Test on Seismic Performance of RC Circular Piers Strengthened with Pre-stressed CFRP Belts

Aimed at the failure modes of piers in earthquake, considering the influence of axialcompression ratio, pre-stress of carbon fiber reinforced polymer (CFRP) belts, layers of CFRPbelts and loading sequences, test on nine RC piers strengthened with pre-stressed CFRP beltsunder lateral low cyclic load and constant axial load was carried out. By comparing the failuremodes and hysteresis curves of the specimens, the influence of each parameter on the bearingcapacity, ductility, hysteretic behavior and energy dissipating capacity was analyzed. The resultsshow that the bearing capacity, ductility and energy dissipating capacity of the strengthened piersare improved significantly. The diagonal shear cracking can be inhibited by the lateral activeconfined stress provided by pre-stressed CFRP belts, and then the failure mechanism of thespecimens strengthened with pre-stressed CFRP belts can be changed from shear to flexure whichis of satisfactory ductility. Compared with the sequence of strengthcning with pre-stressed CFRPbelts at first and then exerting axial load, the sequence of exerting axial load at first will decrease the bearing capacity of the specimens.