Prediction for lateral deformation capacity of corroded reinforced concrete columns

Abstract

The deformation capacities of columns, which are the main lateral force-resisting elements of reinforced concrete (RC) structures, have been the subject of great interest with the development of performance/displacement-based seismic design. However, deterioration due to chloride-induced corrosion causes a significant reduction in the seismic performance of RC columns. Although numerous investigations have focused on the deformation capacity of columns with corroded rebars and various strengthening measures have been proposed, little attention was paid to evaluating the contribution of each deformation component to the tip displacement under corrosion (i.e., bending, shear, and longitudinal bar slip at the column footing), which plays an important role in investigating and explaining the failure mechanisms of columns. This paper presents a computational prediction model to estimate the deformation capacity of RC columns with corroded rebars, and the contributions of bending and bar slip at the column footing are mainly considered in this model due to the negligible contribution of the shear deformation component for columns subjected to flexural failure mode. The calculation results obtained by the prediction model are comparedwith the quasistatic test results of both noncorroded and corroded RC columns. It turns out that the prediction model simulates the deformation capacity of RC columns with corroded rebars reasonably well considering its simplicity and computational efficiency, and it can be used for time-variant capacity estimates for the lifetime seismic design and fragility assessment of RC columns exposed to corrosion.

Seismic behavior of corroded reinforced concrete column joints under low-cyclic repeated loading

“…In line with previous experiments, numerical models have also been established to simulate governing structural response [28]. Li et al [7] also proposed a computational prediction model to estimate the deformation capacity of columns with corroded rebars, and the contributions of bending and bar slip at the column footing were mainly considered in the model. An advanced modeling technique is developed to model the nonlinear cyclic response of circular RC columns using fiber-based section discretization method [29].…”

“…Numerical simulation results were presented to reproduce the whole process of concrete corrosion and deterioration by reliability-based frameworks [3] and finite element methods with rust introduced as interface between steel and concrete [4]. It is noteworthy that chloride-induced erosion [5], dry-wet cycle and concrete carbonization are considered to the primary factors causing reinforcement corrosion [6] and making concrete structure undergo further deterioration when the structure is located at marine environment [7] or in region where deicing slats are heavily used [8,9]. In addition, corrosion of reinforcing bars will result in deterioration of mechanical properties of steel bars, bond-slip performance between steel bars and concrete, the cross section damage of concrete members and the decreasing of bearing capacity and deformation capacity of structures, which will even cause the destruction of buildings and endanger people safety [10].…”

“…Effectiveness of fiber-reinforced polymer in reducing corrosion was also investigated [35], especially in marine environment [36] and seismic design of structures [37,38]. It is worth mentioning that although many scholars have done numerous investigations on the seismic performance of corroded RC columns, the research field is mainly focused on experimental researches on only longitudinal reinforcement corrosion [5,27,39] or only stirrups corrosion [7,20,26], theoretical analysis [29], evaluation and strengthening measures of seismic behavior for corroded RC columns [33]. However, there are few experimental studies on the effects of stirrup corrosion and longitudinal bars corrosion on the seismic performance degradation of columns, respectively, especially for the severely corrosion stirrups exceed of 20%, and the influence of corrosion degree on the failure mode of columns still needs to be further explored.…”

A Two-Year Evaluation of Corrosion-Induced Damage to Hot Galvanized Reinforcing Steel B500SP in Chloride Contaminated Concrete

“…Regarding durability in the corrosion environment, reinforced concrete should be identified with a steel electrode (half-cell) immersed in the highly alkaline pore solution filling the porous structure of concrete [6,7]. A combination of two different construction materials, being advantageous from the mechanical point of view, can create serious difficulties and complications related to the evaluation of the structure safety with reference to its durability [8][9][10]. The main problem is the lack of direct access to steel reinforcement covered with concrete or failure to make observations without measuring equipment.…”

“…A combination of two different construction materials, being advantageous from the mechanical point of view, can create serious difficulties and complications related to the evaluation of the structure safety with reference to its durability [ 8 , 9 , 10 ]. The main problem is the lack of direct access to steel reinforcement covered with concrete or failure to make observations without measuring equipment.…”