Application of Inhibitors to Reduce the Hydrogen Uptake of Steel During Electrochemical Chloride Extraction

Chloride attack is a major cause of deterioration of reinforced and prestressed concrete structures. Electrochemical chloride extraction is the removal of chlorides from the vicinity of reinforcement, leaving otherwise sound concrete intact. Atomic hydrogen is created at the surface of cathodically polarized reinforcement as a result of the critical threshold potential for hydrogen generation being exceeded during electrochemical chloride extraction. High-strength steels in prestressed concrete structures are susceptible to brittle fracture because of the absorption of hydrogen; therefore, the application of electrochemical chloride extraction on prestressed concrete structures has been questioned in the past. However, a review showed that some high-strength steels seem to be less affected by hydrogen embrittlement. In addition, inhibitors have been used previously with concrete structures to reduce corrosion risks. Inhibitors can also be used to mitigate hydrogen absorption. Based on a thorough review of the application of inhibitors and the hydrogen embrittlement phenomenon, this paper reports on the efficiency of inhibitors for the suppression of hydrogen uptake of steels in artificial concrete pore solution and evaluates the migration properties of inhibitors in concrete.