Incorporation of pre-existing longitudinal cracks in finite element analyses of corroded reinforced concrete beams failing in anchorage

Transportation infrastructure is of fundamental importance and must be regularly assessed to ensure its safety and serviceability. The assessment of ageing reinforced concrete bridge stock may need to consider corrosion and cracks, as the likelihood of deterioration increases with age. This work accordingly investigates the incorporation of pre-existing anchorage zone corrosion cracks into the finite element modelling of reinforced concrete beam structural behaviour. Three methods of accounting for cracks were applied: (1) modifying the bond stress-slip relation, (2) weakening elements at the position of the crack, and (3) weakened discrete crack elements. The results show that modifying the bond stress-slip relation results in accurate predictions of the ultimate capacity when one-dimensional reinforcement bars are used in the model. Weakening elements at the position of the crack provides reasonable results when the anchorage is modelled with three-dimensional reinforcement bars and a frictional bond model. The implementation of discrete cracks was found to be unsuitable for the studied load situation, as compressive stresses formed perpendicular to the crack. It was concluded that the capacity of the studied case could be well estimated based on visual measurements, without knowledge of the exact corrosion level.

Automated summary

Transportation infrastructure, especially ageing reinforced concrete bridges, must be regularly assessed for safety and serviceability due to corrosion and cracks. This study investigates the effects of pre-existing anchorage zone corrosion cracks on reinforced concrete beam structural behavior through finite element modeling. Three methods of accounting for cracks were applied, with modifications to bond stress-slip relation showing accurate predictions for ultimate capacity in certain reinforcement scenarios. Visual measurements were found to be sufficient for estimating the bridge's capacity without exact knowledge of corrosion level.