Jordan Journal of Civil Engineering

The Behavior of Concrete-Filled Plastic Tube Specimens under Axial Load


Nwzad Abduljabar Abdulla;


Plastic uPVC tubes were used to encase concrete subjected to compression load. Two series of specimens were tested to evaluate the contribution of plastic tube (PT) to enhancing strength and improving ductility of concrete in slender specimens subjected to axial load. The first series included nine concrete-filled plastic tube (CFPT) columns with diameter-to-thickness ratio (D/t) varying from 13.8 to 22. For comparison, series two contained four concrete-only specimens with variable slenderness ratio (KL/r). At the top end, the columns were tested for rotation free and translation fixed end conditions. The main parameters of the study included the D/t ratio, the rotations of the loading platen and the length-to-diameter ratio (L/D). Deformed shape, failure mode, ultimate strength, lateral deformation, angular rotation at column end, ductility and toughness were studied. With increased slenderness, the load-carrying capacity reduced and the composite column system underwent substantial compression softening past the peak load, depending on the end rotation. The use of polymeric tube resulted in progressive failure instead of sudden and explosive failure associated with plane concrete columns. The lateral displacement at failure increased from an average of 3.4 mm for normal columns to a maximum value of 95 mm for CFPT columns (1-6). A similar trend was observed for angular rotation and ductility of the composite system, which increased by 20 and 11 folds, respectively.


Plastic tube, Failure mode, Compression softening, Length effect, Tube influence, Ductility