Abstract

The corrosion of steel reinforcement has been a prime concern for concrete users. Chloride ingress into the concrete matrix disturbs the passive layers in the vicinity of steel, which results in corrosion initiation. Cementitious materials were successfully implemented in concrete mixtures to enhance their properties and minimize chloride permeability into concrete. Although numerous tests and techniques have been developed over the past years, reliable assessment of chlorides remains a challenging task. Th.is study aims at enhancing the understanding of techniques used for the assessment of chloride ingress and investigating potential correlation between these techniques. The study comprised eighteen mixtures made with various water-to-cementitious materials ratios, with and without organic and inorganic corrosion inhibitors. Mixtures incorporated ordinary cement, high-slag cement and silica fume. Together with conventional fresh and hardened concrete testing, the assessment techniques included rapid chloride permeability test, ponding test, permeability index and macrocell potential technique. Steel bars were removed from concrete after exposure to chlorides and were visually inspected. A computer model, which was developed at the University of Toronto by Thomas and Bentz, was also utilized to predict the duration for corrosion initiation associated with the various mixtures in order to compare the output with the experimental results. The study highlights the discrepancy between various test results and the level of reliability associated with each assessment technique. It also pinpoints potential correlation between these techniques. The study reveals that the cementitious materials play a more pronounced rule in miniizing corrosion risk when compared with the corrosion inhibitors. The organic inhibitor herein exhibited better performance than the inorganic inhibitor. The study shows that combining specific assessment techniques strengthens the reliability of results and enhances the assessment of chloride ingress and hence the assessment of corrosion risk.

School

School of Sciences and Engineering

Department

Interdisciplinary Engineering Program

Date of Award

2-1-2003

Online Submission Date

1-1-2002

First Advisor

Mohamed Nagib Abou-Zeid

Committee Member 1

Mounir Mohamed Kamal

Committee Member 2

Safwan Khedr

Committee Member 3

Ezzat Fahmy

Document Type

Thesis

Extent

242 leaves

Library of Congress Subject Heading 1

Concrete

Library of Congress Subject Heading 2

Concrete

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

Call Number

Thesis 2002/77

Location

mmbk

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Included in

Engineering Commons

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