الفهرس 
CHAPTER (1): INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Corrosion of steel reinforcement has become a major concern for reinforced concrete structures reducing the service life of the structures and increasing maintenance and repair costs. Fiber reinforced polymers (FRP) bars have gradually gained the acceptance as an attractive substitute for steel reinforcement in the last decades especially in regions where harsh environments prevail. However, studies concluded that FRP-RC members exhibited limited ductility under bending. To improve the ductility and meanwhile ensure satisfactory corrosion-resistant performance, a new type of FRP reinforced ultra high performance strain hardening cementitious composites (UHP-SHCC) encased steel composite beams (FRP-RUS) comprised of ductile mortar (UHP-SHCC) encased steel section in combination with corrosion-resistant FRP-bars was proposed and studied. An experimental investigation on flexural behavior of the proposed beams was conducted by testing a total of eight simply supported beam specimens subjected to four-point bending loads. The group of beams divided into four groups regarding to the type of encasing material either concrete or UHP-SHCC (group 1), type of reinforcement included (BFRP), (GFRP) and (CFRP) (group 2), existing of steel section (group 3) and percentage of UHP-SHCC layer of the beam’s depth (50% and 75%) (group 4). The test results indicate that using UHP-SHCC as an encasing material can provide an enhancement in load carrying capacity, ductility and energy dissipation capacity of tested beams. The normal strength concrete (NSC) encased specimen showed a brittle behavior during failure and this behavior disappeared by replacing normal concrete with UHP-SHCC as an encasing material. In addition, the suggested numerical models using nonlinear finite element analysis by ABAQUS program were able to simulate the flexural behavior and predicted the load carrying capacity of the proposed FRP-RUS beams.