Experimental and Numerical Investigation of Two Fixed-End RC Beams Strengthened With CFRP Bars in NSM Method

Fiber reinforced polymer (FRP) material is currently being produced in different configurations and widely used to strengthen and retrofit concrete structures and bridges. It is also possible to apply other strengthening methods without changing the appearance or the dimensions of the structure. Near Surface Mounted (NSM) is a recent strengthening method using CFRP bars (rods or laminate strips) bonded into pre-cut grooves applied to the concrete cover of the elements to be strengthened. These FRP bars can also help increase flexural and shear capacity of existing concrete members. This paper aims to present the experimental and numerical results gained separately from un-strengthened and strengthened beams under bending loading. In the experimental part, two large-scale fixed-end support reinforced concrete beams of the same size and reinforcement characteristic were designed, constructed, and tested under one point concentrated loading system. The first specimen used as a control specimen while the second served as the strengthened using NSM method with a new proposed hand-made CFRP Bar in the laboratory. Moreover; an extra analytical work was carried out using calibration of the analytical models as per the obtained experimental test results. The results and Photographs taken at the selected stages of loading are indicative of the fact that NSM method with FRP bars can be effectively applied to the existing structures in order to increase their flexural capacity, change their crack pattern and decrease final deflection.