Fatigue behavior of RC T-beams strengthened in shear with CFRP sheets

The objective of this research is to study the fatigue performance of reinforced concrete (RC) T-beams strengthened in shear with Carbon Fiber Reinforced Polymer (CFRP) composite. Experiments were conducted on RC beams with and without CFRP sheets bonded on their web surfaces and subjected to static and cycling loading. The obtained results showed that the strengthened beams could survive one million cycles of cyclic loading (=50% of maximum static load) with no apparent signs of damage (premature failure) demonstrating the effectiveness of CFRP strengthening system on extending the fatigue life of structures. Also, for beams having the same geometry, the applied strengthening technique can significantly enhance the cycling load particularly, in case of beams provided with U-jacket sheets. Moreover, although the failure mode for the different beams was a brittle one, the strengthened beams provided with U-jacket sheets approved an acceptable enhancement in the structural ductility.