الفهرس 
2. LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
The research is aimed to investigate the reinforcing steel corrosion in
different aggressive media. The study demanded two fields to be taken in
consideration:
from engineering perspective, which its focus lies on the effect of
variability of composition of silica fume, superplasticizer, and watercement
ratio on the physical-mechanical properties of concrete
(compressive strength, tensile strength, workability, slump and
permeability test).
Results showed that adding of 10% silica fume and 1%
superplasticizer (both by weight of cement) to concrete with w/c ratio 0.4
gives the highest value of resistance of compressive strength, tensile
strength, workability and permeability and small corrosion rate. For ratios
more than 10% of silica fume, the concrete durability decreases.
Furthermore, the influences of mix design and the type of binder are
evaluated and related to porosity.
from electrochemical perspective, which aimed to study the
electrochemical behavior of reinforcing steel in different media with the
presence of Cl- ions, SO4
-- ions and (SO4
--+Cl-) ions using linear
polarization , cyclic voltametric and open circuit methods.
Several results were concluded by the preceded electrochemical
experimental work. They could be briefed as:
- In all cases the steady state potential (Ess)was reached after 60 min.
from the start time of immersion
150
- Both Cyclic Voltammetry and Linear Polarization had nearly similar
results to determine the corrosion rate. In current study, Linear
Polarization technique was utilized because it gives results faster
than the other method.
- Corrosion rate decreases by increasing the compressive strength of
the sample
- The optimum admixture is the sample with w/c ratio 0.4 containing
silica fume with 10% and super plasticizer with 1% which gives high
corrosion resistance
- Also, the corrosion decrease as cover thickness of the sample
increase.
- The data obtained from linear polarization measurements are in good
agreement with that obtained from open-circuit potential.
The effect of Cl- ions in corrosion rate were examined using 5%
NaCl solution: the obtained results show that the corrosion rate is high
compared with that in tap water which can be attributed to the decrease of
C3A tricalcium aluminate which decrease Cl- ions concentration.
The effect of sulphate ions using 5% Na2SO4 solution was
investigated and the data reveal that SRC has highest efficiency to resist
corrosion of steel, the corrosion rate in sulphate medium is higher than tap
water and less than NaCl solution.
Time factor had also been monitored. A