Taylor Concrete

Part 1: General

1. Work includes furnishing and installing geogrid reinforcement, wall fill, and backfill to the lines and grades designed on the construction drawings.
2. Work includes furnishing and installing all related materials required for construction of the geogrid reinforced soil retaining wall as shown on the construction drawings.

1. Section 02276: ROCKWOOD Concrete Modular Retaining Wall

1. See specific geogrid manufacture's reference standards

1. Contractor shall check the geogrid upon delivery to assure the proper material has been received.
2. Geogrids shall be stored above -20°F.
3. Contractor shall prevent excessive mud, wet cement, epoxy and similar materials (which may affix themselves to the gridwork) from coming in contact with the geogrid material.
4. Rolled geogrid material may be laid flat or stood on end for storage.

1. Samples of all products used in this section.
2. Latest edition of manufacturer's specifications for proposed materials, method of installation and list of material proposed for use.

1. Soil testing and inspection services for quality control testing during earthwork operation will be supplied by the owner.

Part 2: Products

1. Geogrid products shall be high density polyethylene expanded sheet or polyester woven fiber materials, specially fabricated for use as soil reinforcement.
2. Concrete retaining wall units are as detailed on the drawings and are specified under Section 02276: ROCKWOOD Concrete Modular Retaining Wall.
3. Wall fill is a free draining granular material used within the concrete units.
4. Backfill is the soil which is used as fill for the reinforced soil mass.

1. Geogrid shall be the type as shown on the drawings having the property requirements described within the manufacturer's specifications.

1. A manufacturer's product shall be approved by the engineer prior to bid opening.

Part 3: Execution

1. Foundation soil shall be excavated to the lines and grades as shown on the construction drawings or as directed by the engineer.
2. Foundation soil shall be approved by the engineer to assure that the actual foundation soil strength meets or exceeds assumed design strength.
3. Over-excavated areas shall be filled with approved compacted backfill material.
4. Foundation soil shall be proof rolled prior to fill and geogrid placement.

1. Wall erection shall be as specified under Section 02276: ROCKWOOD Concrete Modular Retaining Wall.

1. The geogrid soil reinforcement shall be laid horizontally on compacted backfill and connected to the concrete wall units by placing geogrid between the concrete units. Place the next course of units, pull the geogrid taut and anchor before backfill is placed on the geogrid.
2. Slack in the geogrid should be removed.
3. Geogrid shall be laid at the proper elevation and orientation as shown on the construction drawings or as directed by the engineer.
4. Correct orientation (roll direction) of the geogrid shall be verified by the contractor.
5. Follow manufacturer's guidelines relative to overlap requirements of uniaxial and biaxial geogrids.
6. Pull geogrid taut to eliminate loose folds. Stake or secure back edge of geogrid prior to, and during backfill and compactions.

1. Backfill material shall be placed in 8" lifts and compacted to 95% of Standard Proctor.
2. Backfill shall be placed, spread and compacted in such a manner that minimizes the development of slack or loss of pretension of the geogrid.
3. Only hand-operated compaction equipment shall be allowed with 3' of the back surface of the ROCKWOOD units.
4. Backfill shall be placed from the wall rearward toward the embankment to ensure that the geogrid remains taut.
5. Tracked construction equipment shall not be operated directly on the geogrid. A minimum backfill thickness of 6" is required prior to operation of tracked vehicles over the geogrid. Turning of tracked vehicles should be kept to a minimum to prevent tracks from displacing the fill and damaging the geogrid.
6. Rubber-tired equipment may pass over the geogrid reinforcement at slow speeds, less than 10 mph. Avoid sudden braking and sharp turning.