Physical and mechanical performance of an innovative glass-fiber-reinforced plastic rod for concrete and grouted anchorages

Recently, consideration has been given to replacing conventional steel rebars with glass-fiber-reinforced plastic rods in specific applications such as structures subjected to corrosive or marine environment or where electrical or electro magnetic insulation is required. The paper presents the results of a laboratory investigation including physical and mechanical behaviour of a glass-fiber-reinforced plastic rod. The following tests were conducted: thermal expansion, tension at ambient and high temperatures, compression, flexure, shear, fatigue on bare rods, and pullout of rods embedded in concrete. It was found that the glass-fiber-reinforced plastic rod possessed a higher ultimate tensile stress but much lower modulus of elasticity than steel rebars. The plastic rods withstood fewer cycles than steel bars, particularly at higher levels of stress. The loss of strength at temperatures above 200 °C was found to be considerably higher than steel. The coefficient of longitudinal thermal expansion was similar to that of concrete and steel. In light of the results, examples for concrete structural elements have been illustrated in the paper. Key words: glass-fiber rod, plastic, reinforced concrete, thermal expansion, tension, compression, flexure, shear, high temperature, fatigue, pullout, bond strength, development length, beams, slabs, median barriers.