الفهرس 
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Abstract
Inverted-T bent caps have been widely used worldwide to reduce the overall elevation of bridges, improve the available clearance beneath beams, and improve aesthetics. The flange of the inverted-T serves as a shallow ledge to seat the bridge girders, while the web of the inverted-T, rising above the ledge, have the sufficient depth to deliver the required flexure, shear strength and stiffness. The loads from the girders are applied to the ledges at the bottom of the inverted-T section and transferred to the web through the stirrups that act as hangers. The bottom flange (ledge) must have sufficient transverse and punching shear capacity to enable the transfer of applied loads to the web. Diagonal cracks at the reentrant corners between the cantilever ledges and the web in older, existing inverted T- concrete bent beams have been reported.
This thesis presents an experimental program to introduce different strengthening schemes of the inverted T- concrete bent beams when the steel reinforcement of hangers and flexural reinforcement of the ledges are not sufficient. The test specimens consisted of eight simply supported beams with 3.0 meters span, a height of 500 mm, web width of 180 mm and ledge height of 160mm. Concrete jacket, steel jackets and external prestressing steel were used to strengthen the test specimens. The specimens were tested to failure, while the general deformational behavior was observed. The different strengthening schemes are evaluated in terms of behavior ductility and serviceability to identify the best scheme.
A finite element model was used to simulate the tested beams using “ABAQUS” program. Both the properties of steel reinforcement and concrete were simulated to represent the actual behavior of the tested beams. The finite element models’ results were verified against the experimental results and showed a good agreement with the tested beam results.
A parametric study was carried out to include variables which were not considered in the experimental program. Design recommendations and guidelines are reported to calculate the strength of inverted-T concrete bent caps.