Impact of cracks on distribution of chloride-induced reinforcement corrosion

Abstract

Surface crack width is regulated in codes to limit corrosion of reinforcement bars in concrete. However, the influence of surface crack width on corrosion damages is not directly inferable from previous research.In this work, data on corroded cracked concrete specimens in chloride environments was compiled. Detailed information was included, such as crack and pit locations, local corrosion pattern, etc. Five hypotheses on the influence of transversal cracks on corrosion damage were formulated, and statistical methods were used to test them on the dataset.Transversal cracks were good indicators of the position of corrosion pits. The corrosion rate of the pit increased in proximity of a crack. With time, pits grew in depth at a slower rate but increased in number. No clear correlation between surface crack width and corrosion damage was found. Results point out discrepancies in the collected data, arguing for the need of well-defined procedures for assessing crack and corrosion damage.Further, the statistical treatment allowed for identification of bias in existing data, which was used as a research planning tool to provide guidance on the design of additional experiments. Thus, recommendations for future experimental work required to reduce the bias are given.

An Assessment of the Structural Performance of Rebar-Corroded Reinforced Concrete Beam Members

“…Typically, corrosion is caused by an incorporation into the concrete mixture [12], the attack of chloride ions penetrating via diffusion from the outside [13][14][15][16][17][18][19], the carbonation of the concrete cover [17,18,20], or a combination of these issues [21][22][23][24][25][26][27][28][29]. As corrosion progresses, the expansive displacement at the interface generated by accumulating rust products causes tensile stress in the hoop direction within the concrete cover [30], leading to radial splitting cracks in the cover concrete [11,16,22,28,[31][32][33][34][35][36][37][38].…”