jackhammers tend to damage the concrete around the cuts). The epoxy-coated dowel bars are placed in the slots, then the slots are filled with grout and the joints or cracks are filled with waterproof caulk. The final step is to diamond-grind the joint to remove both excess grout and any displacement of the panels. The final step often involves diamond-grinding of the entire road surface to remove any bumps or dips. Without the dowel bar retrofit this grinding would have to be repeated every six to eight years, but it is predicted that the retrofit will greatly increase this interval. Dowel Bar Retrofit has been proven to outlast Asphalt Overlay by at least ten years, and significantly improves ride quality. Dowel bar retrofit process For dowel bar retrofit, dowels, bond breaker, expansion caps, dowel bar support chairs, foam core insert, caulking filler, non-shrink concrete backfill material and submittals are needed. The dowels need to be smooth, round, epoxy and made of bond breaker coated steel conforming to requirements. The bond breaker is to be applied on all surfaces of the dowel bar. The expansion caps belong at each end of the dowel bar and the dowel bar support chairs are used to firmly hold the dowels centered in the slots during backfill operations. The foam core insert is used to re-establish the joint or crack, which allows the bar within each side of the slot to expand and contract. The caulking filler is used to prevent backfill material from flowing into the joint or crack. Non-shrink concrete backfill material that is tested as rapid set concrete patching materials is recommended for use on DBR projects. First, make two saw cuts in the pavement to outline the longitudinal sides of each dowel bar slot. Saw to a depth and length that allows the center of the dowel to be placed at mid-depth in the pavement slab. Saw slots parallel to each other and to the center line of the roadway with a maximum tolerance of 1⁄4-inch per 12 inches of dowel bar length. Employ saws equipped with gang-mounted diamond blades capable of cutting three or four slots simultaneously in each wheel path. Skewed joints or cracks may require slots longer than the length specified in the plans. Remove water and paste residue from the pavement surface immediately by means of a vacuum attachment on the sawing machine. For smaller projects, a