Ozbakkaloglu, Togay2013-11-082013-11-0820052005Source: Dissertation Abstracts International, Volume: 66-12, Section: B, page: 6794.http://hdl.handle.net/10393/29245http://dx.doi.org/10.20381/ruor-19666The use of high-strength concrete (HSC), with strengths reaching 130 MPa, has increased in recent years due to its superior performance and strength. Structures are designed and built utilizing HSC, especially in columns of multi-story buildings. However, the use of high-strength concrete (HSC) in seismically active regions poses a major concern because of the brittle nature of the material. The confinement requirements for HSC columns may be prohibitively stringent since they require proportionately greater confinement than columns of normal-strength concrete. An alternative to conventional confinement reinforcement is the use of fibre reinforced polymer (FRP) casings, in the form of a stay-in-place formwork. The use of stay-in-place FRP formwork as concrete confinement reinforcement for HSC columns was investigated. Large scale HSC building columns, encased in FRP casings, were tested under simulated seismic loading. The columns had 270 mm square and circular cross-sections and concrete strengths up to 90 MPa. The casings were manufactured from carbon FRP and epoxy resin. The unique aspects of the test program were the introduction of the corner radius as a test parameter, and the presence of internally placed FRP crossties in square columns, integrally built with column casings to improve the effectiveness of concrete confinement. Results indicate that the deformation capacity of HSC columns can be improved significantly by using FRP casings. The results further indicate that the confinement effectiveness of square columns is significantly affected by the corner radius of casings. Additionally, the confinement efficiency can be improved with the use of FRP crossties. The columns developed inelastic drift capacities of up to 12%, demonstrating the usefulness of FRP stay-in-place formwork in improving deformability of HSC columns. Fibre-reinforced polymer (FRP) composite casings offer an attractive alternative to conventional reinforcement to enhance strength and deformability of concrete columns. FRP casings can be designed to increase lateral deformability of earthquake resistant columns significantly, while also providing some enhancement of load-carrying capacity. There is a clear need for a design procedure to compute lateral drift capacities of FRP encased square and circular columns. A design approach was developed that incorporates experimentally observed confinement parameters, while also incorporating axial load and lateral drift as design variables. The approach had evolved from a displacement based design procedure developed for concrete columns confined with conventional steel reinforcement. The expression derived as part of the proposed design procedure had been verified against available experimental data. (Abstract shortened by UMI.)329 p.enEngineering, Civil.Thesis