignment configurations and four different misalignment magnitudes. The results showed that vertical and longitudinal translation misalignments had no significant effect on the performance of the longitudinal joint, while vertical skew misalignment had a mild effect only on joint faulting. Horizontal skew misalignment, however, caused a significant increase in both joint opening and joint faulting. Horizontal skew misalignment also caused a significant decrease in the tie bar load that initiates bar yielding. A simplified method was developed to conservatively estimate the allowable load in a tie bar for horizontal skew misalignments. Based on the results, recommendations are to reduce the horizontal skew tolerance limit from 18 in. to no more than 16 in.

• Record URL:
  https://www.ugpti.org/resources/reports/details.php?id=993
• Supplemental Notes:
  • This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
• Corporate Authors:

  South Dakota State University, Brookings

  Department of Civil and Environmental Engineering
  Brookings, SD  United States  57007

  South Dakota Department of Transportation

  700 East Broadway Avenue
  Pierre, SD  United States  57501

  Mountain-Plains Consortium

  North Dakota State University
  Fargo, ND  United States  58108

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Authors:
  • Ghadban, Ahmad A
  • Wehbe, Nadim I
  • Olson, Walker
• Publication Date: 2020-8

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 74p

Subject/Index Terms

• TRT Terms: Alignment; Concrete pavements; Engineering tolerance; Joints; Laboratory tests; Literature reviews; Pavement performance; Portland cement concrete; Tie bars
• Subject Areas: Design; Highways; Pavements;

Filing Info

• Accession Number: 01751953
• Record Type: Publication
• Report/Paper Numbers: MPC-20-417
• Contract Numbers: MPC-440
• Files: UTC, TRIS, ATRI, USDOT, STATEDOT
• Created Date: Sep 17 2020 5:51PM