FRP strengthening of RC walls with openings

Strengthening reinforced concrete (RC) walls with openings using fibre reinforced polymers (FRP) has been experimentally proven to be a viable rehabilitation method. However, very few theoretical investigations are reported. In this paper two methods of analysis are presented. Since openings vary in size, the analysis of a strengthened wall can be divided into frame idealization method for large openings, and combined disk and frame analysis for smaller openings. The first method provides an easy to use tool in practical engineering, where the latter describes the principles of a ductile strengthening method, relying on dislocation of yield lines and creation of a new yield mechanism. The frame idealization method can be considered as a safe guideline for real strengthening projects based on commonly used principles. The principles in the latter are new and promising, but need experimental verification before use in strengthening projects.