In Buena Vista County, Iowa, a study sponsored by the Iowa Highway Research Board and Iowa Department of Transportation evaluated different dowel bar materials for local road pavements. The project, conducted by Iowa State University, included diamond grinding to improve the international roughness index and reduce faulting. The findings indicated that fiber-reinforced polymer (FRP) dowels performed better in terms of pavement smoothness compared to steel dowels.

The Minnesota Department of Transportation (Mn/DOT) constructed experimental test sections of retrofit load transfer and DBR on U. S. Highway 52, a divided 4-lane highway near Zumbrota, Minnesota that was originally constructed in 1983. Multiple dowel bar configurations were evaluated.

The Buena Vista County staff developed a construction project to retrofit the dowels in the joints and grind the surface of the test pavement. The contract included items for the preparation and the installation of dowels in each of the transverse joints in the pavement. After a careful analysis of the dowel bar retrofit (DBR) sections, the conclusion was made that FRP bars maintain a better IRI. However, this comes at a higher cost.

This checklist for partial depth repair of portland cement concrete is one in a series created to guide state and local highway preservation/maintenance and inspection staff on the use of innovative pavement preservation techniques. FHWA uses its partnerships with different pavement preservation organizations including American Association of State Highway and Transportation Officials, and state and local transportation agencies to promote pavement preservation.

Concrete pavement restoration (CPR) techniques have gained greater national significance as DOT agencies attempt to further extend infrastructure service lives prior to required major rehabilitation or reconstruction. This report consolidates best practice case studies for six CPR techniques: cross stitching, dowel bar retrofit, diamond grinding, full depth repair, partial depth repair and slab stabilization.

Partial depth repair (PDR) is a well-established technique applied to an existing concrete pavement that has spalls along joints and cracks. Nevertheless, there have been a number of failures of PDRs over the years on projects across the country. This Tech Brief focuses on PDR in Minnesota but also includes information from Missouri, Utah, Washington, Georgia, and California.