Sharif Digital Repository

Strengthening and rehabilitation of concrete structures significantly became a dynamic construction field of activity through the years. Strengthening concrete structures by means of fiber reinforced polymers (FRP) plates or sheets over the tensile face of flexural members is stated to be an effective rehabilitation technique. Numerous studies have been carried out over the years, taking into account the FRP strengthening methods. In this regards, premature failures induced as a result of composite plate de-bonding is of great importance in such members.
In a reinforced concrete beam de-bonding may be induced by a major flexural crack in the mid-span.
Loading of a FRP strengthened... 

In this study the behavior of steel bracings under cyclic loading, is modeled with finite element method. Analysis have shown that after local buckling in plastic mid-span position, due to the severe geometry change, the strain grows rapidly, The sharp growth of plastic strains is entitled as strain rises. Geometry change created will cause the collapse brace speeding up. In fact, the main local buckling can be used as a determinative factor in performance base design for steel braces. So the thesis has been investigated, using the parameters fracture life to quantify local buckling and fracture. Also with using the CVGM model, the fracture of the brace could be predicted. The analytical... 

Through the recent years application of FRP material in structural engineering has been developed significantly. According to possible changes of a building function during its lifetime or alteration of the building codes, building structures usually need to be strengthened. Referring to merits of FRP material, its application seems to be a convenient idea toward the cited requirement. Curved beam and slab are known as highly used elements in building structures. Bridges composed of horizontal or vertical arches could be noted as common examples which need to be reinforced by FRP. However curved concrete surfaces, reinforced by FRP plates, seem to be studied than it is really required; For,... 

In recent years, the development of the plate bonding repair technique has been shown to be applicable to many existing strengthening problems in the building industry. This technique may be defined as one in which composite sheets or plates of relatively small thickness are bonded with an epoxy adhesive to, in most cases, a concrete structure to improve its structural behaviour and strength. The sheets or plates do not require much space and give a composite action between the adherents. The old structure and the new bonded-on material create a new structural element that has a higher strength and stiffness than original one. According to the available methods of analysis and design for...