Effect of Inner Steel Tube Cross-Sectional Shape on Compressive Behavior of Square FRP-Concrete-Steel Double-Skin Tubular Columns

2015 ◽  
Vol 752-753 ◽  
pp. 578-583 ◽  
Author(s):  
Butje Alfonsius Louk Fanggi ◽  
Togay Ozbakkloglu
Keyword(s):  
Steel Tube ◽  
Experimental Program ◽  
Steel Tubes ◽  
Cross Sectional ◽  
Tubular Columns ◽  
Column System ◽  
Double Skin ◽  
Concrete Filling ◽  
Sectional Shape ◽  
The University

Recently, a new type of composite system was proposed in the form of fibre reinforced polymer (FRP)-concrete-steel double-skin tubular columns (DSTCs). The performance of this column system, which consists of an outer tube made of FRP and an inner tube made of steel, has been experimentally investigated in a number of studies. However, apart from a single study reported on square DSTCs, all of the existing studies have been concerned with DSTCs with circular external tubes. This paper reports on part of an ongoing experimental program at the University of Adelaide that was aimed at addressing this research gap. The effect of cross-sectional shape of inner steel tube on compressive behaviour of square DSTCs was investigated through the test of 16 hollow and concrete-filled DSTCs. The result of the experimental study indicate that concrete in hollow DSTCs with circular inner steel tubes develop significantly larger ultimate axial stresses and strains than concrete in companion hollow DSTCs with square inner steel tubes. On the other hand, the results also indicate that the presence of a concrete-filling inside inner steel tubes results in a significant improvement in the behavior of DSTCs with square inner steel tubes.

Influence of Concrete-Filling Inner Steel Tube on Compressive Behavior of Double-Skin Tubular Columns

2013 ◽  
Vol 838-841 ◽  
pp. 535-539 ◽  
Author(s):  
Butje Alfonsius Louk Fanggi ◽  
Togay Ozbakkaloglu
Keyword(s):  
High Strength ◽  
Steel Tube ◽  
Experimental Program ◽  
Compressive Behavior ◽  
Steel Tubes ◽  
Tubular Columns ◽  
Reinforced Polymer ◽  
Double Skin ◽  
Concrete Filling ◽  
The University

This paper reports on a part of an ongoing experimental program at the University of Adelaide on the behavior of fiber reinforced polymer (FRP)-concrete-steel double-skin tubular columns (DSTCs). Influence of concrete-filling inner steel tube on the compressive behavior of FRP-concrete-steel DSTCs was investigated experimentally through the test of 8 normal-and high-strength concrete DSTCs. The results of the experimental study indicate that concrete-filling inner steel tubes of DSTCs results in a slightly increase in the compressive strength and decrease in the ultimate strain of concrete in DSTCs, compared to companion DSTCs with hollow inner steel tubes. The results also indicate that concrete in both types of DSTCs is confined effectively by FRP and steel tubes.

Reflections on Mechanisms Affecting the Behavior of FRP-Concrete-Steel Double-Skin Tubular Columns

2016 ◽  
Vol 705 ◽  
pp. 323-331 ◽  
Author(s):  
Togay Ozbakkaloglu
Keyword(s):  
Complex System ◽  
Detailed Examination ◽  
Steel Tube ◽  
Experimental Program ◽  
System Behavior ◽  
Compressive Behavior ◽  
Tubular Columns ◽  
Double Skin ◽  
Concrete Filling ◽  
The University

This paper presents the results of 20 hollow and concrete-filled double-skin tubular columns (DSTCs), which were tested as part of a comprehensive experimental program that was undertaken at The University of Adelaide on FRP-concrete steel DSTCs. The paper is aimed at providing important insights into the influence of two key parameters, namely the diameter of inner steel tube and presence/absence of a concrete-filling inside the inner steel tube, which play major roles in the column behavior through their influences on a series of interacting mechanisms that govern the complex system behavior. A detailed examination of the results yielded a number of important insights into the mechanisms that influence the compressive behavior of DSTCs.

