External strengthening of Reinforcement Concrete (RC) structures using epoxy-bonded Fiber Reinforced Polymer (FRP) sheets has some negative aspects, such as interfacial debonding and poor resistance ability of epoxy resin for fire and ultraviolet (UV), in addition to the working environment restrictions. To overcome some of those negative aspects, FRP grid bonded with Polymer Cement Mortar (PCM) to strengthen RC structures is developed and proposed in this study. The main objective of this paper is to study the efficiency between Basalt FRP grids and PCM in the flexural strengthening of RC beams. A tensile test was first conducted to determine the static longitudinal tensile strength and maximum elongation properties of the different BFRP grids. Then, the well-known double shear test was conducted to determine the bond mechanism between BFRP grids and concrete. Finally, the flexural behavior of the RC beam externally strengthened with BFRP grids was investigated through a four-point bending test. The results showed the efficiency of using BFRP grids as external strengthening method, as well as the stress-strain relationship of RC beams cross-section shows the compatibility with flexural theory.