Preparation and Electrochemical Characterization of Microcapsules Containing Calcium Nitrate in Self-Healing Concrete

EasyChair Preprint no. 770, version 2

Abstract

We present the preparation and inhibition behavior of rebar in the presence of microencapsulated calcium nitrate (CN) with concentrations of 0.5, 2.0, and 5 wt.% in concrete. From both open circuit potential (OCP) and electrochemical impedance spectroscopy spectra, it was found that an addition of CN corrosion inhibitor-containing microcapsules into concrete beams successfully repassivated or maintained the passivity of the rebar when the concrete was cracked. This corrosion inhibitor healed the rebar by forming a passive layer on the rebar surface under the crack. This healing process was evident by an increase of OCP values to more positive values or by stable OCP values at around -100 mV vs SCE. An increase in phase angle after corrosion activation for CN C 2% clearly showed this healing process. The optimum concentration for maintaining the passivity on rebar in the cracked concrete was found to be 5 wt.%.

Keyphrases: calcium nitrate, Concrete, Corrosion inhibition, EIS, microcapsules

@Booklet{EasyChair:770,
  author = {Changkyu Kim and Reece Goldsberry and Ahmad Ivan Karayan and Jose Milla and Marwa Hassan and Homero Castaneda},
  title = {Preparation and Electrochemical Characterization of Microcapsules Containing Calcium Nitrate in Self-Healing Concrete},
  howpublished = {EasyChair Preprint no. 770},
  doi = {10.29007/4cn3},
  year = {EasyChair, 2019}}