WTI

Electrochemical Rehabilitation of Salt-Contaminated Concrete: A Lab Study - UTC

Primary Investigator Contact Information

External Project Contact(s)

Report(s)

1. Assesment of Electrical Injection of Corrosion Inhibitor for Corrosion Protection of Reinforced Concrete
   1. Tongyan Pan, Tuan Anh Nguyen, Xianming Shi
   2. 4W1411_TRB08.pdf

Project Objective

To establish preliminary investigation of key factors affecting the performance of electrochemical chloride extraction (ECE) and electrical injection of corrosion inhibitors (EICI), and to validate a modeling framework that may guide the blueprint of ECE/EICI.

Project Abstract

Chloride-induced corrosion of reinforcing steel is the major cause for premature failure of reinforced concrete structures exposed to salt-laden environments. The traditional repair method of corrosion-damaged reinforced concrete consists of replacement of the corrosion damage with chloride-free concrete. However, this technique is not a durable solution, as the chloride-containing materials have not been removed from the structure. Both cathodic protection (CP) and electrochemical chloride extraction (ECE) techniques are proven to extend the service life of a treated structure; however, ECE offers some advantages over the use of CP such as the elimination of continuous power supply and regular maintenance by driving away chloride ions from the negatively charged reinforcing steel and potentially out of the concrete. In addition, electrical injection of corrosion inhibitors (EICI) into concrete is a relatively new technique with promising results. There has been limited research and field trials of ECE and EICI and widespread applications are hampered by the lack of detailed information on the underlying mechanisms and relevant rate-limiting steps. WTI researchers will investigate and validate a modeling framework for the promising techniques of ECE and EICI to treat chloride contamination in concrete.

Task Descriptions

1. Laboratory Investigation
   1. After the electrochemical treatment of salt-contaminated concretes, a combination of chemical titration methods, FSEM/EDS and UV-Vis will be used as necessary to analyze the chloride and inhibitor concentration along the depth of concrete for each sample. The results of these experiments will be incorporated into a modeling framework established at the WTI Corrosion & Electrochemistry Laboratory and used to refine/calibrate underlying assumptions.
2. Literature Review
   1. Research of existing projects related to ECE and EICI.
3. Final Paper
   1. The final paper will document the background information, methodology and research findings.
4. Experimental Design
   1. Researchers will design experiments that test the electrically-assisted transport of chloride and a corrosion inhibitor selected via electrochemical corrosion and electromigration testing (e.g., quaternary ammonium salts) in Portland cement concretes.

Milestones, Dates, Schedule

Student Involvement

False

Relationship to Other Research Projects

True

Technology Transfer Activities

False

TRB Keywords

Concrete durability, electrochemical rehabilitation, corrosion inhibitor

Partners

Research and Innovative Technology Administration