A Strain model for uPVC tube-confined concrete

Abstract

The brittle response of concrete largely influences concrete deformation under axial load in the post-peak descending branch of the stress-strain curve. In this study, unplasticized polyvinyl chloride (uPVC) plastic tube used to confine concrete cylinders and improve the post-peak performance of specimens subjected to axial compression loads. Three experimental parameters, tube diameter, tube thickness, and H/D ratio, used to examine the mechanical behavior of eighteen uPVC tube confined short concrete columns. Test results show that when the outer diameter to thickness ratio (D/t) changed from 22 to 12.9, local buckling of the polymeric tube decreased, and the strain at peak stress was increased. So far, there is no model for predicting the strain of plastic tube confined concrete. The present test data was combined with more than 160 test data collected from the published literature to compile an experimental database. The number of test data for the strain of uPVC tube confined concrete reported in the literature is limited and less than those for strength. However, the assembled database was abundant enough to develop an ultimate condition model for the maximum axial strain accurately, based on the database. The developed model's accuracy was verified by comparing model predictions with twenty existing FRP-confined concrete models using three statistical indices. The distinguishing feature of the strain model includes several parameters on the concrete confined by the uPVC tube.

Concrete-Filled Tubular Column Made of Various Types of Material

“…Researchers used various materials as tubes for CFTs. This included steel [2], [14] - [16], stainless steel [17] - [19], fibre-Reinforced Polymer (FRP) [7], [18], [20], High Density Poly Ethylene (HDPE) [21], Unplasticized Polyvinyl Chloride (uPVC) [5], [12], [22] - [25], and Polyvinyl chloride (PVC) [1], [10], [26] - [31]. The behavior of CFT differed owing to the unique characteristics of these materials.…”

“…C. PLASTIC TUBES Plastic materials were also used to produce CFT. There were Polyvinyl Chloride (PVC) [1], [10], [28], [58], Unplasticized Polyvinyl Chloride (uPVC) [5], [11], [12], [63], [64], High-Density Polyethylene (HDPE) [65], and Polyethylene (PE) [39]. The properties of plastic materials are given in Table 5.…”

Energy Absorption Capacity of uPVC-Confined Concrete

“…A stretching of plastic samples between 40 to 100% have been documented [13][14][15]. Such large deformation of the plastic tube is related to its plastic flow mechanism during the axial deformations of the uPVC-concrete composite system [16]. The tube influences the peak and ultimate failure load and the corresponding peak and ultimate strains increases, too [17].…”