Flexural and shear strengthening of reinforced concrete beams with a hybrid CFRP solution

Abstract

An experimental program was carried out for assessing the performance of a hybrid solution composed by CFRP systems for the simultaneous flexural and shear strengthening of RC beams. CFRP laminates, applied according to NSM technique, are used for the flexural strengthening, while U-shape CFRP discrete strips of wet lay-up sheet, applied according to the EBR technique, are adopted for the shear strengthening. An anchorage system was applied at the extremities of these CFRP strips in an attempt of avoiding their premature debonding. The experimental results showed the hybrid strengthening solution is very effective, not only in terms of increasing the load carrying capacity of the beams, but also in assuring higher mobilization of the tensile capacity of the CFRP. The performance of the hybrid CFRP configuration that included the anchorage system for the shear strengthening was significantly higher than the one assured by other shear strengthening solutions that were applied in similar RC beams and tested until failure using the same test system adopted in this experimental program. The predictive performance of the ACI formulations proposed for estimating the contribution of CFRP systems for the flexural and shear resistance of RC beams was appraised considering the obtained experimental results.