This work consists of the full-depth removal of existing rigid pavement in areas exhibiting deterioration, correcting the subgrade, placing and compacting asphalt concrete, and restoring the shoulders.
The Engineer marks the limits of the areas to be repaired. The minimum longitudinal length of a repair is 6 feet (1.8 meters). All pavement repairs are the full lane width unless otherwise detailed by the plan.
The existing pavement is sawed full-depth at the limits established by the Engineer with a diamond saw blade. All diamond saw cuts shall be perpendicular to the surface of the pavement. Normally, the existing concrete pavement thickness is given in the plan. There may be older projects where the existing pavement was built thicker than specified in the new repair plan. Concrete sawing and removal depths may be as much as 1 inch (25 mm) greater than indicated on the repair plan without additional compensation to the Contractor.
If there is an existing asphalt overlay on the concrete pavement, the Contractor may elect to saw full-depth through the asphalt concrete and the Portland cement concrete. Depending on the thickness of each material, the Contractor may not be capable of sawing through both courses and may elect to make an offset saw cut through the asphalt course and remove enough asphalt to allow room for a diamond saw that would saw full-depth through the concrete pavement. If the Contractor elects to make offset cuts to facilitate the removal, the offset cut will not be measured for payment; only full-depth saw cuts that are made at the limits of the removal are measured for payment. Intermediate saw cuts made by the Contractor to facilitate removal by the lift out method are not measured for payment.
During hot weather, it may be necessary for the Contractor to saw only at night or morning when cooler temperatures prevail. Concrete pavement heats up and expands as temperatures rise during hot summer days. Diamond saw blades could be pinched and locked up during sawing by the expanding pavement slabs. Some contractors use a carbide-tipped saw to cut through the pavement within the repair area. This is permitted provided the Contractor does not damage the base under the pavement to be removed. All perimeter saw cuts must be made with diamond saws.
Removal of the concrete follows the full-depth sawing operation. The lift out method is required in order not to disturb the base under the pavement and to minimize the damage to the adjacent pavement that is to remain. Holes are drilled within the removal area and lift pins are inserted. The slab or portion of the slab is then removed by lifting the slab vertically with a crane or large backhoe. After lifting, loose debris left behind is removed by hand methods.
Removed pavement shall be disposed of in accordance with 202.02. The Inspector shall determine and document where and how pavement is being disposed by the Contractor.
The use of a pavement breaker and backhoe for removal is not permitted unless the Engineer determines that the lift out method is not practical because of extensively deteriorated pavement, existence of asphalt concrete full-depth repairs, or old concrete pavement repairs which are extensively cracked and deteriorated. There will be no additional compensation for removal of the existing pavement with a pavement breaker and backhoe.
Prior to placing the asphalt concrete in the removal area, any base or subgrade that is disturbed below the level of clean out is removed. The repair area must be compacted to the satisfaction of the Engineer. All vertical faces shall be cleaned and coated with asphalt material according to 401.14.
The pavement replacement is constructed by placing and compacting Item 301 or 448 Type 2 material in two or more lifts according to 401.16. Note that the plans for the project may specify the use of another material. The first lift, and all intermediate lifts, must be thoroughly and uniformly compacted using suitable mechanical compaction equipment operated over the entire replacement area.
The final lift must be compacted using a pneumatic tire roller that conforms to 401.13. At least 18 passes should be made over all points on the entire surface of the repair area. A pass is defined as one movement of the roller over the surface of the patch. As the rolling progresses, additional patching material may need to be added, as necessary, to produce a smooth surface flush with the existing pavement surface.
Each lift shall be continuously compacted while the material is in a workable condition throughout the depth of the lift.
If an overlay is not scheduled to be placed within 60 days of the repair, the perimeter of the repair shall be trimmed vertically 1.5 inches deep from the surface before placing the final lift of asphalt concrete.
If the Contract does not include resurfacing, the perimeter surface of the repaired areas must be sealed with a 4” (100 mm) wide band by applying approved 702.04 asphalt material, RS-1, RS-2, CRS-1, CRS-2, or 702.01 approved PG binder.
After completing repairs, the existing shoulders must be repaired to the condition that existed prior to the repair work.
1. Locate, mark, and record all areas to be repaired.
2. Measure and record saw cuts. Full-depth saw cuts are an additional pay item paid by the linear foot.
3. Document removal of deteriorated pavement. Note condition of existing adjacent pavement.
4. Document the disposal of removed pavement.
5. Document preparation of subgrade.
6. Document that the area was cleaned and tacked with 407 tack coat.
8. Document the location of repairs and saw cuts, measurements, and calculations, and pay per 252.06.
9. Show documentation on CA-D-6 or other approved form.