Influence of Inner Steel Tube Diameter on Compressive Behavior of Square FRP-HSC-Steel Double-Skin Tubular Columns

2015 ◽  
Vol 1119 ◽  
pp. 688-693 ◽  
Author(s):  
Butje Alfonsius Louk Fanggi ◽  
Togay Ozbakkloglu
Keyword(s):  
Axial Compression ◽  
Axial Stress ◽  
Steel Tube ◽  
Tube Diameter ◽  
Experimental Program ◽  
Composite Columns ◽  
Tubular Columns ◽  
Column System ◽  
Double Skin ◽  
The University

FRP-concrete-steel double-skin tubular columns (DSTCs) are a new form composite column system that effectively combines the advantages of the constituent materials. The performance of this column system has been experimentally investigated in a number of recent studies. However, apart from a single study reported on square DSTCs, all of the existing studies have been concerned with DSTCs with circular external tubes. This paper reports on part of an ongoing experimental program at the University of Adelaide on FRP-concrete-steel composite columns. The results from 12 square hollow and concrete-filled DSTCs and six companion hollow concrete-filled FRP tubes (H-CFFTs) that were tested under axial compression are presented. Results of the experimental study indicate that hollow DSTCs with larger inner steel tube diameters develop similar ultimate axial stresses to but significantly larger axial strains than companion DSTCs with smaller inner steel tubes. The results also show that, in concrete-filled DSTCs with similar Ds/ts ratios, an increase in the steel tube diameter leads to an increase in both axial stress and strain of concrete. It was observed that H-CFFTs perform significantly worse than both hollow and filled DSTCs under axial compression, and their behavior further degrades with an increase in the diameter of their inner voids.

Influence of Inner Steel Tube Properties on Compressive Behavior of FRP-HSC-Steel Double-Skin Tubular Columns

2013 ◽  
Vol 438-439 ◽  
pp. 701-705
Author(s):  
Butje Alfonsius Louk Fanggi ◽  
Togay Ozbakkaloglu
Keyword(s):  
Axial Stress ◽  
High Strength ◽  
Steel Tube ◽  
Experimental Program ◽  
Stress And Strain ◽  
Steel Tubes ◽  
Composite Columns ◽  
Tubular Columns ◽  
Double Skin ◽  
The University

This paper reports on part of an ongoing experimental program at The University of Adelaide on FRP-concrete-steel composite columns. A total of eight high-strength concrete double-skin tubular columns (DSTCs) were tested under axial compression. The column parameters examined included the diameter, thickness, and shape of inner steel tube. The results of the experimental study show that increasing the inner steel tube diameter leads to an increase in the ultimate axial stress and strain of concrete in DSTCs. The results also show that increasing inner steel tube thickness leads to an increase in the ultimate axial stress and strain of DSTCs. Furthermore, it is observed that concrete inside DSTCs with square inner steel tubes is not confined as effectively as concrete inside DSTCs with circular inner steel tubes.

An Experimental Study on Behavior of FRP-HSC-Steel Double-Skin Tubular Columns under Concentric Compression

2013 ◽  
Vol 357-360 ◽  
pp. 565-569
Author(s):  
Togay Ozbakkloglu ◽  
Butje Alfonsius Louk Fanggi
Keyword(s):  
Experimental Study ◽  
Steel Tube ◽  
Experimental Program ◽  
Steel Tubes ◽  
Composite Columns ◽  
Tubular Columns ◽  
Double Skin ◽  
Steel Composite ◽  
The University ◽  
Ultimate Condition

