Uniform and Local Corrosion Characterization and Modeling Framework for Long-Term Exposure of Different Rebars Used for RC Elements in the Presence of Chloride Conditions
Document Type
Conference Proceeding
Publication Date
1-1-2022
Abstract
In this work we will present the corrosion behavior of ASTM 615 (steel rebar), ASTM 767 (Steel rebar with hot dip galvanized zinc layer) and ASTM 1094 (steel rebar with continuously galvanized zinc layer) rebars upon long-term exposure in simulated concrete pore solution (SCPS) with 3.5 wt.% NaCl. The rebars react in the SCPS to form corrosion products on the surface, the classic degradation mechanism accounts for the general corrosion dissolution. The corrosion behavior was monitored continuously by electrochemical methods such as open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) to account for mechanistic analysis and durability assessment. Upon long-term exposure with electrochemical methods, the surface rebar conditions were characterized assuming uniform corrosion. With the concentration of NaCl beyond the so-called threshold passive breakdown layer; the formation and propagation of local attack sites is feasible. Following different exposure times, the rebars were characterized by surface imaging. Surface analysis shown the local corrosion conditions (i.e. pits) due to the attack distribution and the metal loss depth. This chloride-induced corrosion process causes reduction of the cross-ional area of the reinforcing steel. Recently the assumption of the loss of capacity due to the homogeneous degradation has some pitfalls, the most important is the local attack in some sites of the metallic rebar. By considering the local degradation, a more holistic idea about the performance and integrity of the rebar as a system was obtained. From the experimental results we were able to propose a framework for the two different rebar materials used in the RC elements and the potential impact in the integrity of the RC systems.
Publication Source (Journal or Book title)
Lecture Notes in Civil Engineering
First Page
794
Last Page
804
Recommended Citation
Narayanan, D., Lu, Y., Okeil, A., & Castaneda, H. (2022). Uniform and Local Corrosion Characterization and Modeling Framework for Long-Term Exposure of Different Rebars Used for RC Elements in the Presence of Chloride Conditions. Lecture Notes in Civil Engineering, 200 LNCE, 794-804. https://doi.org/10.1007/978-3-030-91877-4_90