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.

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.

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.

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.

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.

FRP-Concrete-Steel Double Skin Tubular Cantilever Beams: Behavior under Cyclic Loading

2015 ◽  
Vol 752-753 ◽  
pp. 572-577
Author(s):  
Yunita Idris ◽  
Togay Ozbakkloglu
Keyword(s):  
Experimental Study ◽  
Cyclic Loading ◽  
Lateral Displacement ◽  
High Strength ◽  
Steel Tube ◽  
Flexural Behavior ◽  
Cantilever Beams ◽  
Test Results ◽  
Double Skin ◽  
Reversed Cyclic

This paper reports on an experimental study on the flexural behavior of fiber reinforced polymer (FRP)-concrete-steel double skin cantilever beams (referred to as DSTBs) that were tested under reversed cyclic loading. The beams were manufactured using a high-strength concrete (HSC) mix and they were 150 mm in diameter and 1.2 m in length. The main parameters of the experimental study included the size of the inner steel tube and the use of mechanical connectors in the form of steel rings welded on the inner steel tube. Test results indicate that DSTBs are capable of developing a highly ductile behavior under reversed cyclic lateral displacement excursions. It is found that the addition of mechanical connectors on the steel tube has no significant influence on the lateral displacement capacity of the test specimens, but they can eliminate the slippage between the concrete and inner steel tube. Examination of the test results has led to a number of significant conclusions on the influence of the beam parameters on the performance of DSTBs, which are discussed in the paper.

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.

scholarly journals Influence of steel tube thickness and concrete strength on the axial capacity of stub CFST columns

2018 ◽  
Author(s):  
Carmen Ibáñez Usach ◽  
David Hernández-Figueirido ◽  
Ana Piquer Vicent
Keyword(s):  
High Strength Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Steel Tube ◽  
Experimental Program ◽  
Ultimate Capacity ◽  
Strength Concrete ◽  
Axial Capacity ◽  
Thin Walled ◽  
Cfst Columns

In order to study the mechanical response of concrete-filled steel tubular (CFST) columns, several experimental and theoretical studies have been conducted in the last years. However, the influence of thin-walled steel tubes on the axial capacity of these composite columns is not completely stablished, especially when it is combined with high-strength concrete as infill. In this paper, the results of an experimental campaign on 9 concrete-filled steel tubular stub columns subjected to concentric load are presented. Different cross-section shapes are considered in this campaign, i.e. circular, square and rectangular. The influence of the steel tube wall thickness is analysed by including in the tests specimens with thin-walled tubes, whose behaviour needs to be studied in depth given the issues arising when working under compression. The experimental program is designed so the analysis of the results permits to drawn consistent conclusions. For each series, the steel tube thickness is the only geometric parameter modified in order to properly study its effect. Besides, two different concrete strengths were considered for the concrete infill, i.e. normal and high- strength concrete, to observe their effect on the ultimate capacity of the columns. During the tests, the specimens are subjected to axial load and the evolution of the axial displacement with the load is registered. The ultimate capacity of each specimen is obtained and an analysis of the steel tube thickness and concrete strength influence is accomplished. Finally, the study of the dependency of the failure mode on these parameters is carried out.

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.

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