Performance of concrete-filled double-skin circular tubes in compression
- Authors: Essopjee, Yoosuf
- Date: 2015
- Subjects: Prestressed concrete construction - Design and construction , Prestressed concrete construction - Testing , Reinforced concrete construction , Columns, Concrete , Tubes, Steel
- Language: English
- Type: Masters (Thesis)
- Identifier: http://ujcontent.uj.ac.za8080/10210/384770 , http://hdl.handle.net/10210/55708 , uj:16303
- Description: Abstract: CFDSCT columns are structural members that are filled with concrete and supported by circular steel tubes on the interior and exterior. These steel tubes serve as formwork and hence these members are economical and quicker to construct when compared to conventional concrete reinforced columns. They are also efficient because they take advantage of the high compressive strength of the concrete and high tensile strength of steel. Despite the fact that much research is ongoing internationally in the field of CFDSCTs, no experimental tests have been conducted on intermediate and slender CFDSCTs. Current research has been focused on short CFDSCT columns and varying amounts of confinement have been found in these tests. Design codes also do not cover CFDSCTs. In order to gain a more comprehensive understanding of the behaviour of CFSDSCTs, experimental tests were conducted on 32 concrete-filled double-skin circular tube (CFDSCT) columns. The CFDSCT columns were loaded in axial compression till failure. The parameters that were varied were the lengths and diameters of the outer steel tubes, and the strength of the outer steel tubes. The lengths ranged from 1 and 2.5 m, in half a metre increments. The CFDSCTs of one metre lengths, failed by yielding of the steel tubes. All the other CFDSCTs failed by overall buckling due to their large slenderness. Using the same philosophy as SANS 10162-1 and EC4, new formulas were developed to predict the results of the strengths of the CFDSCTs. The new formulas are in a similar format to SANS 10162-1 and EC4, and are 5% and 6% more conservative than the tests results, respectively. The ratio of the predicted results over the test results versus the slenderness was plotted and shows that the results were predicted fairly well. , M.Ing. (Civil Engineering)
- Full Text:
- Authors: Essopjee, Yoosuf
- Date: 2015
- Subjects: Prestressed concrete construction - Design and construction , Prestressed concrete construction - Testing , Reinforced concrete construction , Columns, Concrete , Tubes, Steel
- Language: English
- Type: Masters (Thesis)
- Identifier: http://ujcontent.uj.ac.za8080/10210/384770 , http://hdl.handle.net/10210/55708 , uj:16303
- Description: Abstract: CFDSCT columns are structural members that are filled with concrete and supported by circular steel tubes on the interior and exterior. These steel tubes serve as formwork and hence these members are economical and quicker to construct when compared to conventional concrete reinforced columns. They are also efficient because they take advantage of the high compressive strength of the concrete and high tensile strength of steel. Despite the fact that much research is ongoing internationally in the field of CFDSCTs, no experimental tests have been conducted on intermediate and slender CFDSCTs. Current research has been focused on short CFDSCT columns and varying amounts of confinement have been found in these tests. Design codes also do not cover CFDSCTs. In order to gain a more comprehensive understanding of the behaviour of CFSDSCTs, experimental tests were conducted on 32 concrete-filled double-skin circular tube (CFDSCT) columns. The CFDSCT columns were loaded in axial compression till failure. The parameters that were varied were the lengths and diameters of the outer steel tubes, and the strength of the outer steel tubes. The lengths ranged from 1 and 2.5 m, in half a metre increments. The CFDSCTs of one metre lengths, failed by yielding of the steel tubes. All the other CFDSCTs failed by overall buckling due to their large slenderness. Using the same philosophy as SANS 10162-1 and EC4, new formulas were developed to predict the results of the strengths of the CFDSCTs. The new formulas are in a similar format to SANS 10162-1 and EC4, and are 5% and 6% more conservative than the tests results, respectively. The ratio of the predicted results over the test results versus the slenderness was plotted and shows that the results were predicted fairly well. , M.Ing. (Civil Engineering)
- Full Text:
Concrete filled double skin circular tubes : a review
- Essopjee, Yoosuf, Dundu, Morgan
- Authors: Essopjee, Yoosuf , Dundu, Morgan
- Date: 2014
- Subjects: Prestressed concrete construction , Columns, Concrete , Plates, Iron and steel
- Type: Article
- Identifier: uj:5083 , ISBN 9781614994657 , ISBN 9781614994664 , http://hdl.handle.net/10210/13654
- Description: A review of the research conducted on the compressive strength of concrete filled double skin circular tubes (CFDSCT) columns is conducted. Variables of the CFDSCT considered in this review include the concrete strength, steel strength, inner and outer tube diameter, steel thickness and length of the stub columns. Test results show that the composite columns had compressive strengths of up to 41% higher than the sum of the individual strengths of the section. All the outer tubes of these composite columns by failed local buckling. A review of the design equations proposed are presented and discussed. The paper also identifies gaps for further research for these types of columns.
- Full Text:
- Authors: Essopjee, Yoosuf , Dundu, Morgan
- Date: 2014
- Subjects: Prestressed concrete construction , Columns, Concrete , Plates, Iron and steel
- Type: Article
- Identifier: uj:5083 , ISBN 9781614994657 , ISBN 9781614994664 , http://hdl.handle.net/10210/13654
- Description: A review of the research conducted on the compressive strength of concrete filled double skin circular tubes (CFDSCT) columns is conducted. Variables of the CFDSCT considered in this review include the concrete strength, steel strength, inner and outer tube diameter, steel thickness and length of the stub columns. Test results show that the composite columns had compressive strengths of up to 41% higher than the sum of the individual strengths of the section. All the outer tubes of these composite columns by failed local buckling. A review of the design equations proposed are presented and discussed. The paper also identifies gaps for further research for these types of columns.
- Full Text:
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