Effect of Concrete Compressive Strength on the Behaviour of GFRP Reinforced Hollow Concrete Columns

Oosthuizen, Alexandra L. (2018) Effect of Concrete Compressive Strength on the Behaviour of GFRP Reinforced Hollow Concrete Columns. [USQ Project]


Concrete structures in many parts of the world are exhibiting signs of severe degradation due to corrosion of steel reinforcement, especially those located in harsh environments such as tidal and marine environments. Due to the porous nature of concrete, it is difficult to adequately protect steel from corrosion and subsequent damage, especially in hollow structures where cover to reinforcement is limited. This has led to many structures requiring repair or replacement prematurely with respect to their design life. To mitigate against damage to concrete structures caused by corroding steel reinforcement, alternative, corrosion resistant reinforcement materials have been proposed to replace steel in newly designed concrete structures. Their use is expected to minimise the risk of structures requiring significant repairs during their design life. One such material is glass fibre reinforced polymer (GFRP) reinforcement.

This research investigates the use of GFRP bars and spirals as internal (longitudinal and transverse) reinforcement in hollow concrete columns. Hollow concrete columns have a number of benefits over their solid counterparts, including improved strength to mass ratio and improved seismic performance. As a critical design parameter, concrete compressive strength has a significant effect on the behaviour and capacity of concrete structures. This study therefore focuses specifically on the effect of concrete compressive strength on the behaviour of GFRP reinforced hollow concrete columns. This involved the experimental analysis of four hollow columns of 1m height, 250mm outer diameter and 90mm inner diameter, with concrete compressive strengths ranging from 21 to 44 MPa.

The results of this research indicate that an increase in concrete compressive strength (f’c ) in GFRP reinforced columns is associated with an increase in axial load capacity and stiffness. Conversely, increase in concrete compressive strength (f’c ) caused a decrease in ductility and confinement efficiency of the concrete columns. This is primarily due to the ii brittle nature of high strength concrete. Analysis of the experimental results demonstrates that the experimental columns have a higher load capacity than the existing theoretical model predicts. This indicates that GFRP longitudinal and transverse reinforcement contributes in a significant manner to the capacity of concrete columns and should be considered in theoretical models. A proposed model was found to more accurately describe the axial capacity of GFRP reinforced hollow concrete columns with an average error of 2%.

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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
Qualification: Bachelor of Engineering (Honours) (Civil)
Date Deposited: 06 Sep 2022 01:15
Last Modified: 29 Jun 2023 02:25
Uncontrolled Keywords: concrete structures; compressive strength; corrosion; steel reinforcement; GFRP bars
URI: https://sear.unisq.edu.au/id/eprint/40779

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