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72-16.03 CONSTRUCTION

72-16.03A General


Areas where gabions are to be placed must be constructed to the lines and grades shown.

If fabric is shown, place the fabric on the subgrade, backslope, and sides of the excavations. If earth fill is to be placed over the gabions, place the fabric on top of the gabions before placing the earth fill.

Gabions must be divided by diaphragm panels such that baskets are 36-inch long cells.

72-16.03B Assembly


Individually assemble empty gabion baskets and successively join the baskets. Assemble the individual mesh panels, base, front, ends, back, diaphragms, and lid, and successive gabions such that the strength and flexibility along the joints is comparable to a single panel.

Assemble the gabions as empty units. Rotate panels and diaphragms into position and join them along the vertical edges.

For twisted wire mesh, construct joints using alternating double and single half hitches and locked loops made at 4-inch nominal spacing. Use 13.5-gauge standard tie wire. Do not construct joints with simple spiraling or looping without locking, of the tie wire.

For welded wire mesh, construct joints using either of the following:

1. Standard tie wire and alternating double and single half hitches and locked loops, in every mesh opening along the joint

2. 9-gauge spiral binders with the spiral binder passing through every mesh opening along the joint. Crimp both ends of the spiral binder and secure it in place.


You may use temporary fasteners to hold panels at gabion-to-gabion joints. The temporary fasteners may remain in place.

Use either interlocking fasteners or overlapping fasteners. Place a fastener at each mesh opening along the joint. For PVC coated wire, the spacing of fasteners must be at least 10 fasteners per 36 inches. For wire without PVC coating, the spacing of fasteners must be at least 10 fasteners per 40 inches.

Set individual gabion baskets in place. Successively join the basket to the adjacent basket with 13.5-gauge tie wire or 9-gauge standard spiral binder before filling the basket with rock. In 1 pass, the tie wire or spiral binder must secure all selvage or end wires of the panels along the joint.

If forming successive gabion-to-gabion joints with alternative fasteners, use 1 alternative fastener at each mesh opening. The alternative fastener must contain and secure all wires along the joint.

Join gabion baskets along the front, back, and ends, including the top and bottom of adjacent gabions.

Step and stagger multi-layered gabion configurations. Join each layer of gabion to the underlying layer along the front, back, and ends.

Join shear key and counterfort gabions to the underlying gabions along the front, back, and ends.

For transitional gabions, fold, cut, and fasten the gabion baskets as shown or as authorized.


72-16.03C Filling


Before filling each gabion basket, straighten any kinks and folds in the wire and align the baskets.

Place rock in the basket and preserve the alignment. Avoid bulges and minimize voids. Exposed rock surfaces must have a smooth and neat appearance. Sharp rocks must not project through the wire mesh.

Use internal connecting wires or preformed stiffeners to produce a flat, smooth external surface.

When filling 36-inch-high gabions, place the rock in 12-inch-deep layers. When filling 18-inch-high gabions, place the rock in 9-inch-deep layers. Install internal connecting wires or preformed stiffeners before adding additional layers.

The last layer of rock must slightly overfill the gabion basket such that the lid will rest on rock when the lid is closed.

Lids must be tied along the front, end, and diaphragms with 13.5-gauge tie wire or 9-gauge standard spiral binder. In 1 pass, the tie wire or spiral binder must secure all selvage or end wires of the panels along the lid.

If securing the lid with alternative fasteners, use 1 alternative fastener at each mesh opening. The alternative fastener must contain and secure all wires along the lid.

72-16.04 PAYMENT


The payment quantity for gabion is the volume determined from the dimensions shown or the actual volume of gabions placed.

72-17 EXISTING SLOPE PROTECTION

72-17.01 GENERAL

72-17.01A General


Section 72-17 includes specifications for performing work on existing slope protection.

Work performed on existing slope protection must comply with section 15.


72-17.01B Material


Not Used

72-17.01C Construction


Not Used

72-17.01D Payment


Not Used

72-17.02 REMOVE SLOPE PAVING

72-17.02A General


Section 72-17.02 includes specifications for removing slope protection.

72-17.02B Materials


Not Used

72-17.02C Construction


Not Used

72-17.02D Payment


The payment quantity for remove slope paving is the area of the slope paving measured before starting removal

72-18–72-25 RESERVED
73 CONCRETE CURBS AND SIDEWALKS

73-1 GENERAL


73-1.01 GENERAL


Section 73-1 includes general specifications for constructing concrete curbs, sidewalks, and their appurtenances, such as gutter depressions and island paving; and curb ramps and driveways.

Steel dowels, reinforcing steel, and welded wire reinforcement must comply with section 52.


73-1.02 MATERIALS

73-1.02A General


Concrete for curbs, sidewalks and their appurtenances must be minor concrete containing at least 463 pounds of cementitious material per cubic yard.

For extruded or slip form curb construction, the maximum aggregate size must be from 3/8 to 1 inch. The cementitious material content must be at least 505 pounds per cubic yard if a maximum of 3/8-inch aggregate is used.

Preformed expansion joint filler must comply with ASTM D1751.

Mortar must comply with section 51-1.02F.

Form oil must:

1. Be commercial quality or an equivalent coating

2. Allow the ready release of forms

3. Not discolor the concrete



73-1.02B Detectable Warning Surfaces


A detectable warning surface must be on the Authorized Material List for detectable warning surfaces and must match yellow color no. 33538 of FED-STD-595.


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