الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
An experimental program was conducted through three phases were briefly presented in the current thesis, in addition to a finite element analysis executed using computer modelling. This research aims to employ the new generations of fiber reinforced High Performance Concrete (HPC) in order to present a better performance of the composite bridge girders in terms of sustainability besides accelerations in construction. The first experimental phase investigated the bond behavior of straight and headed ribbed Glass Fiber Reinforced Polymer (GFRP) bars embedded in Engineered Cementitious Composite (ECC), Fiber Reinforced Concrete (FRC) and Ultra-High Performance Concrete (UHPC). This phase was performed on forty-eight specimens using conventional pullout tests to evaluate the effects of embedment length, location of the GFRP bar (concentric and eccentric) and the type of used concrete on the bond strength, pullout load and failure modes. Results showed that the presence of compressive strength (fc`) appeared with significant effect on the mode of pullout failure, since the pullout observed by samples with lower fc` was accompanied with shearing-off and crushing of the concrete between the GFRP bar ribs as it was obtained by both ECC and FRC; however, fracture between the ribs and fibers in the rebar occurred when using concrete with higher compressive strength at it was observed by UHPC. The second phase investigated the behavior of composite bridge girders made of fiber reinforced HPC slab connected to steel I-beam through stud shear connectors subjected to hogging moment. This phase proposes the use HPCs containing fibers (with better crack resisting and strain hardening characteristics) in the deck slab to enhance both cracking and yield load carrying capacity of composite girders at the negative moment region. Four composite girder specimens made of different types of concrete and having variable slab continuity were tested to failure under monotonic loading simulating negative moment region. Three types of concrete were employed in the first three girder specimens, namely: Normal Concrete (NC), FRC and ECC, while the fourth girder was constructed using two FRC end slabs connected together with a UHPC closure strip located at the maximum negative moment mid span region. The FRC and ECC composite girders showed better performance in terms of cracking characteristics (multi-cracking and smaller crack width), higher pre-cracking linear stiffness, higher cracking load, higher concrete strain development during cracking and higher strength compared to their NC counterparts. The last experimental phase was to study the behavior of steel concrete composite girders subjected to repeated hogging moment. Constant Amplitude Fatigue (CAF) loading with elastic range followed by static hogging moment up to failure was applied on four composite bridge girders identical to those tested in the second phase. Results confirmed improvement in structural performance of such girders in terms of stiffness reduction, moment resistance, crack distribution and crack width control. AASHTO LRFD based specification was found to be safe in predicting moment capacity of composite girders incorporating mentioned HPCs.
Finally, the four composite girders with HPC deck slab tested statically up to collapse, as presented in Chapter 3, were nonlinearity examined using finite element analysis with explicit solver. Then, the good agreement of the results obtained numerically and experimentally for the fourth composite girder was extended to a parametric study executed on sixteen finite element model of real composite bridge girder provided by MTO with variables were: shear-key width and type of reinforcement bars (steel and GFRP). The presence of HPC deck slab can significantly contribute to both cracking and yield moment; however, this enhancement seemed to be insignificant for the ultimate composite action capacity