Galfan mattress are manufactured from 95% Zn and 5% Al coated double twist hexagonal wire mesh, and are normally supplied 6 x 2 m dimensions with a thickness less than 500mm. Mattress are filled with stones on site to create a flexible, permeable and monolithic structure for use in river and canal bank protection works as well as erosion control and scour protection of slopes.
The galfan coating provides improved corrosion resistance in comparison to a conventional galvanized coating, combining, in effect, the passive corrosion inhibition of aluminum oxidation with the active and passive effects of zinc. Galfan (95% zinc, 5% aluminium) has proven to be 2 to 3 times more corrosive resistant than the same thickness of hot dipped galvanized. Depending on the environment, it may take 50 years to 150 years for 5% rust to show on the surface of galfan when above ground.
Mattress shall be manufactured with a 6 x 8 mesh type having a nominal mesh opening of 64 x 83 mm (2.5 by 3.25 in.). Tolerances on the mesh opening shall not exceed ± 10% on the nominal dimension D values.
Typical mesh wire, selvedge wire and lacing wire group
2.00 mm, 2.70 mm, 2.00 mm
2.20 mm, 2.70 mm, 2.20 mm
Minimum zinc coating weight of galfan mattress wire
2.00 mm ≥ 215 g/㎡
2.20 mm ≥ 230 g/㎡
2.70 mm ≥ 245 g/㎡
Mesh Opening 60 x 80 mm
Mattress wire diameter tolerance
2.00 mm ± 0.05 mm
2.20 mm ± 0.06 mm
2.70 mm ± 0.06 mm
Typical mattress size (L x W x H)
3 x 2 x 0.3 m with 2 diaphragms
4 x 2 x 0.3 m with 3 diaphragms
5 x 2 x 0.3 m with 4 diaphragms
6 x 2 x 0.3 m with 5 diaphragms
Width and length of the mattress as manufactured shall not differ more than ± 5%, and the height shall not differ more than ± 10% from the ordered size prior to filling.
Gabion Size 2 x 1 x 1 m
Gabion and mattress shall be manufactured with all components mechanically connected at the production facility with the exception of the mattress lid which is produced separately from the base. All gabion and mattress shall be supplied in the collapsed form, either folded and bundled or rolled, for shipping.
Packing of Mattress