Environmental influence on mesh corrosion in underground coal mines

The effect of corrosion on different steel mesh types was examined in a Controlled Mine Environment laboratory which recreated underground mine environmental conditions. Corrosion rates of mesh at different testing conditions were calculated and weld strengths of the corroded mesh were examined. Mesh specimens in ‘dry’ conditions had no significant corrosion effects over 12 weeks. However, ‘wet-dry cycle’ mesh specimens exhibited significant corrosion rapidly, with estimated corrosion rates of around 0.01 mm/yr for galvanised mesh, whether sprayed once or three times daily, 0.70 mm/yr for three times daily sprayed black mesh and 0.48 mm/yr for once daily sprayed black mesh. The mesh corrosion mechanism was dramatically changed by wet-dry cycle. The results are indicative of the behaviour of installed mesh.