This paper reports on part of an ongoing experimental program at The University of Adelaide on FRP-concrete-steel composite columns. The results from eight FRP-concrete-steel double-skin columns (DSTCs) that were tested under constant axial compression are presented. The key parameters examined included diameter, thickness, and strength of inner steel tube. The results of the experimental study indicate that concrete in a DSTC system is confined effectively by FRP and steel tubes. The results also indicate that increasing the inner steel tube diameter leads to an increase in the ultimate axial strength and strain of DSTCs. No clear influence of the strength of inner steel tube is observed on the ultimate condition of concrete in DSTCs. These results are presented together with a discussion on the influence of the key parameters on the compressive behavior of DSTCs.

scholarly journals Axial Behavior of Concrete-Filled Double-Skin Tubular Stub Columns Incorporating PVC Pipes

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1434
Author(s):  
Muhammmad Faisal Javed ◽  
Haris Rafiq ◽  
Mohsin Ali Khan ◽  
Fahid Aslam ◽  
Muhammad Ali Musarat ◽  
...  
Keyword(s):  
Steel Tube ◽  
Tube Material ◽  
Steel Tubes ◽  
Tubular Columns ◽  
Axial Capacity ◽  
Double Skin ◽  
Axial Behavior ◽  
Pvc Pipe ◽  
The Cost ◽  
Stub Columns

This experimental study presents concrete-filled double-skin tubular columns and demonstrates their expected advantages. These columns consist of an outer steel tube, an inner steel tube, and concrete sandwiched between two tubes. The influence of the outer-to-inner tube dimension ratio, outer tube to thickness ratio, and type of inner tube material (steel, PVC pipe) on the ultimate axial capacity of concrete-filled double-skin tubular columns is studied. It is found that the yield strength of the inner tube does not significantly affect the ultimate axial capacity of concrete-filled double-skin tubular composites. With the replacement of the inner tube of steel with a PVC pipe, on average, less than 10% strength is reduced, irrespective of size and dimensions of the steel tube. Hence, the cost of a project can be reduced by replacing inner steel tubes with a PVC pipes. Finally, the experimental results are compared with the existing design methods presented in AISC 360-16 (2016), GB51367 (2019), and EC4 (2004). It is found from the comparison that GB51367 (2019) gives better results, followed by AISC (2016) and EC4 (2004).

Flexural Behavior of Hybrid Double-Skin-Tubular Beams

2013 ◽  
Vol 838-841 ◽  
pp. 525-529 ◽  
Author(s):  
Yunita Idris ◽  
Togay Ozbakkaloglu
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Flexural Behavior ◽  
Experimental Program ◽  
Simply Supported ◽  
Four Point Bending ◽  
Double Skin ◽  
The University ◽  
Very High

This paper reports on part of an ongoing experimental program at The University of Adelaide on the flexural behavior of FRP-high-strength concrete (HSC)-steel double-skin tubular beams (DSTBs). The results from three circular DSTBs that were tested as simply supported beams in a four-point bending setup under monotonic loading are presented. The experimental study investigated the influences of the inner steel tube diameter and the use of mechanical connectors on the steel tube on the flexural behavior of DSTBs. The results indicate that DSTBs are capable of developing very high inelastic flexural deformations. However, the results also indicate that slip between the concrete and the steel tube of the DSTB can be relatively large, unless the bond between concrete and steel tube is enhanced through the use of mechanical connectors. It was also observed that the flexural behavior of DSTBs is influenced significantly by the diameter and thickness of the inner steel tube.

scholarly journals Effect of Cross-Sectional Aspect Ratio on Rectangular FRP-Concrete-Steel Double-Skin Tubular Columns under Axial Compression

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Bing Zhang ◽  
Xia-Min Hu ◽  
Wei Wei ◽  
Qian-Biao Zhang ◽  
Ning-Yuan Zhang ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Cross Section ◽  
Axial Stress ◽  
Axial Strain ◽  
Steel Tube ◽  
Confined Concrete ◽  
Cross Sectional ◽  
Tubular Columns ◽  
Double Skin ◽  
Frp Tube

