Time‐dependent cyclic behavior of reinforced concrete bridge columns under chlorides‐induced corrosion and rebars buckling

Abstract

This study presents the results of a refined numerical investigation meant at understanding the time‐dependent cyclic behavior of reinforced concrete (RC) bridge columns under chlorides‐induced corrosion. The chloride ingress in the cross‐section of the bridge column is simulated, taking into account the effects of temperature, humidity, aging, and corrosion‐induced cover cracking. Once the partial differential equations governing such multiphysics problem are solved through the finite‐element method, the loss of reinforcement steel bars cross‐section is calculated based on the estimated corrosion current density. The nonlinear cyclic response of the RC bridge column under corrosion is, thus, determined by discretizing its cross‐sections into several unidirectional fibers. In particular, the nonlinear modeling of the corroded longitudinal rebars exploits a novel proposal for the estimation of the ultimate strain in tension and also accounts for buckling under compression. A parametric numerical study is finally conducted for a real case study to unfold the role of corrosion pattern and buckling mode of the longitudinal rebars on the time variation of capacity and ductility of RC bridge columns.

Maintenance interventions period of existing RC motorway viaducts located in moderate/high seismicity zones

“…Considering an initial value of cover thickness equal to 25 mm, the iterative process has been developed for different concrete type. In this work the cover thickness of the longitudinal reinforcements is calculated considering the presence of the stirrups [47].…”

The greenway for bridge column rehabilitation: a comparison between different techniques based on multi-criteria decision analysis

“…7. Figure 8a shows the time-dependent evolution of the chloride-induced corrosion, expressed as the loss of reinforcement section or the ratio between corroded section A pt and original bar section A' s , predicted from multiphysics FE-based simulations for each intervention methodology [44]. As regards the first option, the replacement of the pier with a new one designed as the original without providing for a regulatory adaptation, there will be a loss of the reinforcement area after 50 years of about 11%.…”

Fragility analysis of existing prestressed concrete bridges under traffic loads according to new Italian guidelines

“…Corrosion of reinforcing steel may be addressed as one of the most popular causes of damage to reinforced concrete and prestressed concrete (PC) structural members. [1][2][3][4] In this regard, in the last decades seismic performance of bridges has been extensively studied, involving a number of topics such as nonlinear modeling, performance-based design, probabilistic assessment, and structural fragility. [5][6][7][8] During the last few years, a growing interest has been paid in firstorder reliability methods for safety assessment of existing bridges.…”