858-1 DESCRIPTION
This work will be considered an adjustment where the item is raised or lowered two feet or less in elevation. Raising or lowering beyond the two feet will be measured and paid for separately. For example, if a 3-foot elevation differential is involved, the top two feet of construction is considered and paid for as an adjustment and the remaining one foot is considered and paid for at the contract unit price per linear foot for “Masonry Drainage Structures.”
858-3 CONSTRUCTION METHODS
All existing walls shall be removed to a depth sufficient to provide for the adjustment. The adjustment will be performed with the appropriate item of either brick masonry or Portland Cement Concrete. If the Engineer permits the utilization of cast iron or steel fittings for an adjustment, these fittings must be securely attached to existing wall. This may require welding by the Contractor. The Engineer should not approve them for use unless the attachment will eliminate movement. They shall be installed in a manner so as to eliminate movement of the fitting.
The concrete used to backfill adjustments in an existing pavement shall be cured and protected from traffic until such time as the concrete has obtained enough set that traffic will not damage it. The Engineer may approve the use of “Sakrete Concrete” mix for backfill of the adjustment provided the manufacturer's instructions on the bag are followed for its use. No traffic or paving shall be allowed around the adjusted structure until 2500 psi strength is achieved or 72 hours, whichever is first, after the concrete is cast. Bituminous materials will not be permitted as backfill. Backfill of areas outside of existing pavement should be accomplished by the use of materials comparable to the existing adjacent area. In areas to be surfaced or resurfaced, this adjustment shall be made before the final layer of surfacing material is placed.
The Technician should check these adjustments to ensure that the surface of the adjustment in paved areas will conform to the pavement grade and slope. It is necessary that string lines, straightedges, etc., be used to properly adjust and orient these items so they will meet the surface requirements of the paved surface. When the lid of a manhole is more than 1/8 inch depressed into an existing ring, the local utility owner should be contacted to secure a replacement manhole ring and cover. Even the best adjustment will ride poorly with a worn ring.
If traffic will be allowed to travel over the adjusted structure prior to placing the surfacing material flush with the top, ramps must be constructed of asphalt at least three feet wide on all sides of the structure before removing the barricades. This temporary asphalt ramp shall be placed within 24 hours of the adjustment and should be removed prior to the final surfacing. The contract special provisions may be more restrictive and should be consulted. The final surface should be placed within seven days of the adjustment.
858-4 MEASUREMENT AND PAYMENT
If the contractor elects to lower the utility prior to milling and raise in conjunction with the final surface, pay for only one adjustment.
ADDITIONAL RESOURCES
