الفهرس 
CHAPTER 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
Text in English, Abstracts in English and Arabic.
The majority of recent RC buildings today are extremely safe. Nevertheless, it is impossible to make the identical claim for constructions established in the past. Furthermore, several of such buildings were built absent standards or depended on ones that proved insufficient. Furthermore, numerous ancient constructions appear to have reached the end of their useful capacity and, in a number of instances, were constructed to withstand loads less than what is required nowadays. As a result, structural assessment along with strengthening are deemed essential in order for them to satisfy comparable standards as buildings constructed nowadays.
RC frame connection is a crucial location due to the combined influence of cracking and the highest shear-bending stress, resulting in collapse. Therefore, the purpose of the research was to look into the efficiency of strengthening strategies to enhance the connection and delay or avoid breakdown.
FEA has been used to analyze the influence of different factors on connection response, such as the amount of GFRP-CFRP layers, the variable steel plate thickness, ferro-cement with various radiuses of expanded wire mesh, the position of steel plate stiffeners and RC blocks, the concrete’s compressive strength, and the volume of steel rebar. FEA can supplement existing testing and be used for parametric studies because it can demonstrate various aspects of collapse.
Before developing a numerical model of an RC frame connection, some existing literature in the relevant field that concentrates on experiments and numerical models is thoroughly reviewed.
Material nonlinearity is modeled for nonlinear finite element analysis by accounting for the nonlinear impacts of cracking and crushing of concrete as well as steel reinforcement yielding. A whole simulation demands concrete’s elastic characteristics and inelastic stress-strain relationships. The concrete damage plasticity model is employed to simulate the concrete material’s behavior. Additionally, reinforcing steel is an elastic, completely plastic material.
The analysis’s results indicate that strengthened materials raise load-carrying capacity to varying degrees. Through confinement, it also delays crack initiation at the connection. According to the findings, using one layer of CFRP presents more connection resistance compared to GFRP. Moreover, in this case, the optimized steel plate thickness is 6 mm, which also reduces deflection. If higher levels of ductility are needed, a strength-ductility trade-off is possible. Furthermore, utilizing expanded wire mesh with a thickness of 1 mm to reinforce ferro-cement enhances strength by 41%. Although ferro-cement is low-cost, the research recommends using it with expanded wire mesh to improve capacity. Also, stiffeners used in the tension region increase resistance by 33%, while stiffeners used in both the tension and compression regions increase strength by 48.7%. On the other hand, employing RC blocks improves resistance by 74%. Also, utilizing RC blocks in tension and compression zones increases connection capacity as well as reversal moment resistance.