A corrosion model for the interpretation of cyclic behavior of reinforced concrete sections

Abstract

A generalized cyclic steel model characterized by isotropic and kinematic hardening, inelastic buckling in compression and corrosion of rebars in reinforced concrete (RC) structures is presented. The model has been implemented in a fiber code, to perform seismic analyses of RC sections. The model is particularly accurate with respect to experimental cyclic behavior of rebars with buckling in compression when the strain does not exceed 1.5%. Twelve configurations of RC cross sections were selected as case studies for three geometries and different steel arrangements, assumed representative of RC columns or bridge piers (in a suitable scale). Each section was subjected to two groups of cyclic curvature histories representative of severe seismic loads, not far from collapse. Different axial loads and corrosion percentages (no corrosion, moderate, or high) have been selected to perform cyclic parametric analyses. One of the cases was taken from an experimental test on columns, deriving also steel characteristics used in all numerical cases. The results of the comparison among RC sections have been discussed. Numerical results show that the maximum compressive strain for steel rebars is always smaller than 1.5%, therefore the proposed steel model is accurate and represents a valid tool for structural assessment. Corrosion reduces RC section capacity, affecting various rebar mechanical characteristics, in particular buckling behavior.

IMPAβ: Incremental Modal Pushover Analysis for Bridges

“…The Bridges were modeled by using the finite element (FE) software SAP2000 NL, v. 21 [43]; the 3D numerical models are shown in Figure 9a,b,c and were modeled according to the structural scheme already used in previous studies [44].…”

“…In order to validate the generalization of IMPAβ for bridges, statistical analyses of results based on responses obtained by using the single response spectra of the accelerograms used for IDA, the effects of the variation of the seismic input with intensity, the asynchronous seismic motion [42,43], near fault seismic input and all the different bridge configurations (i.e., deck shape and sections, constraints, bridge piers and bridge length) are in progress.…”

Finite Element Analysis of Reinforced Concrete Bridge Piers Including a Flexure-Shear Interaction Model

“…Therefore, the resulting structures where conceived to respond in the elastic range, leaving a false sense of security that the actual resistances (well beyond the nominal ones considered in the design process) would be assured by the adopted safety coefficients and by the inelastic behavior of materials and structures. On the contrary, the lack of a hierarchy of strengths that would be lately assured by the implementation, in modern codes, of capacity design principles, would not prevent the occurrence of non-ductile failure modes reducing the extent of the inelastic response [3][4][5][6].…”

Regional Seismic Damage Simulation of Corroded RC Frame Structures: A Case Study of Shenzhen City

“…Furthermore, a simplified hysteretic model is used to simulate the performance of corroded RC frame structures. Some mechanisms, such as post-yielding buckling [62], can also affect the performance deterioration of RC frame structures, which require further investigation in future studies.…”