The effect of flexural cracks is to modify the analysis of reinforcement corrosion because they provide local ingress and partial corrosion product release. In other words, a longitudinal crack on the surface is a measurement of retained expansive pressure in the cover, not an estimate of pit depth. The following calculation is done for flexurally cracked reinforced concrete beams whose tensile reinforcement is defined in terms of a longitudinal coordinate, where the corrosion zone consists of distributed penetration and associated cracking pitting, the steel corrosion consumption is transformed into a free rust expansion, and where a part of mechanically effective corrosion product is decreased near the open flexural cracks before nonlocal splitting demands on the cover are assessed. These calculations are performed for SCB and DN1 beam cases. SCB is a beam that is slightly corroded in the presence of sustained four-point bending and lateral cracking in side covers near lower reinforcement. DN1 is a beam that is highly corroded after three-point bending and bottom-cover splitting prevailed. According to calculations, the maximum corrosion-induced crack widths equal 0.54 mm and 1.34 mm for SCB and DN1 beam cases, respectively, while measured crack widths are 0.56 mm and 1.43 mm correspondingly; thus, the relative differences are -3.6\% and -6.3\%, respectively. The same retained-pressure calculation also explains the transition from side cover cracking in SCB to bottom-cover splitting in DN1. Sensitivity calculations based on transport influence lengths of 20, 60, and 100 mm, flexural crack spacing of 220, 150, and 100 mm, and flexural crack widths of 0.25, 0.49, and 0.64 mm reveal that the critical crack may form elsewhere in the cover compared to the point of the deepest local pit in the case where rust release through flexural cracks is taken into account. It means that the visible corrosion cracking in pre-cracked beams is determined by retained pressure in the rust rather than the maximum local penetration alone.

reinforced concrete,corrosion-induced cracking,flexural cracks,rust retention,nonlocal fracture demand,cover splitting,crack-width prediction,durability assessment