The Effect of Addition Potassium Permanganate on Bond Strength of Hot-Dip Galvanized Plain Bars with Cement Paste

• Published in: Materials Vol. 16; no. 7; p. 2556
• Main Authors: Pokorný, Petr, Vacek, Vítězslav, Prodanovic, Nikola, Zabloudil, Adam, Hurtig, Karel
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23.03.2023; MDPI
• Subjects: Anions; bond strength test; Bonding strength; Cathodic corrosion; Cement; Cement paste; Coatings; Compressive strength; concrete; Concrete mixing; Construction industry; Corrosion; Corrosion and anti-corrosives; Epoxy resins; Evaluation; Galvanized steel; Galvanized steels; Hot dip galvanizing; hot-dip galvanized steel; Hydration; Hydrogen; Hydrogen evolution; Open circuit voltage; permanganate; Potassium permanganate; United Kingdom; Czech Republic; concrete; bond strength test; corrosion; hot-dip galvanized steel; permanganate
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16072556

In this paper, the effect of gradually increasing amounts of KMnO (10 , 10 , 10 mol·L ) in cement paste on the bond strength of a plain hot-dip galvanized steel bar was evaluated. The open-circuit potential of HDG samples in cement paste with various additions of MnO was monitored in order to follow a transfer of zinc from activity to passivity. Furthermore, the influence of the addition of these anions on the physicochemical properties of normal-strength concrete or cement paste was evaluated by means of hydration heat measurements, X-ray diffraction analysis, and compressive strength. The effective concentration of MnO anions prevents the corrosion of the coating with hydrogen evolution and ensures that the bond strength is not reduced by their action, which was determined to be 10 mol·L . Lower additions of MnO anions (10 mol·L ) are ineffective in this respect. On the other hand, higher additions of MnO anions (10 mol·L ), although they ensure the corrosion of the coating in fresh concrete without hydrogen evolution, but affect the hydration process of the cement paste that was demonstrated by slight water separation.