Kinetic Study of the Effect of C ₆ H ₅ ‐COONa as Corrosion Inhibitor on Concrete Properties

ABSTRACT This study tends to examine the use of sodium benzoate “C 6 H 5 ‐COONa” as a corrosion inhibitor added to the mixing water of concrete contaminated by chlorides, and test the mechanical performances of five types of concrete samples over several time periods, 7, 28, 56, and 90 days, in the absence and in the presence of limestone fillers and superplasticizing. Hence, the results confirm that the addition of “C 6 H 5 ‐COONa” increases the compressive resistance by 11.75%, 0.42%, 14.66%, and 20.63% comparing with the reference sample for the cited time periods, respectively. Also, the integration of limestone and superplasticizing significantly improves this resistance by 31.64%, 12.06%, 22.92%, and 21.88% respectively for 7, 28, 56, and 90 days. Tests were carried out on cement paste after the addition of sodium benzoate, results show that the start and the end setting time of cement shift out by 15.15% and 9.67% compared with reference cement. More than, after the addition of sodium benzoate and limestone fillers, the results indicate an increase in these parameters by 8.25% and 6.39% compared with reference cement, which indicates that sodium benzoate delays the start and end setting time of cement. In addition, Abrams cone slump tests were performed on fresh concrete for the different compositions in the absence and presence of superplasticizing “ORAFLOW THM 17200”. These results confirm that the addition of sodium benzoate to concrete does not negatively affect its properties in fresh or hard state, and then it can be used as a corrosion inhibitor for its reinforcements.