Shear Strengthening of R/C Beams with FRP Strips and Novel Anchoring

The shear strengthening behaviour of R/C beams, when applying FRP strips externally with or without anchoring, is studied. This is done by subjecting six specimens of prototype dimensions with or without such strengthening to four-point bending. Specimens strengthened with either carbon or steel FRP strips without the use of anchors exhibited a modest increase in shear capacity, when compared to the non-strengthened control specimen, due to the debonding mode of failure of these FRP strips. The patented anchoring device was utilized together with either carbon or steel FRP strips for shear strengthening. In this case, the FRP strips debonding failure was prevented and the increase of the shear capacity was much larger than in identical specimens without anchors. An expert system developed for this purpose is quite efficient in producing successful shear capacity predictions based on the provisions of various codes. The Greek Code for retrofitting existing R/C structures yields shear capacity predictions in good agreement with measured values.