Gabion Cages are wire containers made of hexagonal wire netting. Wire diameter varies with the hexagonal nettings. For hexagonal wire netting with no pvc coating, the wire diameter ranges from 2.0mm to 4.0mm. For those PVC coated hexagonal wire netting, the outside diameter ranges from 3.0mm to 4.0mm. The wire of the outside frame edge is one wire gauge thicker than the wire used for hexagonal wire netting.
1. Heavily Galvanized Gabions
Wire shall be to BS 1052/1980 “Mild Steel Wire”, having an average tensile strength of 38-50 kg/mm² before PVC coating and fabrication of the netting.
Wire shall be Heavily Galvanized to BS 443/1982 “Galvanized Coating on Wire”, that is to say the minimum weight of zinc coating shall be according to the table below:
When the wire is wrapped six times around four wire diameter size mandrell, the zinc coating shall not flake or crack to the extent that any Zinc can be removed by rubbing with bare fingers.
2. Heavily Galvanized and PVC Coated Gabions
In addition to heavy galvanizing as described, the wire shall be have extruded onto it a coating of poly vinyl chloride, otherwise referred to as PVC. The coating shall be grey in colour, shall nowhere be less than 0.40mm in thickness and shall be capable of resisting deleterious effects of naturals weather exposure, immersion in salt water and shall not shown any material difference in it’s initial characteristics.
The maximum penetration of corrosion of the wire core from a square cut end shall not be greater than 25mmwhen the specimen has been immersed for 2000 hours in a 50% solution of HCL (Hydrochloric Acid 12BE).
