§ 607S.3. Materials

A.

Precast Concrete Units.

Concrete units shall be precast concrete blocks with a 12 to 16 inch (300 to 400 mm) module and shall be 4 or 6 inches (100 or 150 mm) thick, as indicated on the Drawings. The concrete shall attain a minimum 28-day compressive strength of 4000 psi (27.5 megaPascals) in conformance to Class S of Standard Specification Item No. 403, "Concrete for Structures". Each precast concrete unit will weigh at least 30 pounds per cubic foot (480 kilograms per cubic meter) and the open void area will range from 20 to 25 percent.

The Filter/carrier fabric shall conform to Item No. 620S, "Filter Fabric". The fabric shall be of sufficient strength to support not less than 1 ½ times the weight (mass) of the mat when slung by lifting at both ends.

B.

GeoGrid

GeoGrid shall consist of polypropylene base and shall be: 1) resistant to all natural occurring alkaline and acidic soil conditions, 2) resistant to attack by bacteria and fungi, and 3) ultraviolet stable. The plastic grid shall have a thermal stability range from -60o F to 175 o F (-50°C to 80 °C) and a Melt Index of 0.2 grams/10 minutes.

Geogrid shall have a density between 75 to 106 pounds per cubic feet (1.2 to 1.7 megagrams per cubic meter) and thickness shall be 0.15 to 0.25 inch (4 to 6 mm). Tensile strength shall be 860 to 1230 pounds per square foot (41 to 59 mPa) across the roll.

C.

Earth Reinforcement System

A patented earth reinforcement system shall consist of interlocking precast reinforced concrete units of the size, shape and texture indicated on the Drawings, placed on a concrete foundation. All precast concrete shall be Class S, with a minimum 28 day compressive strength of 4000 psi (27.5 mPa), cast-in-place concrete shall be Class A, conforming to Item No. 403, "Concrete for Structures". All joints shall be caulked and protected with a filter fabric as indicated on the Drawings. All reinforcing steel shall conform to Item No. 406, "Reinforcing Steel". All tie back and reinforcing mesh shall be in accordance with manufacturer's recommendations.

Filter fabric to conform to Item No. 620S, "Filter Fabric.

D.

Gabions and Revet Mattresses

Gabions shall be assembled and placed as directed on the Drawings in accordance with Standard Specification Item No. 594S, " Gabions and Revet Mattresses".

E.

Additional Materials and Methods

In addition to those systems described above, the following items may be used in combinations or separately, as indicated on the Drawings:

Standard Specification Subject	Item No
Concrete for Structures	403S
Concrete Structures	410
Riprap for Slope Protection	591S
Concrete Retards	593S
Sodding for Slope Stabilization	602S
Seeding for Slope Stabilization	604S
Salvaging and Placing Topsoil	601S
Soil Retention Blanket	605S
Filter Fabric	620S
Dry Stack Wall (DS)	623S
Rock Berm (RB)	639S
Mortared Rock Wall (RW)	640S

 

Additional Products not mentioned herein may be indicated on the Drawings.