Seismic retrofit of R/C beams by wrapping potential plastic hinge zones with CFRP

Abstract

Plastic hinge investigations have been of great interest for structural engineers and researchers for years. The plastic deformation occurs in a small zone after the yielding of the bar in flexural members. Therefore, protecting this potential plastic hinge region in an economical and effective way is a very challenging topic. Knowing that CFRP is one of the lightest, strongest and easiest materials for site applications, an investigation about the confining effect of CFRP wraps on potential plastic hinge zone using different wrapping configurations was conducted. This work was based on the study of 5 reinforced concrete T- beams to account for slab interaction, one of them was designed based on the latest seismic provisions recommended by ACI, the other 4 were designed based on gravity loads without any additional confining reinforcement representative of the existing typical buildings; one of the four beams was taken as a reference and the other three were wrapped with CFRP using different wrapping configurations. Results have shown the competency of all wrapping formations of CFRP in relocating the plastic hinge away from the potential plastic hinge zone.