The Effect of a Corrosion Inhibitor on the Rehabilitation of Reinforced Concrete Containing Sea Sand and Seawater

Abstract

Concrete made with sea sand and seawater is rich in chlorine ions which are the main factors that induce corrosion of the reinforcement. In this study, an innovative method to rehabilitate reinforcement is presented; the concentrations of chloride ions and the corrosion inhibitor in concrete were measured. Electrochemical chloride extraction (ECE) was applied as a control experiment via using saturated Ca(OH)2 solution as an external electrolyte. Bidirectional electromigration (BIEM)technology combined with the corrosion inhibitor could not only remove the chloride ions but also protect the steel bar in concrete, and animidazoline inhibitor mixed in concrete is more effective than thetriethylenetetramine inhibitor due to the specific molecular structure. It was found that the optimum ratio of N/Cl reached the maximum value 3.3, when the concentration of inhibitor was 1. Meanwhile, the experimental results also revealed that the corrosion inhibitor and chloride ion concentrations reached necessary levels on the surface of the steel, and the corrosion inhibitor migrated effectively. Overall, the contents of imidazoline and triethylenetetramine inhibitor in seawater concrete are0.75% and 1%, respectively. The results demonstrate that the addition of the corrosion inhibitor and the application of bidirectional electromigration would effectively improve the durability of reinforced concrete containing sea sand and seawater.

A review of recent advances in the science and technology of seawater-mixed concrete

“…Various strategies have been proposed for overcoming the problem of steel reinforcement corrosion in seawater-mixed concrete. For example, the use of cathodic prevention [81], as well as the use of corrosion inhibitors [82][83][84] were explored to enhance the durability of seawater concrete. Epoxy coated rebars have been also proposed in combination with seawater-mixed concrete [76], however the presence of defects or scratches might drastically impair their reliability.…”

Bestmittel and Silica Fume Effect on Concrete Compressive Strength With Seawater Curing

“…The ensuing electrolytic process involving these ions harms the adjacent concrete structure (Fahirah, 2007). The primary factor contributing to reinforcement corrosion is the presence of the chloride ions in seawater (Pan et al, 2020;Wang et al, 2019). According to a previous study (Yu et al, 2018), the elevated presence of chloride ions in saltwater increases the susceptibility of steel reinforcement instructions to corrosion over a prolonged period.…”

Effect of Electrochemical Corrosion on the Properties of Modified Concrete

“…These electrochemical reactions are most often caused by the flow of electric current through the steel-concrete interface, during which electrochemical corrosion influences both the mineral matrix and the reinforcement [3,5,[32][33][34].…”

“…Thus, moisture, impurities, and air permeability can accelerate the process of electrochemical corrosion. The use of a fine aggregate containing impurities such as salts can negatively affect the hydrogen index, leading to deterioration of the protective oxide film on the surface of the metal [2,4,11,14,33,34].…”