الفهرس 
1.5 OBJECTIVES
LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
Use of carbon fiber reinforced polymers, (CFRP) sheets in strengthening reinforced concrete element, has increased rapidly for the last ten years. The conventional alternative for CFRP is the use of steel plates bonded to the concrete surface or reinforced concrete, (RC) jackets. The major disadvantages of using the steel plates are refered to corrosion of steel and the need for technical labour and heavy equipment. Furthermore, RC jackets increase the column stiffness and consequently the applied forces due to earthquakes. Advantages of CFRP are the non- corrosive characteristics, high strength-to-weight ratio and good fatigue properties. These characteristics significantly increase the service life of structures compared to conventional strengthening techniques.
Square reinforced concrete, (RC), columns are commonly used in residential buildings, because it meets the architectural requirements in cases where partitions are provided in the building. Upgrading of these structures involves, increasing the ultimate carrying capacity as well as the ductility of the columns.
An experimental program undertaken at the Housing and Building Research Center, (HBRC) to study the behavior of RC square columns strengthened with .CFRP Sheets under axial loading. The program consists of a total of Fifteen RC column specimens, were tested and divided into three groups:
The first group consists of five columns without stirrups one column tested as control specimens without CFRP Sheets and the remaining four columns are strengthened by CFRP Sheets with different percentage of CFRP.
The second group consists of five columns with stirrups by spacing(30 cm) one column tested as control specimens without CFRP Sheets and the remaining four columns are strengthened by CFRP Sheets with different percentage of CFRP .
The third group consists of five columns with stirrups by spacing (15 cm) one column tested as control specimens without CFRP Sheets and the remaining four columns are strengthened by CFRP Sheets with different percentage of CFRP.
The columns were tested under monotonic uniaxial compression loading up to failure. Percentage of CFRP Sheets ,Width of CFRP Sheets, Number of Steel Stirrups systems are used. An analytical model based on the stress-strain characteristics of concrete under triaxial state of stresses is proposed to predict the behaviour of RC columns strengthened by CFRP Sheets. Different recommendations and design guidelines of square RC columns strengthened by CFRP Sheets are introduced.