Evaluation of ultimate capacity of corrosion damaged reinforced concrete beam-columns using nonlinear sectional analysis

Simplified Seismic Evaluation of Aged Corrosion Damaged Reinforced Concrete Bridge Columns as Part of Simplified Semi-Quantitative Assessment Framework

“…Nonlinear Sectional Analysis (NLSA) is the basis for evaluating the columns' performance under corrosion and ultimate seismic loads as part of evaluation-ULS only in high-risk seismic zones [4]. The evaluation of the column structural performance under combined reinforcement corrosion and ultimate loads and the evaluation of the column structural performance under combined reinforcement corrosion and traffic loads are presented in Mohammed et al [21], [22].…”

“…Accurate measurement of the maximum reduction of rebar diameter is then determined for each sample. If a constant corrosion rate is assumed, the time elapsed to generate the measured diameter reduction in the reinforcing bars is then found using the data of different samples and Faraday's law [22]. Using the evaluated reinforcement corrosion parameters and empirical formulae (for example, see Lay and Schiebl [24] and Cairns et al [25]), the loss of strength and ductility of the reinforcement as a result of pitting corrosion can be estimated.…”

“…The proposed SNLSA is based on four main steps: (i) the Semi-Quantitative Assessment Framework (SQAF) [4]; (ii) the simplified Nonlinear Sectional Analysis (NLSA) [22]; (iii) the dynamic inelastic analysis of plane RC structures (DRAIN-RC) [27]- [28]; and, (iv) Takeda hysteretic model [29]. Corrosion-induced damage on the steel reinforcement is considered by decreasing the cross-sectional area and ductility as a function of corrosion, whereas damage in the concrete is incorporated by removing the concrete cover (spalling) and/or removing one or more ties, with the ensuing decrease in concrete confinement.…”

“…The NLSA model incorporates corrosion-induced damage by reducing the steel cross-section and ductility, removing the concrete cover (simulating spalling), accounting for the loss of local bond, removing lateral ties/ stirrups (simulating tie fracture due to corrosion), and reducing concrete confinement as a result of tie loss in corrosiondamaged zones. The model can simulate the mechanical behavior of corrosion-damaged RC beam columns at the section level for all loading situations, including pure flexure, pure axial load, or any combination of axial and flexural stresses [22].…”

“…In the Nonlinear Sectional Analysis (NLSA), modeling the effects of corrosion on the reinforcement, the concrete section, and the concrete-and-steel reinforcement composite action is presented in detail by Mohammed et al [22]. The three major effects of corrosion on the state of damage are (i) the reduction of cross-sectional area and ductility of the reinforcement; (ii) loss of concrete cover; and (iii) the local bond loss of tensile steel reinforcement.…”