الفهرس 
صفحة العنوانيوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
ABSTRACT
The FRP reinforcement of concrete columns is an important topic that has been the subject of numerous researches in the last 20 years. Both in the experimental and in the analytical and numerical terms, there is now a wide range of proposals and experimental results in the literature that analyze the benefits of FRP bandage. In details, many available studies deal with the compressive behavior and analyze the effects of confinement on the increasing in axial and deformational capacity. However, The almost the totality of the available models are not able to take into account the presence of an existing stress/strain state in a concrete column at the moment of application of the fiber laminates. In some of the existing models, although it could be possible to consider existing loads/strains on concrete prior confinement through an iterative procedure for dilating concrete. Levels of service loads applied on the RC column caused conservative for using confinement techniques especially when the service-applied loads exceed than a half of the ultimate capacity of RC columns. therefore, In this work, the special test set-up was used to simulate the existing RC columns under different levels of the service loads as in the construction field during confinement process. The experimental work studied the effect of existing service load during confinement by ratio 0.0%, 20.0%, 40.0%, and 60.0% of maximum capacity of the unconfined RC column during confinement processes on the behavior of strengthening RC columns by confinement. The experimental program consisted from thirteen tested RC columns divided to four groups. The type of confinement (full or partial) and type of section (square or circular) is studied parameters. The analysis of the tested results shown that the existing service load during strengthened RC columns by confinement is the major parameter affected on the behavior of strengthening RC columns. The load carrying capacity of the tested strengthening RC columns by confinement with CFRP-shell decreased 16% comparing with the unconfined RC column capacity and 10% comparing with confined RC columns capacity because of existing service load during confinement process. Moreover, the existing service load during confinement trend to decrease the ultimate axial strain, and significant increase the ultimate redial strain occurred.