Experimental Investigation of GFRP Reinforced Concrete Tensile Strength Using Brazilian Test Method

In the present study, the effects of GFRP reinforcement of concrete on its tensile behavior have been investigated employing Brazilian test method. The tensile strength of non-reinforced concrete has been compared with this value of two reinforced concrete samples which has been coated by 3% wt. and 6% wt. glass/epoxy skin. In other reinforced samples, short glass fibers (with similar weight fractions) have been used which mixed with ingredients of concrete. The Brazilian method designed for measuring the tensile strength demonstrates that non-reinforced samples have a peak of 60kN force and 82J Energy (The area under force-displacement curve), while after lateral reinforcement by glass/epoxy (with 3% wt.), the maximum force and energy increase to 120kN and 1633J respectively. On the other hand, using 6% wt. of glass/epoxy reinforcement does not have any significant growth in maximum tensile strength and energy. For another reinforcement method (composed short glass fiber with 3% wt. and concrete instead of using coating reinforcement), the maximum tensile force has a peak of 33.9KN that significantly lower than non-reinforced samples, but it has 396J energy which shows 482% increase in energy with comparison with non-reinforced concrete. For 6% weight, these values reduce importantly (8.57KN and 90J respectively). Comparing the two reinforcement methods illustrates that lateral strengthening is more efficient than using short fibers. Furthermore, using 3% wt. in lateral coating is cost-effective and suitable.