§ 5.6. Subgrade preparation for all streets.

5.6.1 Procedures and requirements for subgrade preparation.

1)

Subgrade preparation shall be in accordance with Georgia DOT specifications and these regulations.

2)

If any sections of the subgrade are composed of topsoil, organic or other unsuitable or unstable material (the top 12 inches less than 100 cubic pounds), such material shall be removed and replaced with suitable material and then thoroughly compacted as specified for fill or stabilized with stone or a geo-textile, geo-grid or other suitable materials approved by the department.

3)

Fill shall be placed in uniform, horizontal layers not more than eight inches thick (loose measurement). Moisture content shall be adjusted as necessary to compact material to 95 percent of maximum dry density except for the top 12 inches, which shall be compacted to 100 of maximum dry density.

4)

After the earthwork has been completed, all storm drainage, water, and sanitary sewer utilities have been installed within the right-of-way as appropriate, and the backfill in all such ditches thoroughly compacted, the subgrade shall be brought to the lines, grades and typical roadway shown on the plans.

5)

Utility trenches cut in the subgrade shall be backfilled as specified herein. Compaction tests at the rate of one per 150 feet of trench shall be provided to verify compaction.

6)

The subgrade must pass roll testing prior to placement of the base material. With the approval of the Paulding County Department of Transportation, a geo-textile or grid may be used to stabilize a subgrade that does not pass proofrolling.

7)

When the street is to be used for construction traffic before the paving work is completed, a layer of stone (except crusher run) shall be laid as a traffic surface. This material shall not be used as a part of the base material. It may be worked into the subgrade, or it shall be removed before the base course is set up for paving.

8)

Provisions shall be made to drain low points in the road construction when the final paving is delayed. A break in the berm section is required when the curbing has not been constructed. Once curbing has been installed, a three inch notch in the curb at the throat section of the low point inlet shall be cut to the depth of the binder course to provide drainage. No areas of ponding shall be created. After the final pavement surface coat has been applied, the notch shall then be filled in.