Experimental studies on the behavior of concrete-filled uPVC tubular columns under axial compression loads

Abstract

The behavior of concrete-filled uPVC tubular columns under axial compression loads were studied experimentally by testing columns prepared from five different concrete strength classes. Accordingly, the unconfined, concrete-filled uPVC tube with and without wire-mesh reinforced mortar cover and reinforced concrete columns were evaluated. The main variables considered in this study are concrete strengthðf co Þ, uPVC thickness to diameter ratio (2t/D) and aspect ratio (h/ D). The effect of uPVC confinement on strength, ductility, energy absorption, and post-peak behavior was explored. Also, a model was developed to predict the peak strength. Results show that the uPVC confinement increased the strength, ductility, and energy absorption in between 1.28-2.35, 1.84-15.3, and 11-243 times the unconfined, respectively. The confinement performed well on increasing the strength, ductility, and energy absorption for lower concrete strength and higher 2t/ D ratios. The post-peak behavior of the stress-strain curve was affected by 2t/D and h/D ratios; an abrupt drop in the stress-strain curve was observed in specimens with lower 2t/D and higher h/D ratio. For a given value of concrete strength ðf co Þ, tensile strength f y À Á , thickness (t), diameter (D), and height (h), the stress-strain model ABOUT THE AUTHORS

Learning About Concrete-Filled Tube Using Chatgpt

“…Compressive buckling does not occur if the slenderness ratio is less than 3 [64]. [65] observed buckling failure in their specimens with aspect ratios of 6 and 8.…”

“…Nevertheless, there are studies of CFTs made of plastic tubes. PVC [23], [24], [66], uPVC [32], [65], [67], HDPE [68], and PE tubes [69] can be used. Plastic tubes offer little axial load capacity due to their low modulus of elasticity and yield strength [70].…”

Behaviour of Concrete-Filled Plastic Tube (CFPT) Embedded with Reinforcement Bar under Axial Compressive Load

“…These specimens were either with no rebar, short (h = 250 mm) or with moderate to large diameter, d = 111 and 160 mm). This failure was mainly due to the (a) internal crushing of concrete, and (b) excessive lateral expansion of the concrete core under compressive load [3]. The internal stress caused by the concrete crushing and expansion exceeded the confinement stress given by the plastic tube.…”

“…The concrete core enhances the axial load capacity and local buckling resistance of the plastic tube [2]. The plastic tube offers lateral confinement that delays the shear cracks' propagation [3]. This allows the concrete core to undergo straining and expansion beyond the elastic stage without shear failure [4].…”

A Strain model for uPVC tube-confined concrete

“…Test results show a ductile post-peak response with compression strain-softening and the formation of two peak strains. In another study (Woldemariam et al, 2020), Test results have illustrated that the uPVC confinement of concrete enhanced the ductility and energy absorption capacity by 1. 84-15.3 and 11-24.3 times over that unconfined specimens.…”