STUDY ON CORROSION PROTECTION PERFORMANCE OF MORTAR COVER MEHTOD USING CONDUCTIVITY MORTAR IN CONBINATION WITH CATHODIC PROTECTION

Abstract

 Ordinally, for corrosion protection in marine steel structures, cathodic protection methods is applied to M.L.W.L. or less, and coating protection methods is applied to L.W.L. -1.0m or more. Therefore, we considered to expand the effective range of cathodic protection in under-seawater to the coating protection area by applied high-conductivity mortar mixed with carbon as a covering material. it can reduce the resistance to 1/100 compared to ordinary concrete and confirmed that it can be protected with suppling 1mA/m² or more in underwater environment and 100 mA/m² or more in dry environment as corrosion protection current. Sufficient corrosion protection performance was confirmed at a range of L.W.L. +235 cm or less from result of 3.5 years-exposure test in marine environment.