Comparative evaluation of the axial behaviour of circular and square hollow concrete columns reinforced with GFRP bars

Heslin, Terry (2018) Comparative evaluation of the axial behaviour of circular and square hollow concrete columns reinforced with GFRP bars. [USQ Project]


Steel reinforcement has been used to strengthen concrete structures since the 19th century however corrosion has always provided long term issues for the durability of a structure. Fibre reinforced polymer (FRP) materials have been researched excessively in the hopes to provide an alternative to steel which is resistant to corrosion. Success has been reported in a number of papers, currently showing FRP bars performing well in structural elements when comparing to steel, with exception to columns. Current standards governing the use of FRP reinforcement state to ignore their contribution to the strength of compressive members.

The goal of this research was to develop an understanding as to how the cross-sectional geometry of a column reinforced with GFRP bar effects its axial behaviour. To achieve this goal, an experimental program was developed and the results were compared. The literature review was utilized to support these results and report conclusions.

The experimental program consisted of four columns, each casted using a different geometric section (a solid and hollow square column and a solid and hollow circular column). Each column was fabricated using the same reinforcement detail and concrete strength, and the cross-sectional area between square and circular columns was matched. The columns were then subject to compressive axial loading to failure and the results were obtained.

Behavioural data was collect in the form of failure behaviour, load deformation, and concrete, longitudinal, and spiral bar strain. This was presented throughout the results chapter and crucial observations were recorded. These were then addressed in the discussion chapter and conclusions were made in the following chapter.

This dissertation found that geometry of a column did not have a significant effect on the stiffness however effected almost all other parameters. The failure behaviour, capacity, and strain development were each effected by the shape of the column (circular or square) while the capacity, strain development, ductility, and confinement were each effected by the presence of a hollow section.

Theoretical evaluations also supported current papers which oppose the standards and suggest FRP bar does contribute the strength of a column. This can be seen from the 1% error shown by the code considering FRP in comparison to the 17% error shown by the code which currently ignores the contribution of FRP bar.

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Item Type: USQ Project
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021)
Supervisors: Manalo, Allan; Alajarmeh, Omar
Qualification: Bachelor of Engineering (Honours) (Civil)
Date Deposited: 31 Aug 2022 04:06
Last Modified: 29 Jun 2023 01:41
Uncontrolled Keywords: Steel reinforcement; corrosion; Fibre reinforced polymer (FRP)

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