Title:
Corrosion Mitigation in Reinforced Concrete Beams via Nanoparticle Treatment
Author(s):
Kunal Kupwade-Patil, Henry E. Cardenas, Kanielle Gordon, and Luke S. Lee
Publication:
Materials Journal
Volume:
109
Issue:
6
Appears on pages(s):
617-626
Keywords:
corrosion; electrochemical chloride extraction; electrokinetic; nanoparticle; porosity.
DOI:
10.14359/51684159
Date:
11/1/2012
Abstract:
Reinforcement corrosion in concrete is a major cause of damage in the civil infrastructure. This study evaluates the corrosion behavior of reinforced concrete beams when subjected to electrokinetic nanoparticle (EN) treatment. The EN treatment used an electric field to transport 24 nm nanoparticles directly to the steel reinforcement via capillary pores. Each beam was subjected to saltwater exposure followed by electrochemical chloride extraction (ECE) in concurrence with EN treatment. The specimens were re-exposed to saltwater following treatment. The results from this test indicate significantly lower corrosion current density among the EN-treated specimens (0.014 mA/cm2 [0.09 mA/in.2]) compared to the untreated control specimens (2.12 mA/cm2 [13.67 mA/in.2]). Mercury intrusion porosimetry (MIP) was used to examine the microstructural impact of the treatment process. A reduction in the porosity (adjacent to the steel) of as much as 74% was observed due to EN treatment. During treatment application, the electric field also caused chlorides to be drawn away from the reinforcement and extracted from the concrete beam. After the chloride was extracted, the nanoparticles appeared to form a physical barrier against chloride repenetration.