الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Repair and rehabilitation of existing structures is becoming a major part of the present construction activities. Corrosion of reinforcement is a major contributing factor to the deterioration of reinforced concrete steel structure. Corrosion of reinforcing steel severely influences the bond at the steel-concrete interface. This investigation aims to study the effect of using different concrete compositions, corrosion levels and epoxy coating on the corrosion and the bond strength behavior. An accelerating corrosion cell was used to produce corroded steel bars with different corrosion levels. In this study, corrosion levels ranged from 0% to 30%. Four different concrete compositions were considered, including corrosion inhibitor, silica fume, latex and the control mix. Accelerating corrosion test and pullout test were used to study the corrosion and the bond strength. The used voltage in this test was 50 DC volts and the current intensity was recorded along the time. Compressive strength, splitting tensile strength, time at first crack, critical time, percentage of weight loss, corrosion rate and pullout bond strength were used to evaluate the effect of the studied parameters. from the test result it was clear that the use of 3.43% corrosion inhibitor and 10% silica fume improved the 28-day compressive strength and the 28-day splitting tensile strength. In addition, the use of 20% latex reduced the 28-day compressive strength while enhanced the 28-day splitting tensile strength. Also, the use of corrosion inhibitor enhanced the corrosion resistance of concrete and did not effect on the pullout bond strength for different corrosion levels. It was also observed that the use of 10% silica fume and 20% latex gave a positive effect on the corrosion resistance and enhanced the pullout bond strength for different corrosion levels. First and critical time at 20% corrosion level is lower than that at 0% corrosion level for different concrete compositions nearly by 50.0%. However, corrosion level more than 20% has insignificant effect on first and critical time compared with that of at 20% corrosion level. After critical crack, the corrosion level more than 20% had insignificant effect on pullout bond strength. Using 3.43% corrosion inhibitor and 10% silica fume with epoxy coating steel enhanced the efficiency of the epoxy coating in resisting steel corrosion. However, the epoxy coating reduced bond strength more than that of plain concrete.