Effect of column-to-beam strength ratio on seismic performance of RC frames with FRP wrapped column

摘要

The aim of this paper is to study the influence of column-to-beam strength ratio on seismic strengthening of column with FRP wrapping system. FRP wrapped reinforced concrete (RC) columns are analyzed to obtain moment-curvature curves using CFRP confined concrete characteristics. The variables were axial load, longitudinal steel ratio and ratio of confining pressure to unconfined concrete strength. Results show that increase in confining pressure increases ductility especially at low values of axial load and longitudinal steel ratio. Push-over analysis was performed on one and three-story moment-resisting frames with different column-to-beam strength ratio. The results indicate that FRP strengthening is more efficient in frames with low column-to-beam strength ratio due to the type of lateral failure mechanism. In frames with column stronger than beam's, beyond a confining pressure ratio, further performance enhancement will not be achieved. Therefore in strengthening design, column-to-beam strength ratio controls the level of effective wrapping.