R/C Frame Structures with Beams Wrapped by Aramid Fiber Reinforced Polymer Sheets

The sustainability of a vital RC highway, which was constructed prior to the implementation of stringent seismic design codes, was assessed. The RC columns of the highway frames were strengthened by steel jacketing. Based on a subsequent evaluation of the performance of the strengthened frames, it was pointed out that members of some frames might be incapable of resisting the same seismic loads, which the strengthened columns may sustain. An experimental investigation that consisted of four small-scaled models was carried out employing reversed cyclic loading tests. Two specimens, which represent critical prototype frames were tested. The RC beams experienced shear failures at low response ratio levels. Accordingly, strengthening of the RC beams was shown to be of a significant importance. Testing of another two specimens enabled evaluating the positive features of wrapping the shear-deficient RC beams with Aramid Fiber Reinforced Polymer (AFRP) sheets as well as enabled providing practical recommendations. Moreover, analytical modeling of the highway frames utilizing FEM was performed. The numerical simulation resulted in a satisfactory accuracy of the predicted behavior. The calibrated base-line FE model was employed to quantitatively identify which of the RC beams of the prototype highway frames require wrapping with AFRP sheets.