1/ PVC coating does not improve the gabions resistance to damage from flood debris impact.
Rock impact tends break wires instantly and the thicker the wire the less likely this damage is to occur.
Gabion1 recommend using the thicker 3/16th welded mesh gabions for erosion control
CalTrans report states that,
State of California Gabion mesh corrosion report
PVC-coated wires usually performed better than zinc-coated wires in severe, natural exposures. They showed very little to no strength loss for about 13 years, although wires were in early states of corrosion. Because the bond between PVC and the underlying metal broke after cycling through temperature changes (daily or seasonally), a capillary space formed, where electrolyte migrated, and then corrosion started. In continued severe exposures, we expect that PVC-coated wires will continue to corrode, possibly disintegrating within the confined PVC sheath, or expanding and breaking the PVC as corrosion compounds form.
PVC has a smooth and shiny surface when it is newly manufactured. After about 3 to 5 years of exposure to sunlight, PVC photo-degraded, and it became dull and got chalky. Simply described, photons (incident light) displaced chloride ions in surface molecules. Plasticizers may be added to PVC for flexibility. After about 7 years at site 7, the surfaces of sun-exposed PVC coating developed cracks. As plasticizer compounds volatilized, PVC coating shrank and cracked. Among the sites where test panels were submerged in either mud or water, PVC did not become dull, like sun-exposed PVC. Instead, PVC hardened and often discolored by reacting with its surroundings.
Once the PVC coating is damaged, the gabion then relies on the Galfan coating to prevent corrosion.
In erosion control applications the PVC is often chipped off and damaged by flood debris
The images below are of PVC mesh that was damaged in transit, before gabion assembly and prior to the rocks being added.
Want more information on gabion box manufacturer? Click the link below to contact us.