Investigation for the Possibility of Improving the Reinforced Concrete Corrosion Resistance Using Polyaniline Coated Steel

摘要

This work investigates the possibility of improving the corrosion resistance of reinforced concreteagainst corrosive mediums mainly represented by chloride and sulfate ions by using polyaniline(PANi) coating. The polyaniline layer was formed using the galvanostatic technique and investigatedfor its composition by using X-Ray Photoelectron Spectroscopy (XPS). The potentiodynamictechnique was used for investigating the corrosion resistance of the PANi coated steel while coupledwith stainless steel and used for reinforcing a layer of concrete, containing different concentrations ofcorrosive materials such as NaCl and H2SO4 the corrosion current was measured against Ag/AgCl- - reference electrode. The main variables investigated were the initial concentration of both Cl and SO4 2 and the time interval from 0 to 28 days (initial hardening period). The results showed that using- polyaniline coating has improved the corrosion resistance of reinforced concrete against Cl by a factor-2 ranging from1.10 to 1.90 and by a factor ranging from 1.30 to 1.60% against SO4 of its value- -2 compared to uncoated steel depending on initial concentration of Cl and SO4 respectively. In- -2addition the results showed that Cl is superior to SO4 in causing corrosion of steel. The corrosion rate- -2of steel subjected to Cl ions is higher than that of SO4 by a factor of 1.688 and 1.815 for both bareand polyaniline coated steel respectively.