An emerging technique for strengthening of reinforced concrete (RC) slabs is to add a layer of Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) with steel rebars as an external tensile flexural reinforcement. This paper presents the results of an experimental campaign to study the structural response of composite UHPFRC-RC beams. The resistance of the UHPFRC layer subjected to combined tension and bending controls the structural response. The results show that the UHPFRC layer increases the member shear strength without impairing the deformation capacity. The Critical Shear Crack Theory is used to show the enhanced response of the composite beams.