Non-uniformity of Porous Band in Steel-Concrete Interface and Its Influence on Formation of Corrosion Products

Abstract

Steel-concrete interface microstructure plays an important role in the process of corrosion and concrete cover cracking. In this paper, porous band in the steel-concrete interface is quantitatively investigated using Backscattered electron (BSE) imaging. Corrosion of steel is induced by using impressed current, and then corrosion products at the porous band are quantitatively measured using BSE imaging. The results show that both porous band and corrosion products are non-uniformly distributed around steel bar surface. The non-uniform distribution of corrosion products is in line with that of porous band, suggesting that the non-uniformity of corrosion products layer is due to the porous band in the steel-concrete interface. The results also show that the thickness of corrosion products layer at the interface is also significantly affected by that of porous band.