Manufacture:
Gabions shall be manufactured from a hard drawn steel wire formed into a bi-axial mesh grid by electrically welding the cross wire at every intersection. The weld strength is to be 70% of the ultimate tensile strength of the wire.
ASTM A974-97(2011) Standard Specification for Welded Wire Fabric Gabions and Gabion Mattresses
Mesh Size:
The mesh openings shall be square and of a nominal dimension of 75mm on the grid
Mesh Wire:
The nominal wire diameter shall be either 3.0mm or 4.5mm diameter wire. The tensile strength shall be in the range of 500-770 N/mm2
Corrosion Protection:
Wire shall be Galfan coated (95% Zn/5% Al) ZGF255 spec
AS 4534 Zinc and zinc/aluminium-alloy coatings on steel wire. Class W10 (heavy coating)
Jointing:
Gabions shall be provided with bracing wire and helical spirals for site assembly. The bracing wire shall be of nominal wire diameter of 2.2mm and the helicals of 3.0mm (all in accordance with corrosion protection specified) for final jointing.
Rockfill:
Gabion fill shall be hard and durable and non frost susceptible (rock or stone type) having a minimum dimension not less than the mesh opening and a maximum dimension of 200mm.
Shall comply with AS 2758.4-2000 Aggregate for gabion baskets
and wire mattreses.
Construction:
All rock fill shall be packed tightly with a minimum of voids (final void ratio to be less than 0.3). Bracing wires from front face to rear face, and terminal end panels, to be spaced no further apart than 350mm in both vertical and horizontal directions. Gabions to be filled such that the mesh base of the unit above bears down onto the rock fill of the unit below.
