Influence of phosphate on chloride-induced corrosion of reinforcing steel in mortars

Author(s): Jinjie Shi, Wei Sun
Paper category: Conference
Book title: 2nd International conference on Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. Van Breugel, Wei Sun, Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Pages: 1353- 1362
Total Pages: 9
Language: English

Abstract: 
The influence of phosphate as a corrosion inhibitor on the corrosion behavior of asreceived and pre-rusted reinforcing steel in mortar specimens was investigated after exposure to 3.5% NaCl solution for 360 days, using electrochemical techniques for the reactions on the steel surface and microstructural observations of steel-mortar interface. The electrochemical methods, namely corrosion potential (Ecorr), linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) were employed to evaluate the corrosion tendency and general corrosion rate of steel. The results indicate that, unlike to nitrite, which is generally accepted as the anodic inhibitor, phosphate may be a cathodic inhibitor due to the reduced corrosion rate and more negative Ecorr if the concentration is the same for both inhibitors in mortar specimens. It has also been found that the inhibiting efficiency of general corrosion for phosphate is lower than 10% both for as-received and pre-rusted reinforcing steels, which is not as good as nitrite.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00