This paper investigates the effectiveness of strengthening reinforced concrete (RC) dapped-end beams using carbon fiber reinforced polymers (CFRP). Parametric studies are performed by means of numerical simulations in which several types of composite materials as well as their orientation are combined. The primary objectives of this research were the evaluation of the strengthening systems in terms of ultimate capacities and the failure modes involved. Results show that only some of them provide significant load bearing capacity increase. The observed failure modes ranged from a sudden failure up to the desired progressive failure of the strengthening system.