الفهرس 
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Abstract
Corrosion problems occupy a large important forasmuch the damage
that it causes whether on the spirits or costs; therefore it is necessary trying
to find methods to limit corrosion process. Science is a multidisciplinary
area of research where nanotechnology potentially offers the opportunity to
enhance the understanding of concrete behavior, to engineer its properties
and to lower production and ecological cost of construction materials. Nano
science and technology is a new field of emergence in materials science
and engineering, which forms the basis for evolution of novel technological
materials. Nano technology finds application in various fields of science
and technology.
This research aims to study the effect of different concentration of
HCl on the corrosion rate and flexural capacity of RC structures. Also, the
effect of different accelerated corrosion periods on the corrosion rate and
flexural capacity of RC structures was considered.
In view of appearance Nano technology as solution to limit the
corrosion for steel bars in RC structures, Nanoparticles were used with
different types and concentrations to study its effect on the corrosion rate,
mechanical properties of concrete and flexural capacity for RC slabs.
In this research, An experimental program of three different groups
were carried out, these three groups are steel bars, reinforced concrete
cylinders and reinforced concrete slabs. Twenty-four steel bars treated by
different treatment methods of nano-CaCo3 particles were exposed to
different HCl concentrations (0, 1, 2, 3, 4 and 5%). 144 RC cylinders with
different nanoparticles CaCo3, SiO2, Al2O3 and MgO with different
concentrations (0, 0.5, 1, 2, 3and 5%) to each nano type were exposed to
different concentrations (0, 0.5, 1, 2, 3and 5%). Thirty-one reinforced
concrete slabs treated by nano- CaCo3 particles were exposed to different
HCl concentrations (0, 2, and 5%) and accelerated corrosion setup periods.
The electrochemical behaviors of reinforcing steel were determined
by linear polarization techniques for the three groups by using voltalab 10
PGZ100 ”all- in –one” Potentiostate / Galvanostate system in order to
measure corrosion rate for every group. Compressive strength of groups
two and three was recorded in order to know the effect of HCl media and
nano treatment on strength of concrete. Frame loading test was performed
on group three to know the flexural capacity of slabs and corresponding
deflection under the effect of different HCl, nanoparticles concentration
and variable accelerated corrosion setup periods.
Electrochemical results for steel bars group indicated that the
increase in HCl concentration causes increase in corrosion rate. By
introducing nano treatment, it was found that corrosion rate of steel bars
decreased.
Compressive strength and electrochemical results for group two show an
improvement of mechanical properties of concrete and high ability to resist
aggressive attack especially in presence of alumina dioxide and silica
dioxide nanoparticles, this result reflects on the corrosion behavior of
reinforcing steel in concrete containing these nanoparticles. Both alumina
dioxide and silica dioxide reduce the chance of reinforcing steel to
corrosion to region of passivation. Calcium carbonate gets the same
behavior of alumina and silica dioxide but with less efficiency and with
another mechanism. The impacts of nano- magnesium oxide particles are
negative especially with high concentration.
from results of electrochemical test, it was found that HCl contained
in slabs increase corrosion rate, while utilization of nano treatment
decreases the corrosion rate.
The compressive strength and the flexural test results illustrate that
concrete strength increases in the presence of HCl media or nano treatment.
It was recorded reduction in ultimate load capacity with the increase in the
accelerated corrosion setup period.
This research illustrated the importance of nanoparticles in limiting
reinforcement corrosion in concrete and increasing concrete strength.