Aiming to develop an analytical solution to describe the behavior of reinforced concrete beams post-strengthened with FRP systems, with or without prestressing, a non-linear solution based on a tri-linear moment-curvature response was proposed. Three characteristic points were used to define the stages of the moment-curvature diagram: concrete cracking, steel yielding and ultimate capacity of the cross section. The load-deflection responses of the post-strengthened beams were then obtained by a double integration of the moment-curvature curve. This analytical procedure was implemented using the Matlab ® software and the results obtained have closely matched the experimental data collected in bending tests performed in concrete beams post-strengthened with post-tensioned and non post-tensioned FRP strips.
FRP; tri-linear analysis; analytical solution