Enhancement of the Tensile Strength of Reinforced Concrete Beams Using GFRP

Use of externally bonded Glass Fiber Reinforced Polymer (GFRP) sheets/strips/plates is a modern and convenient way for strengthening of RC beams. GFRP can be classified as a type of composite material that is increasingly used in the construction industry in recent years. Due to their light weight, high tensile strength, corrosion resistance and easy to implementation makes these material preferred solutions for strengthening method of reinforced concrete structural elements. This paper presents the experimental results on the confining effects of GFRP wraps in the tension-zone of reinforced concrete RC beams. A total of 16 beam specimens were used in this study. The beam dimensions were 150 mm width, 150 depths, and 620 span lengths center to center with total length 700 mm. The test parameters include number of layers and width of GFRP. The GFRP laminates were applied 580 mm in length. The specimens were tested in four points bending to failure. This paper provides new information on the degree of GFRP enhancement for reinforced concrete members and the effect of the GFRP wrapping width and layers, and increase in capacity to prevent cracks in tension zone with and without GFRP wrapping. The results of tests have been evaluated and compared with international codes. Consequently it has been noted that the GFRP materials enhance both strengthening and ductility of reinforced concrete beam sections. When trying to utilize fiber polymer sheets, either made of carbon CFRP or steel SFRP, as external shear reinforcement attached on RC beams, their potential of high tensile strength is prevented by the GFRP sheets.