Geotextile Liners Placed Behind Gabions to Prevent Soil Loss Effectively

• Geotextile Liners Placed Behind Gabions to Prevent Soil Loss Effectively

We supply woven wire mesh gabions filled with rock for gabion basket wall construction with geotextile fabric. The gabions are manufactured to the dimensions, lines, and grades shown in the project plans or as specified by the engineer. These gabions comply with ASTM A975.

Woven Mesh Gabions

Zinc-Coated Wire Requirements

All wire tests must be completed before mesh manufacturing.

• Tensile strength: Gabion wire and lacing wire shall have a maximum tensile strength of 75,000 psi (515 MPa) in accordance with ASTM A641/A641M.

• Elongation: Tested on a sample at least 12 in. (30 cm) long, with elongation not less than 12% in accordance with ASTM A370.

• Zinc coating: Zinc coating shall meet ASTM A641/A641M, Class III soft temper coating requirements.

• Adhesion of zinc coating: When the wire is wrapped six turns around a mandrel four times the wire diameter, the zinc coating shall not flake or crack when rubbed by bare fingers, in accordance with ASTM A641/A641M.

PVC Coating Requirements

PVC-coated gabion mesh shall meet the following requirements:

• Specific gravity: 81-84 pcf (1.30-1.35 kg/dm³), according to ASTM D792, Table 1

• Hardness: 50 to 60 Shore D, according to ASTM D2240

• Tensile strength: Minimum 2,985 psi (20.6 MPa), according to ASTM D412

• Modulus of elasticity: Minimum 2,700 psi (18.6 MPa), according to ASTM D412

• Abrasion resistance: Weight loss less than 12%, according to ASTM D1242

• Heat aging test: Before UV and abrasion degradation, PVC coating shall have a projected durability life of 69 years according to UL 746B

• Standard PVC coating color: Gray

Accelerated Aging Test Requirements

• Salt spray test: 3,000 hours, ASTM B117

• UV exposure test: 3,000 hours at 145°F (63°C), ASTM D1499 and ASTM G152

• Brittleness temperature: No higher than 15°F (-9°C), or lower if specified by the purchaser, according to ASTM D746

PVC Coating Properties After Aging Tests

• No cracking, stripping, air bubbles, or major color change

• Specific gravity variation shall not exceed 6%

• Hardness variation shall not exceed 10%

• Tensile strength variation shall not exceed 25%

• Modulus of elasticity variation shall not exceed 25%

• Abrasion resistance variation shall not exceed 10%

• Brittleness temperature shall not exceed +64°F (+18°C)

Galvanized and PVC Coated Wire Mesh Gabions (8 x 10 Mesh Type)

• PVC coating thickness: Nominal 0.02 in. (0.5 mm), minimum 0.015 in. (0.38 mm)

• Mesh wire diameter: 0.106 in. (2.70 mm) internal, 0.146 in. (3.70 mm) external

• Selvedge wire diameter: 0.134 in. (3.40 mm) internal, 0.174 in. (4.40 mm) external

• Mesh opening: Nominal dimension D = 3.25 in. (83 mm)

Galvanized and PVC Coated Lacing Wire and Internal Stiffeners

• PVC coating thickness: Nominal 0.02 in. (0.5 mm), minimum 0.015 in. (0.38 mm)

• Lacing wire diameter: 0.087 in. (2.20 mm) internal, 0.127 in. (3.20 mm) external

• Cross tie/stiffener wire diameter: 0.087 in. (2.20 mm) internal, 0.127 in. (3.20 mm) external

• Preformed stiffener diameter: 0.134 in. (3.40 mm) internal, 0.174 in. (4.40 mm) external

Steel Mesh Properties

• Mesh tensile strength: Minimum 2,900 lb/ft (42.3 kN/m), tested according to ASTM A975 Section 13.1.1

• Punch test resistance: Minimum 5,300 lb (23.6 kN/m), tested according to ASTM A975 Section 13.1.4

• Connection to selvedges: Minimum 1,200 lb/ft (17.5 kN/m), tested according to ASTM A975

Spenax Fasteners (Overlapping Fasteners)

Stainless steel overlapping fasteners may be used instead of, or together with, lacing wire for gabion basket assembly and installation.

• Fastener spacing: Nominal 4 in. (100 mm), not exceeding 6 in. (150 mm)

• Pull-apart resistance: Based on 1,200 lb/ft (17.5 kN/m) for galvanized and PVC-coated mesh, according to ASTM A975 Section 13.1.2

• Compliance testing: Fasteners used in the field shall comply with ASTM A975 Section 13.1.2.2 Pull-Apart Resistance

• Field test performance: Average maximum resistance shall not be lower than 90% of the certified resistance

• Fastener material: Stainless steel, 0.120 in. (3.05 mm) diameter, ASTM A313/A313M, Type 302, Class I

• Tensile strength: 222,000 to 253,000 psi (1530-1744 MPa), according to ASTM A313 Table 5

• Proper overlap after closure: Nominal 1 in. (25 mm)

Tolerances

• Wire coating: Zinc coating shall comply with ASTM A641/A641M, Class III soft temper coating

• Gabion dimensions: ±5% on length, width, and height

• Mesh opening tolerance: Hexagonal double-twisted mesh opening tolerance shall not exceed ±10% of nominal dimension D

Standard Unit Size

• Mesh type: 8 x 10

• Nominal dimension D: 3.25 in. (83 mm)

Fabrication

• Gabions shall be manufactured and shipped with all components mechanically connected at the factory. The front, base, back, and lid shall be woven into one unit. The ends and diaphragms shall be factory connected to the base. All perimeter edges of the mesh forming the basket and lid shall be selvedged with larger diameter wire.

• The gabion shall be divided into cells by diaphragms placed at about 3 ft (1 m) centers. These diaphragms shall be secured to the base so no additional lacing is required at the jobsite.

Rock Fill Requirements

The rock used for gabion baskets shall be hard, durable, and angular to round in shape. The rock shall resist disintegration from water exposure and weathering during the service life of the structure.

• Rock size range: 4 in. (0.10 m) to 8 in. (0.20 m)

• Size tolerance: Up to 5% oversize and 5% undersize rock is allowed, but not on exposed surfaces

• Placement requirement: Rock size shall allow at least three layers of stone when filling the gabions

Supply and Delivery of Geotextile Filter Fabric

We supply geotextile filter fabric made from woven polypropylene for filtration, separation, and soil stabilization applications. The geotextile filter fabric shall meet or exceed the specified requirements in full. It shall be a pervious polymer sheet with a minimum sheet width of 5.0 m and shall be protected against ultraviolet degradation. Production and quality control shall follow ISO 9001 standards.

Delivery Requirements for Geotextile Filter Fabric

• Geotextiles shall be delivered in rolls with a minimum width of 5.00 m. Each roll shall have a minimum length of 200 m.
  

• Geotextile rolls shall be delivered in packaging suitable for protecting the material from ultraviolet light degradation.

Transportation and Storage Requirements

• During shipment, land transportation, and storage, the geotextile filter fabric shall be protected from direct sunlight, ultraviolet rays, and temperatures above 60°C.

• Geotextiles shall also be protected at all times from physical damage and chemical damage to maintain product quality during handling and storage.