Response of RC Beam-Slab Structure Strengthened with CFRP under Sudden Corner Column Removal Scenario

Reinforced concrete columns support loads from beam-slab sub assemblage of a buildings and transfer into a foundation. However, columns could also be intentionally removed due to architectural interest, accidentally lost by unexpected extreme loading such as blast or impact loading or construction error leading a structure to fail progressively. A missing corner column likely causes progressive collapse than an interior column or edge column due to relatively weak tie force from nearby structural member. Applying innovative strengthening methods such as using Carbon Fiber-reinforced polymer (CFRP) composites is one of viable options to restore or increase performance losses due to a missing column. This research work numerically investigates response of as-built and Carbon Fiber-reinforced polymer (CFRP) composites strengthened beam-slab sub assemblage under sudden corner column removal scenario. Non-linear finite element software program ANSYS is used to generate 3D model and validate experiment results reported in literature and further parametric studies are performed on retrofitting techniques to restore or enhance load carrying capacity and floor stiffness of beam-slab sub assemblage under missing column case. Finite element results indicate as compared to beam-slab sub assemblage with all columns intact, applying 16 CFRP layers (0.334mm thickness per layer) at slab top, beam side and bottom of beam-slab sub assemblage with missing corner column resulted in 87.36% gain in load carrying capacity. Also use of composites improved failure characteristics such as crack pattern, concrete damage and progressive collapse resistance of beam-slab sub assemblage.