In this study, an epoxy/polyaniline–camphorsulfonate nanocomposite (epoxy/PANI–CSA) is employed to
protect reinforcing steels in chloride-laden concrete environment. The synthesized nanocomposite was
characterized using Fourier transform infrared spectroscopy and transmission electron microscopy. Bare,
epoxy-coated and epoxy/PANI–CSA nanocomposite-coated steel rebars were embedded in normal and
self-compacting concretes. To evaluate their corrosion behaviors, open circuit potential and impedance
measurements were performed for the duration of 1 year. Ultimate bond strength of concrete with the
reinforcement bars were measured in corroded and uncorroded conditions. It was found that epoxy/
PANI–CSA coating provides good corrosion resistance and durable bond strength with concrete for steel
rebars.
In this study, the use of epoxy/polyaniline–camphorsulfonate
(epoxy/PANI–CSA) nanocomposite is introduced as a new method
to protect steel rebars embedded in concrete. It should be noted
that there is no report available on the use of this type of self-healing
coatings for protection of steel reinforcements. Generally, the
coating preparation procedure contains two separate parts; synthesizing
of PANI and incorporating of the synthesized PANI into
epoxy resin [24,25]. In this way, the major problem is the agglomeration of PANI pigments while adding them into epoxy
matrix so that a rigorous sonication is generally needed to prevent
this phenomenon. In our previous work, this problem was eliminated
by introducing a novel one-pot procedure in which the synthesizing
process of PANI is performed in epoxy media and the
epoxy/PANI–CSA nanocomposite is prepared without any further
treatment [23]. Present work concerns with the application of
the introduced one-pot procedure in order to synthesize the
epoxy/PANI–CSA nanocomposite for corrosion protection of steel
rebars. Afterward, the synthesized epoxy/PANI–CSA nanocomposite
is characterized using Fourier transform infrared spectroscopy
(FTIR) and transmission electron microscopy (TEM) techniques.
The chloride-induced corrosion of bare, epoxy-coated and epoxy/
PANI–CSA nanocomposite-coated steel rebars embedded in normal
(NC) and self-compacting concrete (SCC) are investigated using
open circuit potential and impedance measurements. Ultimate
bond strength of concretes with the reinforcement bars are
measured in corroded and uncorroded conditions. In addition,
the chloride permeability of concretes is evaluated.