Two-way walls with cut-out openings strengthened by fiber-reinforced polymers

In refurbishment projects structural modifications may be required such as the addition of new openings. These openings are a source of weakness and can reduce the structures’ stiffness and load-bearing capacity. As a result repairing may be necessary to restore their initial performances. The paper presents results of an experimental program performed to investigate the effectiveness of FRP-based strengthening for restoring the axial capacity of a solid reinforced concrete wall after cutting door openings. Nine half scale concrete walls with and without cut-out openings subjected to a uniformly distributed axial load with a small eccentricity were tested to failure. Increases in axial strength, ductility, steel reinforcement and FRP strain utilization were measured and presented in this paper. The application of the FRP confinement increases the capacity and the stiffness of the specimens with cut-out openings. The axial strengths were between 85-94.8% and 56.5-63.4% for specimens having a small and large opening, respectively, of that of a solid wall.