Paragon 1-1/4in Dowel Bar Chair (Carton of 600)

1-1/4" Dowel Bar Chair (500/Ct)

Dowel Bar Chairs and Caps are essential components specifically engineered for dowel bar retrofit applications in concrete pavements. These chairs provide stable and accurate support for dowel bars, ensuring they are positioned correctly within the concrete slots before grouting. This precise placement is crucial for the effective transfer of loads across joints and cracks, thereby extending the service life of the pavement.

The Dowel Bar Retrofit Process

Many departments of transportation are now retrofitting older concrete highways with epoxy-coated dowel bars to restore load transfer capabilities and improve road quality. This process is a cost-effective alternative to full-depth reconstruction. The typical retrofit procedure is as follows:

1. Slot Cutting: The process begins by making parallel cuts across existing transverse joints or cracks using ganged diamond saws. Typically, three slots are cut in each wheel path to ensure adequate load distribution.
2. Concrete Removal: The concrete between the saw cuts is carefully removed using lightweight pneumatic hammers (jackhammers). Using lightweight tools is critical to prevent spalling and damage to the surrounding concrete, which would compromise the integrity of the repair.
3. Dowel Bar Placement: After clearing debris from the slots, Dowel Bar Chairs are placed inside. Epoxy-coated dowel bars are then set into the chairs, ensuring they are held at the correct height and alignment. A foam core board is placed at the center of the slot to re-establish the joint and allow for slab movement.
4. Grouting: The slots are filled with a high-strength, fast-setting grout or patching material, which encases the dowel bars and bonds with the existing concrete.
5. Joint Sealing and Finishing: The joints or cracks are then filled with a waterproof sealant or caulk to prevent moisture ingress. The final step is to diamond-grind the joint to remove any excess grout and ensure a smooth, level surface across the repaired area.

Benefits of Dowel Bar Retrofitting

Often, the entire road surface is diamond-ground after retrofitting to eliminate bumps and dips, resulting in a superior ride quality. Without this dowel bar retrofit, grinding would need to be repeated every six to eight years. The retrofit process significantly extends this interval.

Proven to be a durable and long-lasting solution, dowel bar retrofitting outlasts a standard asphalt overlay by at least ten years while significantly improving ride quality and extending the functional life of the pavement.