Compressive behavior of hollow concrete columns reinforced with GFRP bars
PhD Thesis
Title | Compressive behavior of hollow concrete columns reinforced with GFRP bars |
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Type | PhD Thesis |
Authors | |
Author | Alajarmeh, Omar Saleh Awad |
Supervisor | Manalo, Allan |
Karunasena | |
Karu | |
Institution of Origin | University of Southern Queensland |
Qualification Name | Doctor of Philosophy |
Number of Pages | 111 |
Year | 2020 |
Digital Object Identifier (DOI) | https://doi.org/10.26192/21yk-ne68 |
Abstract | Hollow concrete columns (HCCs) reinforced with steel bars have been employed extensively for bridge piers, ground piles, and utility poles because they offer higher Firstly, HCCs with different inner-to-outer diameter (i/o) ratios was investigated by testing four concrete columns 250 mm in external diameter and reinforced longitudinally with six 15.9 mm diameter GFRP bars with different inner diameters (0, 40, 65, and 90 mm). One HCC reinforced with steel bars was also prepared and tested as a control sample. Based on the experimental results, increasing the i/o ratio up to 0.36 changed the failure behavior from brittle to ductile. GFRP-reinforced HCCs exhibited higher deformation capacity and confinement efficiency compared to the GFRP-reinforced SCC and steel-reinforced HCC. The optimal (i/o) ratio was found at 0.36 as it resulted in the highest confined strength and ductility for GFRP-reinforced HCC. Similarly, reinforcing with longitudinal GFRP bars enhanced the overall behavior of HCCs. The effect of varying the reinforcement ratio was investigated as the second study. To study this parameter, six HCCs reinforced longitudinally with GFRP bars The effect of spiral spacing and concrete compressive strength was investigated as the third study. Seven large-scale HCCs with (i/o) ratio of 0.36, and reinforced with six longitudinal GFRP bars were prepared and tested. Out of these seven columns, three had spiral spacing of 50 mm, 100 mm, and 150 mm, and one had no spirals to investigate the effect of this design parameter. The fc of the other three columns were varied from 21 to 44 MPa to investigate the effect of the concrete compressive strength. Test results show that reducing the spiral spacing resulted in increasing the design load capacity, ductility, and confined strength of the HCCs due to the high lateral confinement. Increasing fc, on the other hand, increased the axial load capacity and reduced the ductility and confinement efficiency due to the brittle behavior of the high concrete compressive strength. The analytical model was then developed considering the contribution of the GFRP bars and the confined concrete core, which accurately predicted the post-loading behavior of the HCCs. The experimental results from the three experimental studies demonstrated that the (i/o) ratio, p, pv , and fc affect the overall behavior of GFRP-reinforced HCCs. Therefore, a new design-oriented model considering the effects of these design parameters was developed in the fourth study to accurately and reliably describe the From the results of this research, a detailed understanding on how the critical design parameters affect the structural performance of GFRP-reinforced HCCs was gained. Moreover, the results from this research will provide useful information in revealing the many benefits of this new structurally efficient and non-corrosive construction system, which support the work of the technical committees engaged in the development of design provisions for GFRP-reinforced concrete columns. |
Keywords | compression, concrete, hollow columns, GFRP reinforcements, confinement, empirical modelling |
ANZSRC Field of Research 2020 | 400510. Structural engineering |
401602. Composite and hybrid materials | |
Byline Affiliations | School of Civil Engineering and Surveying |
https://research.usq.edu.au/item/q5z12/compressive-behavior-of-hollow-concrete-columns-reinforced-with-gfrp-bars
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COMPRESSIVE BEHAVIOR OF HOLLOW CONCRETE COLUMNS REINFORCED WITH GFRP BARS (Omar Alajarmeh).pdf | ||
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