DISPLACEMENT BASED EVALUATION FOR CONFINEMENT REQUIREMENT OF BOUNDARY ELEMENTS OF SHEAR WALL AND RETROFIT DESIGN USING CARBON SHEET (CFS)
Supervisor: Taiki SAITO
An analytical procedure to determine the need for concrete confinement at the boundaries of the RC structural walls subjected to earthquake load is presented by relating the displacement demand of the building system to the local deformation in the wall cross section. The primary variables used to determine the need for confinement are the ratio of wall cross sectional area, the wall axial load and the wall reinforcement ratio. The validity of the approach is demonstrated by evaluating two existing buildings in Bangladesh and also by comparison with the experimental result of a two-third scale shear wall conducted in this study.
Parallel to the evaluation of need for confinement at the boundaries of the shear wall, experimental study has also been performed to evaluated the effectiveness of using externally bonded carbon fiber sheet (CFS) to increase the confinement of boundary elements of the shear wall. The experimental program comprises three two-third scale wall panels representing the control wall and two CFS-retrofitted wall panel using two different retrofit schemes. Based on the procedure in ACI 440.2R-08 for strengthening RC structures by externally bonded FRP systems an analytical procedure for retrofit design of shear wall to improve the ductility has been presented and verified by the experimental results.