Effect of fiber angles on normal- and high-strength concrete-filled fiber-reinforced polymer tubes under monotonic axial compression

2019 ◽  
Vol 23 (5) ◽  
pp. 924-940
Author(s):  
Bing Zhang ◽  
Xia-Min Hu ◽  
Qing Zhao ◽  
Tao Huang ◽  
Ning-Yuan Zhang ◽  
...  
Keyword(s):  
Axial Compression ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Compression Tests ◽  
Absolute Value ◽  
Strength Concrete ◽  
Reinforced Polymer ◽  
Polymer Tube ◽  
Polymer Tubes

Concrete-filled fiber-reinforced polymer tubes are a novel form of composite columns, which are particularly attractive for structural members in harsh environments and seismic regions due to their corrosion resistance and ductile behavior. Over the past two decades, many studies have been conducted on concrete-filled fiber-reinforced polymer tubes under axial compression, and many stress–strain models have been proposed. However, existing studies mainly focused on concrete-filled fiber-reinforced polymer tubes with only hoop fibers. In order to investigate the effect of fiber angles (i.e. the fiber angle between the fiber orientation and the longitudinal axis of fiber-reinforced polymer tube), this study conducted axial compression tests of 42 concrete-filled fiber-reinforced polymer tubes with ±80°, ±60°, or ±45° fiber angles. These concrete-filled fiber-reinforced polymer tubes were constructed using normal-strength concrete or high-strength concrete. Fiber-reinforced polymer tube thickness was also investigated as an important parameter. In order to clarify the effect of fiber angles on the properties of fiber-reinforced polymer tubes, axial compression tests on 15 short fiber-reinforced polymer tubes and tensile split-disk tests on 75 fiber-reinforced polymer rings were conducted. Experimental results indicate that fiber angles had significant influences on the hoop properties of fiber-reinforced polymer tube; the confinement effect of fiber-reinforced polymer tube and the peak stress of the confined concrete decreased with the decrease of the absolute value of fiber angles, while the ultimate strain of the confined concrete increased with the decrease of the absolute value of fiber angles. Two existing stress–strain models, which were developed mainly on test results of concrete confined by fiber-reinforced polymer tubes with only hoop fibers, are capable of providing reasonably accurate predictions for concrete-filled fiber-reinforced polymer tubes with ±80° and ±60° fiber angles, but it underestimates the ultimate axial strain of concrete-filled fiber-reinforced polymer tubes with ±45° fiber angles.

Mechanical performance of glass fiber–reinforced polymer tubes filled with steel-reinforced high-strength concrete subjected to eccentric compression

2016 ◽  
Vol 20 (3) ◽  
pp. 374-393 ◽  
Author(s):  
Le Zhou ◽  
Lianguang Wang ◽  
Liang Zong ◽  
Gang Shi ◽  
Yunhao Bai ◽  
...  
Keyword(s):  
Glass Fiber ◽  
High Strength Concrete ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Polymer ◽  
Strength Concrete ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Polymer Tubes

Glass fiber–reinforced polymer tubes filled with steel-reinforced high-strength concrete are proposed as glass fiber–reinforced polymer–steel-reinforced high-strength concrete composite members. Eccentric compression is a typical loading scenario for such column members in practice. Experimental investigation on eight glass fiber–reinforced polymer tubes filled with steel–reinforced high-strength concrete columns subjected to eccentric compression was conducted. The effects of fiber orientation, thickness of glass fiber–reinforced polymer tube, slenderness ratio of columns, and loading eccentricity were investigated. It was found that the compression bearing capacity of glass fiber–reinforced polymer–steel-reinforced high-strength concrete columns increased with the decrease in the fiber tangle angle and the increase in the thickness of the glass fiber–reinforced polymer tube but reduced with the increase in the eccentricity and the slenderness ratio. Corresponding formulas were developed based on the nonlinear full-process analysis theory to describe the compression behavior of glass fiber–reinforced polymer–steel-reinforced high-strength concrete under eccentric loading. Good agreement was found through the comparison between the theoretical and the experimental results. The validated modeling approach was, therefore, employed to develop a parametric analysis that can be used to provide valuable guidance for practical application and further research on such structural members.

