Performance of Circular Concrete-Filled FRP-Grooved Steel Composite Tube Columns under Axial Compression

Abstract

A new structure termed “concrete-filled FRP-grooved steel composite tube (CFGCT) column” is proposed, which is composed of a stress-released steel tube (i.e., grooved steel tube), fiber-reinforced polymer (FRP) and concrete. Axial load tests were carried out on twenty-four specimens to investigate the constraint effect of this structure. Three main experimental variables were considered: the steel tube thickness, the FRP type, and the FRP layer. The failure modes, stress-strain relationships and the effect of the main experimental variables were discussed. The stress-strain curves of this new structure are composed of an initial linear part, a nonlinear transition part, a strengthening part and a residual part. The test results demonstrate that the bearing capacity of the structure was improved, and that the mechanical mechanism of the structure was simplified due to the stress-released grooves. Based on the test results and previous studies, formulas for calculating the ultimate stress (fcu), ultimate strain (εcu), peak stress (fcc) and peak strain (εcc) were proposed. In addition, models for predicting the stress-strain curves of CFGCT columns were put forward, and the models could precisely simulate the stress-strain curve of this new composite structure. Hence, this study indicates that a structure composed of FRP and stress-released steel tube can effectively constrain concrete.

Experimental-numerical study on axial compression performance of square concrete columns confined by new-type BFRP

“…, frp e and the effective tensile strain coefficient k e needs to be introduced to reflect the reduction range of the actual destructive strain [72], that is:…”

Research on Hysteretic Behavior of FRP-Confined Concrete Core-Encased Rebar

“…FRP has been widely used in construction projects in recent years due to its excellent lightweight, high-strength, corrosion resistance, and ease of cutting properties [ 14 ]. Extensive research has been carried out on the application of FRP materials on building structures and reinforced concrete structures [ 15 , 16 , 17 , 18 , 19 ]. As can be seen, FRP materials are widely used in the field of construction engineering due to their unique advantages.…”

Modeling and Calculation of Improved Centrifuged Reinforced Concrete Columns with Variotropic Structure

“…Many works are devoted to the study of the behavior of concrete and reinforced concrete columns under axial loading [29][30][31][32]. At the same time, numerical simulation methods [33][34][35], experimental methods [31], and complex methods are widely used to confirm the created models [29,30,[36][37][38][39][40][41][42]. The material of the columns is also quite diverse in these studies.…”

“…The material of the columns is also quite diverse in these studies. This can be ordinary reinforced concrete [29,30,32], high-strength concrete [31], high-strength steel-reinforced concrete [30,36], reinforced concrete from steel pipes with concrete filling [33][34][35]38,40,41], other types of concrete (fiber-reinforced, geopolymer [39], fiberglass [37], and others with various formulation solutions). Differences in existing studies also lie in the size of the columns.…”

“…The objects of simulation and experimental study were both full-sized [35] and short [36] columns. In addition, mechanical [36] and operational [37] characteristics of columns under the action of axial load were calculated.…”