Because of the shortcomings of the externally bonded system that mainly consists of epoxy and FRP sheets, the fabric-reinforced cementitious matrix, (FRCM) represents a viable solution in the strengthening of reinforced concrete beams. The FRCM layers consist of fabric mesh embedded in an inorganic stabilized cementitious mortar. Many experimental studies examined the impact of strengthening of RC beams with the FRCM layers, but the numerical investigations are limited. This study is therefore aimed at introducing a numerical study investigating the behavior of RC beams reinforced with FRCM layer. The main goal of this paper is to verify the FEM results with the experimental results that are available in the previous study [1], and to provide a parametric study. The investigated beams in this paper are 150 mm × 250 mm× 3000 mm with two reinforcement ratios. One, two, and three-layers of PBO, (P-Phenylene Benzobis Oxazole) FRCM were investigated as strengthening of the simulated beams were strengthened with. The numerical validation included load-deflection curve, load –strain of both concrete and PBO- FRCM, strain distribution, cracks series and failure mode. The built model gave an accurately prediction of the attitude of the investigated beams. The results also indicated that the rise in the reinforcement ratio or the amount of FRCM layers contributed to improving behavior under both ultimate and serviceability limit states.