Influence of White Aluminum Dross on the Corrosion Resistance of Reinforcement Carbon Steel in Simulated Concrete Pore Solution

Recent research in concrete technology now focuses on partial replacement of cement using cost-effective, eco-friendly and sustainable wastes and admixtures. The effect of white aluminum dross (Al-D) at 0%, 5%, 10%, 15%, 20% and 25% weight concentration on the corrosion resistance of low carbon steel in simulated concrete pore solution was studied with potentiodynamic polarization technique and open circuit potential (OCP) measurement. Optical microscopy was used to analyze and compare the surface morphology of the steel specimens before and after the corrosion test. Results from electrochemical test showed Al-D in concrete admixture mildly increases the corrosion rate of the carbon steel with respect to Al-D concentration. Corrosion rate values of 3.00 × 102, 3.41 × 102 and 8.39 × 102 were obtained at 0%, 5% and 25% Al-D. Cathodic shift in corrosion potential was observed due to selective deterioration of the steel. However, potentiostatic data show the presence of Al-D extends the passivation range of the carbon steel, improving its pitting corrosion. OCP plots with and without shift significantly to positive values with respect to exposure time signifying formation of protective oxide on the carbon steel. Severe morphological deterioration in the form of corrosion pits are visible on steel surface from concrete pore electrolyte at 0% Al-D. Fewer and comparatively smaller corrosion pits are visible on the morphology of the steel from 5% Al-D pore electrolyte. The relative size of the corrosion pits decreased further from observation of the steel from pore solution at 25% Al-D. © 2018, Springer Nature Switzerland AG.