Corrosion of Reinforced Concrete

Title :
Multi-functional organic corrosion inhibitor

Authors :
Charles K. Nmai

Abstract :

In this paper, the multi-functional benefits of the water-based organic corrosion inhibitor are presented and discussed, with regard to the corrosion protection of embedded steel and resistance to chemical attack; specifically, the resistance of concrete to sulfate attack and deterioration due to sulfuric acid exposure. The organic corrosion inhibitor consists of amines and fatty-acid esters and the mechanisms by which it functions are presented and substantiated. In addition to a 30% of calcium nitrite inhibitor, this amine-ester based organic corrosion inhibitor is a commonly used corrosion inhibitor in new construction. Time-to-corrosion evaluations in 0.50 and 0.40 water-cementitious materials ratio concretes of moderate and high quality show that the inhibitor was effective regardless of concrete quality, and significantly reduced chloride ingress. The permeability-reducing property of the amine-ester based organic corrosion inhibitor has also shown effectiveness in reducing deterioration due to the ingress of other aggressive species such as sulfate and sulfuric acid. For comparison purposes, the corrosion-inhibiting performance of the amine-ester based organic inhibitor is compared to that of calcium nitrite, while its effect in mitigating sulfate attack and reducing deterioration due to sulfuric acid exposure is compared to that of silica fume.

Keywords :
Corrosion, Corrosion inhibitor, Organic, Water-based

Source :
http://www.sciencedirect.com/science/article/pii/S0958946503000398