الفهرس 
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Abstract
The corrosion of the reinforcement in concrete is a significant problem for concrete infrastructures which leads to forming expansion, loss of bond between rebars and concrete, loss of effective area of rebar, cracking, and eventual spalling of the concrete cover. Finally, the corrosion may cause structural damage to concrete structures. The corrosion inhibitor admixture is one of the different techniques used to protect the steel reinforcement.
In this research, the effect of adding different corrosion inhibitor admixtures on the properties of fresh and hardened concrete was investigated experimentally. Also, the effect of corrosion inhibitor admixtures on corrosion resistance and on the durability of concrete was investigated experimentally. Three different inhibitors were added individually in a concrete mix by a certain dosage. The inhibitors were amino and ester-based inhibitor, nitrite-based inhibitor, and phosphate-based inhibitor. Workability, compressive strength, splitting tensile strength, bond strength, and microstructure of concrete were evaluated. Also, corrosion resistance and other durability properties such as sorptivity, density, percent of absorption, and percent of permeable voids in hardened concrete were measured.An experimental program has been executed in this study. The experimental program is divided into two parts. The first part is designed to study the impact of using amino and ester-based inhibitor, nitrite-based inhibitor, and phosphate-based inhibitors on concrete mechanical properties. The influence of these inhibitors on workability, compressive strength, splitting tensile strength, bond strength were evaluated. Also, the microstructure of concrete was evaluated for each inhibitor using a scanning electron microscope.
The second part is aimed to study the concrete durability for each inhibitor in addition to high strength concrete (HSC). First; corrosion resistance was examined for each inhibitor. For corrosion acceleration purpose, the accelerated corrosion technique which is the galvanostatic method was used. The specimens used for corrosion measurement purpose were added in water containing 3% NaCl. Second; sorptivity, density, percent of absorption, and percent of permeable voids in hardened concrete were measured. Also, an economical study was made to compare the cost of one cubic meter for each of the five mixes. The increase in the cost of each mix from the control/blank mix was also calculated.
The obtained results are compared with findings reported in the literature. The findings of this research recommend the best of the tested inhibitors depending on the one that has the best or least negative effect on concrete properties. This one is the nitrite-based inhibitor, which exhibited good compressive strength. Also, the one that has the best effect on corrosion resistance is the nitrite-based inhibitor, which exhibited high efficiency in the acidic medium. While, high strength concrete exhibited the best results in sorptivity, density, percent of absorption, and percent of permeable voids tests.