Abstract: To investigate the bond performance and flexural strength of R.C.beams strengthened with CFRP sheets under dynamic loads,five reinforced concrete(RC)beams with epoxy-bonded carbon fiber reinforced plastic(CFRP)sheets were loaded with sinusoidal fatigue loads that simulate traffic loads.One RC beam strengthened with CFRP sheets under sustaining loads and two contrastive RC beams were also experimentally investigated.Variables considered in this experimental program includes compressive strength of the concrete,reinforcement ratio,anchorage system,bonded length,and load range.The dynamic results generally indicate that the flexural strength of the repaired beams under simulated traffic loads is increased,and bond performance between CFRP and RC beams is good.The results also demonstrate the feasibility of rehabilitating and strengthening damaged RC beams with CFRP sheets while the beams are under dynamic loads.The static test program shows that the application of CFRP to RC beams results in increased strength and enhanced performance.