DOWEL BAR RETROFIT. STH 13 CONSTRUCTION AND ONE-YEAR PERFORMANCE REPORT

From May to July 2001, Wisconsin Department of Transportation (WisDOT) rehabilitated State Trunk Highway (SHT) 13 in Wood County using retrofitted dowel bars. The objective of the dowel bar retrofit was to provide load transfer in the jointed plain concrete pavement and to prevent further faulting from occurring. Fifteen test sections and three control sections were established in this study to examine the performance of six different patch materials, the performance of two different dowel bar materials and the effects of sealed and unsealed joints on dowel bar retrofit. The potential benefits of this project include improving the ride quality, reducing future maintenance needs and extending the pavement service life. Patch material performance was assessed by test results including compressive strength at 7 and 28 days, air void content, permeability, and freeze/thaw durability. A one-year field review evaluating the in situ performance of the different patch materials was also conducted. While the Tamms Speed Crete 2028 performed the best in laboratory testing, the field review showed debonding and microcracks of both the Tamms Speed Crete 2028 and the Mn/DOT Specification 3U18 patch materials. To date, the other patch materials are performing well and show no distresses after one year in service. The long-term performance of the patch materials has not yet been determined. The test sections will continue to be monitored and inspected for deterioration, spalling or scaling of the patch material, deterioration of the pavement around the dowel bar slots, faulting of the slabs, corrosion of the dowel bars and overall pavement performance. Performance and test results may result in modifications to WisDOTS's material and construction specifications for dowel bar retrofit.