Experimental and analytical study on the flexural performance of CFRP- strengthened RC beams at various pre-stressing levels

摘要

This work aimed to evaluate the flexural performanceof RC beams strengthened by carbon fibre-reinforced polymer (CFRP) plates, which were applied at the soffit of beams and pre-stressed at various levels. Six RC beams were prepared that were pre-stressed at 0, 20 and 40% of the ultimate strength of the CFRP plate, and they were subjected to four-point bending tests to evaluate the cracking load, yield load, and ultimate load of the beams. The variation in strain of the CFRP plate and deflection were monitored under applied load. With the prestressing level, it was observed that all types of the aforementioned loads were increased, whereas the deflection and ductility were decreased. Cracking moment was evaluated analytically by proposing one modification factor into existing equation that was obtained by regressing the data of 41 analogous RC beams. Modified equation was also verified by the calculated deflection, which have close resemblance with the experimental observations.