Doctoral Dissertations

Keywords and Phrases

anti-corrosion; coating; double protection; magnesium potassium phosphate cement; mild steel bars

Abstract

"In this research study, the anti-corrosion mechanism of reinforcement embedded in magnesium potassium phosphate cement (MKPC) is explored. In addition, one type of additives, metakaolin, and one type of retarder, boric acid, are employed in MKPC to modify its properties in order to further investigate corrosion resistance and to achieve mass-production coating reinforcement at the work site. This coating method may be practical for some underwater construction and some traditional reinforcement concrete structures to reduce the reinforcement corrosion rate and to eventually extend service life in both repair and new construction applications.

By comparing the electrochemical properties of bare ribbed mild steel bars (commonly referred to as black steel) and bars coated with ordinary Portland cement (OPC) paste and MKPC paste through an electrochemical test, the testing results indicate that MKPC paste has far better anti-corrosion ability than OPC paste coating. The merit of MKPC paste coating is attributed to a double-protection mechanism–the dense microstructure of MKPC coating part and the formation of an iron (III) phosphate passivation layer between the substrate steel and the MKPC paste coating.

The studies presented in this work show that the MKPC coating system is technically feasible in delaying the level of corrosion for mild steel bars in a 3.5 wt.% NaCl corrosion solution. The MKPC coating system have promising marketability for new construction and hold promise for repair applications. Additional work on the mixing ratio can be undertaken to further modify and optimize"--Abstract, p. iv

Advisor(s)

Mers, John

Committee Member(s)

Ma, Hongyan
Yan, Guirong "Grace"
Sneed, Lesley H.
Chandrashekhara, K.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2022

Pagination

xvii, 185 pages

Note about bibliography

Includes_bibliographical_references_(pages 179-184)

Rights

© 2022 Fan Zhang, All Rights Reserved

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12283

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