THE CAPACITY OF REINFORCED CONCRETE BEAMS POST REBARS YIELDED WITH FRP SHEET STRENGTHENING

Structure reinforcement is usually conducted as a preventive step before structure destruction. Meanwhile, repairing structure are applied to buildings that have been destructed, as the attempt to restore the function of the structure as before after experiencing a decrease in strength. The use of fiber reinforced polymer (FRP) sheet material to restore the impacted structural capacity is increasingly considered today because it has a high strength to weight ratio, high corrosion and fatigue resistance, ease of transportation and ease of application and adjust the shape of structure. Therefore, this research was aimed to evaluate the flexural capacity of post rebar was yield, by strengthening the GFRP and CFRP sheets, as well as GFRP straps. Test specimens were using reinforced concrete beams with dimensions of 15 cm x 20 cm x 330 cm. In the flexural area of the beam reinforced with variations in GFRP and CFRP sheets. Meanwhile, GFRP straps are installed with variations in width of 300 mm and 600 mm. Before strengthened, reinforced concrete beams are loaded until reach the yield limit of the tensile reinforcement. The results showed that the use of CFRP in the tensile area significantly increased load capacity compared to GFRP, and the addition of strap width was less effective in increasing load capacity. In addition, the crack pattern on all specimens are flexural crack pattern as it is indicated by propagate cracks in a vertical direction from the tensile area to compressive side.