Evaluation of Dowel Bar Alignment and Effect on Long-term Performance of Jointed Pavement

Dowel bars are the current preferred method for providing load transfer for jointed plain concrete pavements (JPCP). For proper load transfer to occur, the dowels must be placed properly, i.e., in the middle of the slab, horizontal to the grade, and in the direction of traffic flow. This project evaluated JPCP performance with relation to dowel bar alignment utilizing the new MIT-SCAN2-BT technology. Four to eight jointed concrete pavements of each of the following ages were measured: 0-10 years, 10-20, years, and 20+ years of age to determine the effects of dowel bar misalignment on pavement performance indicators such as faulting, load transfer, and ride quality. For each project, about 5 percent of the joints were tested, (about 15 joints per mile). The joints were tested in groups of five at 0.3-, 0.3-, and 0.4-mile increments. Every joint on the newly constructed I-49 corridor from LA1 to the Arkansas state line was measured. The results of this project show that the MIT-SCAN2-BT device is accurate, but the flexible track is fragile and will need repairs in extended testing scenarios. Testing rates range from 32-45 joints per hour for full width pavement sections in a closed road condition. The pavement surface must be free of debris and measurements should be conducted prior to application of raised pavement markers. Pavements constructed over the past 30 years that contain dowel bars in the joint detail are performing well with regards to measurable faulting. Measured joints were constructed with no horizontal skew, vertical translation, vertical tilt, or horizontal translation. The results indicated that the pavement sections should not exhibit joint lock due to skew or tilt. The MIT-SCAN2-BT device is very capable of locating and measuring dowel bars and assemblies. It is also capable of determining whether or not a bar is missing, or if the load transfer device is something other than a dowel bar. The results also indicate that the effect of longitudinally translated dowel bars is negligible. Acceptable long-term performance was observed in joints with less than 4 in. of embedment and some joints with 2.5 to 3 in. of embedment. The Louisiana Department of Transportation and Development’s current dowel placement specifications lead to acceptable long-term joint performance.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Maps; Photos; References;
  • Pagination: 47p

Subject/Index Terms

Filing Info

  • Accession Number: 01671745
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/LA.17/595
  • Files: NTL, TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Jun 4 2018 4:56PM