scholarly journals High-strength steel plates in hybrid fiber-reinforced polymer–concrete–steel columns: Concept and behavior

2016 ◽  
Vol 20 (5) ◽  
pp. 797-811 ◽  
Author(s):  
Tao Yu ◽  
Lip H Teh ◽  
Muhammad NS Hadi
Keyword(s):  
High Strength Steel ◽  
Steel Plate ◽  
High Strength ◽  
Steel Plates ◽  
Fiber Reinforced Polymer ◽  
Polymer Concrete ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Polymer Tube ◽  
Polymer Tubes

Applications of high-strength steel products in civil engineering have been limited by elastic local buckling, by the perceived lack of ductility, and by the perceived difficulties of welding such steels. This article proposes a new column (i.e. high-strength steel plate–concrete-filled fiber-reinforced polymer tube) consisting of an outer fiber-reinforced polymer tube, concrete infill, and encased high-strength steel plates that are connected to each other by bolted angle brackets at discrete elevations. The column offers an ideal opportunity for the use of high-strength steel plates in construction, with their high yield stresses being fully utilized and without welding (and without welding residual stresses). The rationale for the column form and its expected advantages are explained and demonstrated through laboratory tests. Prefabricated glass fiber-reinforced polymer tubes of 1.5 and 3.0 mm thick and 203 mm diameter were infilled with concrete having a nominal strength of 32 MPa, with most specimens encasing steel plates of various configurations and yield stresses ranging from 290 to 455 MPa. Results from concentric and eccentric compression tests involving 13 specimens are presented to confirm the expected structural advantages. The results demonstrated that the concrete in the tested specimens was very effectively confined, and that buckling of all the steel plates was prevented by the encasing concrete up to and beyond the rupture of the fiber-reinforced polymer tubes, leading to full structural utilization of the construction materials and very ductile column responses under concentric and eccentric loadings. The needs for future research on high-strength steel plate–concrete-filled fiber-reinforced polymer tube columns are also discussed.

Effect of fiber angles on hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns under monotonic axial compression

2020 ◽  
Vol 23 (7) ◽  
pp. 1487-1504 ◽  
Author(s):  
Bing Zhang ◽  
Jun-Liang Zhao ◽  
Tao Huang ◽  
Ning-Yuan Zhang ◽  
Yi-Jie Zhang ◽  
...  
Keyword(s):  
Fiber Reinforced Polymer ◽  
Polymer Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Absolute Value ◽  
Tubular Columns ◽  
Reinforced Polymer ◽  
Double Skin ◽  
Polymer Tube ◽  
Hoop Direction

Hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns are a novel form of hollow columns that combine two traditional construction materials (i.e. concrete and steel) with fiber-reinforced polymer composites. Hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns consist of an inner tube made of steel, an outer tube made of fiber-reinforced polymer, and a concrete layer between the two tubes. Existing studies, however, are focused on hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns with fibers of the fiber-reinforced polymer tube oriented in the hoop direction or close to the hoop direction. In order to investigate the effect of fiber angles (i.e. the fiber angle between the fiber orientation and the longitudinal axis of the fiber-reinforced polymer tube), monotonic axial compression tests were conducted on hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns with an fiber-reinforced polymer tube of ±45°, ±60°, or ±80° fiber angles. There were two types of steel tubes adopted for these hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns. The fiber-reinforced polymer tube thickness was also investigated as an important parameter. Experimental results showed that the confinement effect of the fiber-reinforced polymer tube increased with the increase of the absolute value of fiber angles, whereas the ultimate axial strain of hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns decreased with the increase of the absolute value of fiber angles. An existing stress–strain model, which was developed on the basis of hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns with an fiber-reinforced polymer tube of ±90° fiber angles, is verified using the test results of this study. For the compressive strength of the confined concrete in hybrid fiber-reinforced polymer–concrete–steel double-skin tubular columns, the existing model provides conservative predictions for specimens with a ±80° fiber-reinforced polymer tube, overestimated predictions for specimens with a ±60° fiber-reinforced polymer tube, and close predictions for specimens with a ±45° fiber-reinforced polymer tube.

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