Long‐term seismic performance of reinforced concrete bridges under steel reinforcement corrosion due to chloride attack

Abstract

SUMMARY This work presents a new seismic evaluation methodology for corroded reinforced concrete bridges on the basis of nonlinear static pushover analysis. Corrosion of steel reinforcement by chloride attack is considered. At the material level, the effects of corrosion are considered by modeling the degradation of the mechanical properties of steel reinforcement, softening of cover concrete under compression, degradation of core concrete due to confinement steel corrosion, and reduction of bond strength between concrete and steel reinforcement. At the structural level, the effects of corrosion on both flexural behavior and shear behavior, and their interaction are considered. Eleven bridges of various structural types in Taiwan that are located within 6.5 km of their nearest coastline are analyzed to identify their long‐term seismic performance. Relationships between the yield and collapse peak ground accelerations (PGAs), and service time and corrosion level are established for each bridge. Analysis results show that chloride corrosion starts in 2–32 years. The transverse steel reinforcement typically starts corroding before the longitudinal steel reinforcement, as the former has a thicker cover. Research results show that collapse PGA reduces by 0.94% or 1.23% per 10 years when the mean value plus 1 or 2 standard deviation of the collapse PGA values are considered, respectively. Therefore, we suggest increasing the design PGA from 4.70% to 6.15% for a bridge adjacent to a coastline to ensure adequate long‐term seismic performance for 50 years, the typical design life span of a regular bridge. Copyright © 2013 John Wiley & Sons, Ltd.

Experimental Investigation into Corrosion Effect on Mechanical Properties of High Strength Steel Bars under Dynamic Loadings

“…Meanwhile, the yield plateau shortens or even disappears [2,3]. Empirical formulas have been proposed to evaluate the yield and ultimate strengths of corroded reinforcing bars [4,5], and the mathematical models of stress-strain relationship for corroded rebars in different environment condition have also been established [6][7][8][9][10].…”

The corrosion of stirrups and its effect on the seismic fragility of a corroded reinforced concrete column

“…Ou et al [4], Saether and Sand [5] and many other investigators have looked into how corroded RC can be numerically simulated with various finite element analysis software and different approaches. This study utilizes the widely available nonlinear finite element modelling software Abaqus version 6.10.1, which enjoys a great reputation for handling problems with extensive plasticity using a smart solver with automatic increment [6].…”

“…Different kinds of modification factors were proposed to account for the stiffness degradation of the cracked concrete. Ou et al [4] proposed a softening effect coefficient to account for the softening effect of cracking concrete, as follows: 0.9…”

A Parameter Ascertainment Method for the Skeleton Curve of Corroded Reinforcement Concrete Members with Flexure and Compression

“…An external current method [15] was utilized to induce corrosion in the specimens. e specimens were immersed in a water tank containing 3%-5% NaCl solution.…”

“…During the entire service life of the RC structure, the continuous penetration of harmful ions induces cracking and spalling of the concrete cover [1][2][3], degradation of the bond strength [4][5][6][7], and decrease of the material strength [8][9][10][11][12]. In seismic-prone regions, the corrosion damage of the structures would reduce their lateral load-resisting capacity in a seismic event significantly [13][14][15][16].…”