Finite element analyses on the flexural response of post-tensioned concrete bridge girders with corroded tendons in different grouting conditions

Corrosion of prestressing steel significantly impacts the performance of existing prestressed concrete (PC) structures. In post-tensioned (PT) concrete technology, construction defects-such as local voids into the mortar grouting within the ducts-may prompt corrosive phenomena by exposing the strands to potential harmful environment. As a result, the load-carrying capacity of the structures may be severely undermined. This work investigates the influence of corrosion of the prestressing steel on the flexural response of PT concrete bridge girders with defective grouting. Finite element models (FEMs) were calibrated starting from experimental tests on six reduced-scale PT girders with three grouting conditions, namely bonded (B), unbonded (U) and partially bonded (PB), and two initial prestress levels. Different levels of corrosion with increasing severity were considered to study the mutual effects of reduced stress-strain capacity of the strand and different bonding conditions, with emphasis on the girders’ capacity both in terms of global and local response. This study moves towards the capacity assessment of existing prestressed concrete bridge girders with corrosive phenomena affecting the prestressing steel, providing in-sights into the complex evaluations required for corrosion-impacted structural responses.