Effect of concrete wet packing density on the uni‐axial strength of manufactured sand CFST columns

2022 ◽  
Author(s):  
Mianheng Lai ◽  
Kaijie Wu ◽  
Xiaoling Ou ◽  
Mengru Zeng ◽  
Chengwei Li ◽  
...  
2020 ◽  
Vol 14 (54) ◽  
pp. 317-324
Author(s):  
Ali Golsoorat Pahlaviani ◽  
Ali Mohammad Rousta ◽  
Peyman Beiranvand

Concrete-filled steel tube (CFST) columns are increasingly used in the construction of high-rise buildings which require high strength and large working space especially at lower stories. As compared to reinforced concrete columns, existence of the exterior steel tube not only bears a portion of axial load but also most importantly provides confinement to the infill concrete.with the confinement provided by the steel tube, axial strength of the infill concrete can be largely enhanced.this paper presents the investigation effect of impact load on concrete-filled steel tube columns under fire by numerical simulations using ABAQUS software.the results indicate that the CFST sections with larger confinement factor ξ=1.23 behaved in a very ductile manner under lateral impact. And the sections with smaller confinement factor ξ=0.44  generally behaved in a brittle mechanism.


2021 ◽  
Author(s):  
Katie Chu

This research concentrates on the axial load behaviour of circular, square and rectangular concrete filled steel tube (CFST) columns incorporating high-performance self-consolidating concretes such as ultra-high strength concrete (UHSC), engineered cementitious composite (ECC), lightweight concrete (LWC), and crumb rubber concrete (CRC). Seventy-four CFST specimens with varying slenderness, shape, concrete type and presence of internal bar reinforcements are tested experimentally under axial compression loading. The effect of these variables on axial load-deformation response, strain characteristics, failure modes, concrete confinement and axial strength are evaluated through experimental results. Performance of existing analytical/code based models for axial strength and concrete confined strength is evaluated. Concretes without coarse aggregates including UHSC proved less effective at enhancing axial strength of filled tube columns through confinement. In contrast, confinement in filled steel tube columns was found most effective with the use of concretes with coarse aggregates such as LWC and CRC.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Jun Deng ◽  
Yifeng Zheng ◽  
Yi Wang ◽  
Tonghua Liu ◽  
Hui Li

Concrete-filled steel tubular (CFST) columns have been widely used for constructions in recent decades because of their high axial strength. In CFSTs, however, steel tubes are susceptible to degradation due to corrosion, which results in the decrease of axial strength of CFSTs. To further improve the axial strength of CFST columns, carbon fiber reinforced polymer (CFRP) sheets and basalt fiber reinforced polymer (BFRP) sheets are applied to warp the CFSTs. This paper presents an experimental study on the axial compressive capacity of CFRP-confined CFSTs and BFRP-confined CFSTs, which verified the analytical model with considering the effect of concrete self-stressing. CFSTs wrapped with FRP exhibited a higher ductile behavior. Wrapping with CFRP and BFRP improves the axial compressive capacity of CFSTs by 61.4% and 17.7%, respectively. Compared with the previous composite structural systems of concrete-filled FRP tubes (CFFTs) and double-skin tubular columns (DSTCs), FRP-confined CFSTs were convenient in reinforcing existing structures because of softness of the FRP sheets. Moreover, axial compressive capacity of CFSTs wrapped with CFRP sheets was higher than CFFTs and DSTCs, while the compressive strength of DSTCs was higher than the retrofitted CFSTs.


2018 ◽  
Vol 162 ◽  
pp. 04002
Author(s):  
Asraa Al-Goody ◽  
Esra Mete Güneyisi ◽  
Süleyman İpek

The Concrete Filled Steel Tubular (CFST) columns have several benefits in comparison to the ordinary steel or reinforced concrete ones. Therefore, they have become more commonly acknowledged in the structural applications. In this study, two design codes such as American Concrete Institute (ACI) and Eurocode 4 (EC4) were used for predicting the ultimate axial strength of CFST columns filled with self-compacting concrete (SCC). To evaluate the results, circular steel tube with different diameter to thickness (D/t) ratio of 30, 60, and 90 and steel yielding strength of 185, 275, and 450 MPa were considered as prediction parameters. The wall thickness and length to diameter (L/D) ratio of the steel tubes were kept constant. As an infill material for the steel tubes, 16 different SCC mixtures reported in the literature were studied and their compressive strength results were used to get the code predicted ultimate axial strength of the composite columns. The analysis of the results based on ACI and EC4 were performed and discussed comparatively.


2020 ◽  
Vol 168 ◽  
pp. 105979 ◽  
Author(s):  
Chang Yang ◽  
Pan Gao ◽  
Xingxiang Wu ◽  
Y. Frank Chen ◽  
Qi Li ◽  
...  

2014 ◽  
pp. 139-150
Author(s):  
Hai-Yang Wang ◽  
◽  
Xiao-Xiong Zha ◽  
Keyword(s):  

2021 ◽  
Author(s):  
Katie Chu

This research concentrates on the axial load behaviour of circular, square and rectangular concrete filled steel tube (CFST) columns incorporating high-performance self-consolidating concretes such as ultra-high strength concrete (UHSC), engineered cementitious composite (ECC), lightweight concrete (LWC), and crumb rubber concrete (CRC). Seventy-four CFST specimens with varying slenderness, shape, concrete type and presence of internal bar reinforcements are tested experimentally under axial compression loading. The effect of these variables on axial load-deformation response, strain characteristics, failure modes, concrete confinement and axial strength are evaluated through experimental results. Performance of existing analytical/code based models for axial strength and concrete confined strength is evaluated. Concretes without coarse aggregates including UHSC proved less effective at enhancing axial strength of filled tube columns through confinement. In contrast, confinement in filled steel tube columns was found most effective with the use of concretes with coarse aggregates such as LWC and CRC.


2021 ◽  
Vol 6 (5) ◽  
pp. 66
Author(s):  
Khandaker M. A. Hossain ◽  
Katie Chu ◽  
Muhammed S. Anwar

This paper presents the behavior of concrete-filled steel tube (CFST) columns infilled with fiber-reinforced self-consolidating ultrahigh strength concrete (UHSC) subjected to axial concentric monotonic loading to failure. UHSC is expected to improve ease of fabrication, strength, and ductility of CFST columns. Seventeen columns having varying geometric properties such as tube wall thickness, cross-sectional shape (circular, rectangular, and square), and slenderness were constructed and tested by applying load through both steel tube and concrete core. Circular columns were further distinguished by the presence or absence of main and hoop steel reinforcing bars in the core concrete. Axial load-displacement response, axial/transverse strain development, and failure modes were recorded during the loading history to analyze the performance. Experimental confined concrete strength and axial strength of UHSC-filled CFST columns were compared with those obtained from three suggested analytical models and three code-based design procedures including Eurocode 4, Canadian CAN/CSA S16, and American AISC. Analytical models were found to over-predict the confined concrete strength and the axial strength of CFST columns. Canadian and American codes were found to be most applicable for predicting axial strength of UHSC-filled CFST columns while remaining conservative.


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