Experimental study of corrosion-caused corner cracking using digital image correlation

Abstract

Cover cracking caused by rebar corrosion is one of the most predominant deterioration problems of reinforced concrete structures. Cracking types include three main modes: cover spalling, cover delamination and corner cracking. However, despite being one of the most common cracking problems, corner cracking is seldom studied by way of experimental tests. In this paper, the mechanism and process of corner cracking are experimentally studied using accelerated corrosion tests together with digital image correlation (DIC). The entire process of corner cracking and the rotation phenomenon of corner cracking are experimentally recorded. Displacements around the steel/concrete interface are measured using the DIC technique. Concrete strain around the rebar is also measured with strain gauges. Bulging and crack mouth opening displacements on the cover surface are quantitatively analyzed. The extent of corrosion around the corroded rebars is recorded.