Hybrid FRP-concrete-steel double-skin tubular columns (hybrid DSTCs) are novel hollow columns consisting of an outer FRP tube, an inner steel tube, and the concrete between the two tubes. Hybrid DSTCs possess important advantages, such as excellent corrosion resistance as well as remarkable seismic resistance. However, existing studies are mainly focused on hybrid DSTCs with a circular cross section or a square cross section. When a column is subjected to different load levels in the two horizontal directions, a rectangular column is preferred as it can provide different bending stiffness and moment capacity around its two axes of symmetry. This paper presents an experimental study on rectangular DSTCs with a particular focus on the effect of the cross-sectional aspect ratio (i.e., the ratio of the breadth to the width of the rectangular cross section). The effect of the cross-sectional shape of the inner steel tube (i.e., both elliptical and rectangular inner steel tubes were used) and the effect of FRP tube thickness were also investigated experimentally. Experimental results show that a larger aspect ratio will have no negative effect on the confinement effect in rectangular DSTCs; a rectangular DSTC with a larger aspect ratio generally has a larger ultimate axial strain and a higher axial stress at the ultimate axial strain; rectangular DSTCs with an elliptical steel tube generally have better performance than corresponding specimens with a rectangular steel tube. An existing model, which was developed based on a model for rectangular FRP-confined concrete columns and a model for circular DSTCs, is verified using the test results of the present study. The model generally provides close predictions for the peak axial stress of the confined concrete but yields conservative predictions for the ultimate axial strain for rectangular DSTCs.

Effect of Loading Pattern on Performance of FRP-HSC-Steel Double Skin Tubular Columns

2014 ◽  
Vol 919-921 ◽  
pp. 83-87
Author(s):  
Butje Alfonsius Louk Fanggi ◽  
Togay Ozbakkaloglu
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Experimental Program ◽  
Compressive Behavior ◽  
Loading Pattern ◽  
Tubular Columns ◽  
Strength Enhancement ◽  
Main Emphasis ◽  
Double Skin ◽  
The University

This paper reports on part of an ongoing experimental program at the University of Adelaide on FRP-concrete-steel double-skin tubular columns (DSTCs). The main emphasis of the study reported in this paper was to investigate the influence of loading pattern on the axial compressive behavior of DSTCs. To this end, 12 hollow and concrete-filled DSTCs were manufactured and tested under monotonic or cyclic axial compression. All of the specimens were manufactured using high-strength concrete (HSC). The results of the experimental study indicate that that concrete in cyclically loaded hollow DSTCs exhibits slightly larger strength and strain enhancement ratios than concrete in companion monotonically loaded DSTCs. The results also indicate that concrete in filled DSTCs exhibit slightly larger strength enhancement ratios than and similar strain enhancement ratios to concrete in monotonically loaded DSTCs.

Experimental Study on Concrete-Filled Steel Tubular with External Octagon Steel Tube and Inner Circle PVC-U Pipe under Axial Compression

2011 ◽  
Vol 368-373 ◽  
pp. 511-514
Author(s):  
Wei Bin Yuan ◽  
Shi Long Ma
Keyword(s):  
Experimental Study ◽  
Numerical Analysis ◽  
Axial Load ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Cross Sectional ◽  
Tubular Columns ◽  
Cross Sectional Size ◽  
Double Skin ◽  
Core Concrete

An investigation of the octagon-shaped concrete-filled double skin steel tubular columns which used PVC-U pipe to replace the steel tube as inner tube was carried out. In order to study the performances and mechanisms of the components when suffered axial load, ultimate axial bearing capacities of 9 components were tested. The cross-sectional size of the outer steel tube and inner PVC-U pipe and length of the specimen was concerned by the nominal steel ratio and the hollow ratio and slenderness ratio, respectively. The external steel tube and core concrete appeared three and four types of destruction phenomenons, respectively, but the inner PVC-U pipe did not destroy. Finally, experimental results and numerical analysis results were comparied.

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