Diffusion analysis of chloride in concrete following electrokinetic nanoparticle treatment

K. Kupwade-Patil, T. J. John, B. Mathew, H. Cardenas, H. Hegab

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Concrete is a highly porous material which is susceptible to the migration of highly deleterious species such as chlorides and sulfates. Various external sources including sea salt spray, direct sea water wetting, deicing salts and brine tanks harbor chlorides that can enter reinforced concrete. Chlorides diffuse into the capillary pores of concrete and come into contact with the rebar. When chloride concentration at the rebar exceeds a threshold level it breaks down the passive layer of oxide, leading to chloride induced corrosion. Application of electrokinetics using positively charged nanoparticles for corrosion protection in reinforced concrete structures is an emerging technology. This technique involves the principle of electrophoretic migration of nanoparticles to hinder chloride diffusion in the concrete. The re-entry of the chlorides is inhibited by the electrodeposited assembly of the nanoparticles at the rebar interface. In this work electrochemical impedance spectroscopy (EIS) combined with equivalent circuit analysis was used to predict chloride diffusion coefficients as influenced by nanoparticle treatments. Untreated controls exhibited a diffusion coefficient of 3.59 × 10 -12m2/s which is slightly higher than the corrosion initiation benchmark value of 1.63 × 10-12m2/s that is noted in the literature for mature concrete with a 0.5 water/cement mass ratio. The electrokinetic nanoparticle (EN) treated specimens exhibited a diffusion coefficient of 1.41 × 10-12 m2/s which was 25 times lower than the untreated controls. Following an exposure period of three years the mature EN treated specimens exhibited lower chloride content by a factor of 27. These findings indicate that the EN treatment can significantly lower diffusion coefficients thereby delaying the initiation of corrosion.

Original languageEnglish
Title of host publicationASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels Collocated with 3rd Joint US-European Fluids Engineering Summer Meeting, ICNMM2010
Pages305-312
Number of pages8
EditionPARTS A AND B
DOIs
Publication statusPublished - 2010
Externally publishedYes
EventASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2010 Collocated with 3rd Joint US-European Fluids Engineering Summer Meeting - Montreal, QC, Canada
Duration: Aug 1 2010Aug 5 2010

Publication series

NameASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels Collocated with 3rd Joint US-European Fluids Engineering Summer Meeting, ICNMM2010
NumberPARTS A AND B

Conference

ConferenceASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2010 Collocated with 3rd Joint US-European Fluids Engineering Summer Meeting
Country/TerritoryCanada
CityMontreal, QC
Period8/1/108/5/10

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

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