Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 52 1 2020 03 20 An Experimental study on the behavior of circular RCC enclosed GRP casing and FRP wrapping An Experimental study on the behavior of circular RCC enclosed GRP casing and FRP wrapping 73 88 3051 10.22060/ceej.2018.14530.5677 FA Mohsen Shafieinia Ph.D. student, Department of Civil Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran Seyed Fathollah Sajedi Associate professor, Department of Civil Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran 0000-0003-3933-2793 Seyed Vahid Razavi Toosi Invited Assistant Professor, Department of Civil Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran and Assistant Professor, Department of Civil Engineering, Jundi Shapur University of Technology, Dezful, Iran Journal Article 2018 05 30 Nowadays, strengthening of the column using fiber-reinforced polymer (FRP) composites is considered as the strengthening technics of these loading elements in a structure. In this technique, increasing the surrounding pressure on radial levels of the concrete column increases the compressive and tensile strengths of the concrete element, reduces slenderness, and increases the buckling load and ductility of this element. Moreover, using glass-fiber reinforced plastic pipes (GRP) as the concrete column casing in addition to the independence of the need for framing leads to confinement effect on the concrete, high ductility and energy absorption, reduction in shrinkage and creep of concrete, lack of contact of the concrete with the corrosive factors, high construction speed, and proper loading capacity. In this research, a compressive capacity test was conducted on 6 cylinders reinforced concrete columns (RCC) of 150 mm and diameter 600 mm height, with and without GRP casing, and the effect of FRP wrapping was studied on them as the confining factor. The research results showed that using FRP wrapping and GRP casing improved the compressive capacity and ductility of the RCC. Adding one or two FRP wrapping layers increased the compressive capacity by 18.5% and 26.5% on the average, while using GRP casing increased the compressive capacity up to 4 times on the average and this shows that although FRP wrapping and GRP casing are both confined, GRP casing is more effective in increasing the compressive capacity due to its higher confinement with RCC. Nowadays, strengthening of the column using fiber-reinforced polymer (FRP) composites is considered as the strengthening technics of these loading elements in a structure. In this technique, increasing the surrounding pressure on radial levels of the concrete column increases the compressive and tensile strengths of the concrete element, reduces slenderness, and increases the buckling load and ductility of this element. Moreover, using glass-fiber reinforced plastic pipes (GRP) as the concrete column casing in addition to the independence of the need for framing leads to confinement effect on the concrete, high ductility and energy absorption, reduction in shrinkage and creep of concrete, lack of contact of the concrete with the corrosive factors, high construction speed, and proper loading capacity. In this research, a compressive capacity test was conducted on 6 cylinders reinforced concrete columns (RCC) of 150 mm and diameter 600 mm height, with and without GRP casing, and the effect of FRP wrapping was studied on them as the confining factor. The research results showed that using FRP wrapping and GRP casing improved the compressive capacity and ductility of the RCC. Adding one or two FRP wrapping layers increased the compressive capacity by 18.5% and 26.5% on the average, while using GRP casing increased the compressive capacity up to 4 times on the average and this shows that although FRP wrapping and GRP casing are both confined, GRP casing is more effective in increasing the compressive capacity due to its higher confinement with RCC. https://ceej.aut.ac.ir/article_3051_f0b1d5879866f2c2eba77f39993d1184.pdf