Compressive behavior of FRP-confined concrete-filled PVC tubular columns

Abstract

This paper presents a new composite confinement system of FRP wrap and PVC tube with and without an impact absorption medium (compressible foam) in between. The compressive behavior of the proposed FRP-confined concrete filled PVC tube (CCFPT) was investigated and compared with those of the concrete filled PVC tube (CFPT) and FRP-wrapped (FW) concrete cylinder. The effect of compressible foam on the post-peak behavior of the CCFPT specimen was explored. The applicability of seven existing FRP-confined stress-strain relationships to predict the ultimate strength and ductility enhancement of FW and CCFPT specimens was evaluated. A total of 14 FW, 5 CFPT, and 17 CCFPT specimens with 152 mm in diameter and 305 mm in height were tested under monotonically increasing axial loads in compression. The key parameters examined included the type and thickness of FRP wraps, the presence and thickness of compressible foam, and loading area. Test results indicated that, without compressible foam, the CCFPT cylinders resembled the FW cylinders in stress-strain relationships with brittle failures upon FRP rupture and immediately-followed PVC fracture due to sudden transfer in confining pressure. With compressible foam, the CCFPT cylinders can combine the strength of the FW cylinders and the ductility of the CFPT cylinders.

Structural Performance of uPVC Confined Concrete Equivalent Cylinders Under Axial Compression Loads

“…However, knowledge on the use of plastic tubes in construction is scattered and lacks information regarding how to design a concrete confined in a plastic tube [1,2].Un-plasticized polyvinyl chloride (uPVC) is a family of polymers that is made from a chain of a long hydrocarbon and it is the most commonly used polymer families for plumbing purposes. When compared to polyvinyl chloride (PVC), uPVC is strong, stiff, hard, and does not burn by itself [2][3][4][5][6][7][8]. uPVC is resistant to corrosion, abrasion, acids, salts, and bases, which provides the advantage of its use as a structural material in any such environment [1,2].…”

“…However, the use of uPVC pipes as a concrete confining material is at its very beginning and the amount of information on how to design and use it in construction is very limited. It has been established that providing a uPVC lateral confinement can enhance the strength and ductility of concrete [4][5][6]9,[17][18][19]. Gupta and Verma [8] investigated the durability through submerging the PVC confined RC column for six months into a salt concentration, which is more than 20 times more so than natural seawater.…”

Investigation on Hysteretic Behavior of Embedded PVC Pipe Confined Reinforced High Strength Concrete Columns

“…The equivalent damping ratio h e is usually used, as shown in Figure 10. The equivalent damping ratio is calculated using Equation (2). The influence of various design parameters on the energy dissipation capacity of a specimen is shown in Figure 11.…”

“…Owing to the advantages of high strength, little deformation, and good durability, reinforced high-strength concrete (RHC) is widely used in long-span, heavy-duty, and high-rise buildings [1][2][3]. However, with the increase of concrete strength, the frangibility increases and plastic deformation ability decreases.…”

Axial compressive stress-strain relation and Poisson effect of structural lightweight aggregate concrete

“…Especially, for the concrete confined by the steel tube or FRP, the expansion of concrete shall lead lateral pressure acted on the concrete, which results in significant improvement of the strength and ductility of concrete [17][18][19][20]. However, comparably rare work has been carried on the Poisson effect of LWAC.…”