Ultimate Capacity of Corroded Statically Indeterminate Reinforced Concrete Members

Abstract

The corrosion of steel reinforcement is commonly believed to be the primary cause of structural deterioration of reinforced concrete (RC) structures; as a result of this deterioration, a RC structure can incur a considerable reduction in structural serviceability and safety. Because of their inherent redundancy, statically indeterminate structures develop resistant mechanisms that can potentially assist in delaying the collapse of severely damaged RC structures. In order to experimentally demonstrate these resistant mechanisms, four groups of three two-span continuous RC beam members each were deteriorated using induced corrosion methods and tested to failure under monotonic loads. For control, one group of three RC beams was left uncorroded and similarly load tested. All the RC beam specimens subjected to corrosion demonstrated a significant reduction (a maximum reduction of 55% as compared to the uncorroded control group) of their ultimate capacity. The presence of corrosion induced a transition from flexural failure to anchorage failure in some specimens; despite the induced damage some redistributed structural capacity was observed. Modelling of deterioration effects by the inclusion of different aspects of corrosion was also conducted. Three-dimensional (3D) Finite-Element Method (FEM) models were developed to assess the variation in the mechanical properties of the corroded steel and the reduction in the bond interaction between concrete and steel due to the corrosion of the steel reinforcement. In general, the current 3D FEM models demonstrated a good agreement with the experimental data; however, 3D FEM models that exhibit greater sophistication are necessary to better describe the failure mode of some RC beam specimens when they are associated with local effects.

An Optimized Neuro-Bee Algorithm Approach to Predict the FRP-Concrete Bond Strength of RC Beams

“…The concrete cover may potentially spall as a result of the expansion pressure. In general, such degradation reduces the load carrying capacity of the RC member's or structures and its stiffness [9][10][11]. The escalation of environmental contamination in recent decades has resulted in a substantial increase in corrosion phenomena in RC structures, which has VOLUME X, 2021 resulted in several collapses, particularly in those structures that have not received appropriate maintenance.…”

Resistance of corroded RC beams: Extending fib Model Code 2010 models

“…In order to select a sufficiently wide set of specimens only such tests for beams with transverse reinforcement are studied in the following. To the best of author's knowledge one only work in the literature 19 studies the important case of continuous beams. Existing structures often have continuous supports with a statically indeterminate scheme, hence this is an important field of study.…”

Bond of naturally corroded, plain reinforcing bars in concrete

“…Corrosion affects the structural performance in different ways: 1) the development of corrosion products results in a loss of the steel cross-sectional area; 2) corrosion products occupy a volume larger than uncorroded steel, inducing mechanical pressure on both the bar and the surrounding concrete; and 3) corrosion introduces a layer of corrosion products between the steel-concrete interface. These effects can compromise the function (Fernandez, Herrador, Mar ı, & Bair an, 2016;Malumbela, Alexander, & Moyo, 2009) and structural integrity of the structure Fernandez, Herrador, Mar ı, & Bair an, 2018). In particular, the bond between the steel and surrounding concrete is strongly affected.…”