Meso-scale modeling of concrete cracking induced by 3D corrosion expansion of helical strands

Abstract

A meso-scale numerical model is established to simulate concrete cracking induced by the three-dimensional (3D) corrosion expansion of helical strands in the present study. A 3D corrosion expansion model is proposed to consider the longitudinal helix shape and transverse flower-like shape of the strand. The concrete in the model is considered as a three-phase composite material consisting of a mortar matrix, aggregate, and interfacial transition zones (ITZ) between the mortar matrix and aggregate. The rationality of the proposed model is validated, and the effects of the space helix structure and the lay length of the strand on corrosion-induced cracking are discussed. The results indicate that considering the space helix structure of a strand can effectively improve the prediction accuracy of strand corrosion-induced concrete cracking. The change in strand lay length has little effect on the critical corrosion loss of the initial damage occurrence. The critical corrosion loss at cover cracking increases with increasing strand lay length, whereas the corrosion-induced crack width decreases with increasing strand lay length.