الفهرس 
The Research ObjectiveOnly 14 pages are availabe for public view
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Abstract
Bridges are type of structures constructed for the purpose of providing passage
over the obstacles (such as water, valley, road, or rail) without blocking the way
underneath. Box girders, have gained wide acceptance in bridge systems due to their
structural efficiency, better stability and serviceability, they can be constructed as single cell, double cell or multi cell. The rehabilitation of existing reinforced concrete (RC) bridges and building becomes necessary due to ageing, corrosion of steel reinforcement, defects in construction/design, demand in the increased service loads, and damage in case of seismic events and improvement in the design guidelines. Using FRP composites has become a popular structural strengthening technique, due to the well-known advantages of FRP composites such as their high strength-to weight ratio and excellent corrosion resistance. Also, using ferrocement as a rehabilitation material is a great choice because of its enhanced crack resistance, the high toughness and low cost of construction. This investigation studied experimentally and numerically the structural performance of reinforced concrete box girders strengthened with composite material as ferrocement, glass fiber-reinforced polymer (GFRP) and carbon fiber-reinforced polymer (CFRP) composites. The research included an experimental program to design and construction of fifteen box girders one of them is the control beam and the other box
girders strengthened with various types of composite material. All box girders are with dimensions 25x20x200 cm. The main objective of this research is to invistigate the effective of strengthening materials on the behavior of box girders in terms of ultimate load, first crack load, serviceability load, ductility ratio and energy absorption. The finite
element ANSYS program version 13.0 was used to simulate the tested box girders
numerically. The experimental and numerical results were compared and they were convergent. The specimens strengthened with CFRP give a higher structural performance than the specimens with GFRP and ferrocement. The strengthening materials had a noticed
effect on increase the first crack load, the ultimate load and the deflection corresponding to applied load compared to the control beam and the girder strengthened by 4 GFRP layers and the girder strengthened by 1 CFRP layer at the bottom flange and wrapping around the webs of the beam have the highest service load and ultimate load. Also, comparing the numerical results with the experimental results showed that the finite element model of the box girders gave a good agreement with the experimental results.