Progressive Collapse Resistance of GFRP-Strengthened RC Beam–Slab Subassemblages in a Corner Column–Removal Scenario

In RC buildings, the unexpected sudden failure of a corner column is more likely to cause severe progressive collapse than the failure of an interior column or a side column due to the relatively weak tie force from the surrounding elements. Effective strengthening methods can improve the progressive collapse resistance of these structures. Fiber-reinforced polymer (FRP) has been widely used to retrofit RC structures due to its high strength, light weight, and corrosion resistance. In this study, the progressive collapse behaviors of glass FRP (GFRP)–strengthened RC beam–slab subassemblages under corner column removal were investigated. First, a quasi-static experimental test was adopted to study the progressive collapse resistance of the beam–slab subassemblages, including a control specimen and strengthened specimens. Two techniques applying externally bonded GFRP laminates and near-surface-mounted (NSM) GFRP bars were adopted to strengthen the subassemblages. The influences of the strengthening schemes on the behavior of the tested specimens were studied by comparing all the test results. The experimental results demonstrate that this strengthening technology can enhance the progressive collapse resistance of RC beam–slab structures. Finite-element (FE) analysis of the progressive collapse resistance of the beam–slab subassemblages was also conducted using the software package MSC Marc. The numerical model can predict the progressive collapse resistance of the subassemblages. In addition, the calculated results were used to better understand the stress distribution of the GFRP in a corner column–removal scenario.