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Strength and ductility performance of corroded steel bars in concrete exposed to 2D chloride ingress

Published online by Cambridge University Press:  11 August 2020

Mike Otieno Open the ORCID record for Mike Otieno [Opens in a new window]  and
Ze Zakka
Mike Otieno*
Affiliation:
School of Civil and Environmental Engineering, University of the Witwatersrand, Johannesburg
Ze Zakka
Affiliation:
School of Civil and Environmental Engineering, University of the Witwatersrand, Johannesburg
*
Corresponding author: Mike Otieno (Mike.Otieno@wits.ac.za)
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Abstract

This paper presents the residual tensile strength test results of corroded high yield steel bars. Single steel bars were embedded at a cover depth of 20 mm in 150 × 150 × 625 mm long cracked concrete beam specimens made with 70/30 PC/FA and 50/50 PC/SL binders with a constant w/b ratio of 0.40. The steel bars were placed in the cross-section centre and near the orthogonal edge of the beams, and selected beam faces epoxy-coated in order to simulate, respectively, 1D and 2D chloride ingress. The beams were subjected to 2-week wetting (with 5% NaCl) and 2-week air-drying cycles in the laboratory for 110 weeks after which the corroded steel bars were extracted, assessed for corrosion morphology, and tested in tension for ultimate strength, fracture strength and ductility performance. The steel bars in concretes exposed to 1D chloride ingress had isolated corrosion pits while both general and isolated corrosion pits were observed in specimens exposed to 2D chloride ingress. The residual ultimate and fracture tensile strengths, and ductility of corroded steel reinforcing bars in concretes exposed to 2D chloride ingress are lower than those for steel bars in concretes exposed to 1D chloride ingress.

Type
Articles
Information
MRS Advances , Volume 5 , Issue 54-55: Nanoscale and Quantum Materials , 2020 , pp. 2817 - 2825
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Copyright
Copyright © Materials Research Society 2020

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