International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 05 | May -2017
p-ISSN: 2395-0072
www.irjet.net
EXPERIMENTAL STUDY ON FRP-PVC CONFINED CIRCULAR COLUMNS Asisha Mary Mammen1, Minu Antony2 1PG
Student, Civil Engineering Department, Saintgits College of Engineering,Kottayam, India Professor, Civil Engineering Department, Saintgits College of Engineering, Kottayam, India ---------------------------------------------------------------------***--------------------------------------------------------------------2Assistant
Abstract - Columns are main structural components which are subjected to various threats. In the Proposed system, concrete filled PVC tubes with various thickness are wrapped with GFRP (Glass Fibre Reinforced polymer) and CFRP (Carbon Fibre Reinforced Polymer). The confinement patterns are made in a helical and circular manner with two different hoop spacing so as to reduce the amount of FRP required. This system can be used in low cost construction works as an economic alternative for steel tube columns. It also acts as a cast in place form work which solves the issue of inability of steel tubes to resist corrosion. The PVC lies at the outer perimeter where it performs most effectively in tension. FRP provides additional stiffness to the PVC tubes. Effect of confinement on concrete core due to PVC pipes of various thickness (3.7mm, 5.4mm, 8.7mm) and different hoop spacing(50mm and 25mm) of FRP wrapping are studied. Comparative study on effects of confinement resulted that the specimen with larger PVC thickness and carbon fibre circular wrapping resulted in higher strength than the other specimens. Key Words: CFRP, Circular and helical wrapping, hoop spacing.
1.INTRODUCTION
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Incorporation of FRP along with PVC can enhance the axial load carrying capacity and prevents local bulging of PVC tubes. In this study the variations in the axial load carrying capacity of PVC-FRP confined columns under the variation of different parameters is studied. The parameters are the variation in 1) different gauges of pipe,2) wrapping pattern of the FRP material ie; circular and helical confinement pattern,3) hoop spacing of the wrapping, 4) and the material used for wrapping( ie; GFRP and CFRP).
1.1 Objective
Lateral confinement by a jacket has been a proven method of increasing the strength, stiffness ductility and long term performance of concrete members. This method can be use d irrespective of the type of concrete such as self compacting concrete, recycled aggregate concrete etc. studies have been extensively done on various forms of jacketing for rehabilitation and strengthening of new as well as existing structures. The new materials used for these purposes include steel spirals, steel stirrups, hollow tubes, pre stressing strands, Fibre reinforced polymer materials, FRP tubes, shape memory alloy wraps, composite ropes etc. Past studies done on confining systems along with concrete filled tubes and steel or FRP material showed improvement in lateral load resisting system and gravitational effects. Studies have been done on concrete filled steel tubes and concrete filled FRP tube systems under static and seismic loading conditions. Studies revealed that concrete filled tube systems(CFT’s) can improve the structural performance. Concrete filled systems especially steel tubes and FRP confinement has proved their load bearing capacity and lateral load resistive efficiency. The above two methods are not acceptable when considering their economic aspects. © 2017, IRJET
RCC members are always prone to environmental effects, PVC confinement can be an effective solution to safeguard members under severe environmental condition, especially in marine environments. The major advantages of PVC are high electrical insulation, low diffusion of humidity, resistance to water, acids and bases, workability including cutting, joining etc. The proposed system can act as a cast in place formwork ie; no additional formwork is required for the casting works and thus need not to remove it. The amount of water required for curing can be saved in this system since the water used for the concrete mix itself is enough for the hydration process. No water is getting escaped to the atmosphere since there is no exposure for the concrete surface.
Impact Factor value: 5.181
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The objectives of the work done are as follows:
To obtain the axial compressive strength of circular concrete columns due to FRP-PVC confinement
To compare the effect of confinement due to different gauges (wall thickness) of pipes.
To study the effect of variation in confinement due to GFRP and CFRP under different hoop spacing.
To compare the confining actions of
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GFRP on circular and helical pattern of confinement.
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CFRP on circular and helical pattern of confinement
To obtain the stress-strain behaviour of the specimens.
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