Electrochemical studies of steel in cement mortar containing chloride and micro-silica
By Videm, Ketil
Published in Corrosion Science
2007
Abstract
Steel electrodes have been exposed for 3.5 years in cement mortar with and without chloride and ELKEM micro-silica. Corrosion potentials in mortar without Cl- varied between -0.1 and +0.06 V(SCE), indicating passivity. One percentage of cement weight of Cl- reduced the corrosion potentials to about -0.2 V(SCE). Micro-silica in chloride containing mortar increased the severity of corrosion the first year. However, after 2 years exposure reduction of interconnected porosity and increased resistivity caused by 15% micro-silica, raised the corrosion potentials and counteracted chloride-attack. The polarisation resistance was undefined, the apparent values varying with the technique and parameters used.