Steel reinforcement corrosion in concrete – an overview of some fundamentals

Professor Brian Cherry was always been a firm believer in understanding first the fundamentals of any aspects of corrosion science, then the mechanisms, before embarking on the engineering of solutions to the management of materials corrosion. So it was with steel-reinforced concrete. This paper endeavours to walk a reader through the fundamental and mechanistic aspects of the excellent protection afforded to steel reinforcement by concrete (including electrochemistry), corrosion of steel reinforcement [including uniform (microcell/minicell) and pitting (macrocell) aspects, corrosion products composition and development], chloride-induced corrosion mechanisms (passive film breakdown/pit initiation, metastable pitting, pit growth/propagation, chemical conditions within propagating pits and reinforcing steel quality effects), carbonation-induced corrosion mechanisms, leaching induced corrosion of reinforcement and reinforcing steel stray current corrosion and interference.