Krishna, Tanniru Vamshi (2017) Investigation of shear behaviour of geopolymer concrete beams reinforced with spiral GFRP ligatures. Coursework Masters thesis, University of Southern Queensland. (Unpublished)
Abstract
The corrosion has become the costly problem for the steel reinforced structures in worse weather conditions. Stirrups are the outermost reinforcement which exposes to the corrosion at first. The Fiber reinforced polymer (FRP) composite bars has gained considerable worldwide interest as internal reinforcement to concrete structures that operate in highly aggressive environments where corrosion of steel reinforcement is a major problem and contains many other advantages like high strength to weight ratio, High chemical resistance etcetera. Simultaneously, geopolymer cement has a widespread attention due to its eco friendly nature. The geopolymer concrete has very low rate of CO2 emission when compared with OPC.
Generally, in shear reinforcement of RC beams the traditional steel stirrups were using from long ago. Replacing the traditional individual transverse reinforcement with continuous spiral can reduce the labor cost for production of reinforcement cages. The spiral continuous stirrups were already proven to be effective replacement for the traditional stirrups in case of steel. However, there is no adequate researches done to prove the advantages of combined use of beams with FRP spiral stirrups with Geopolymer concrete. Hence, this study investigated the shear behavior of geopolymer concrete structure reinforced with GFRP spiral stirrups to check the suitability of this combination.
Five slender beams with a/d (shear span/depth ratio) 3.07 were prepared for this study which were distributed as three beams for study of the shear behavior of the geopolymer concrete beams reinforced with spiral ligature with different pitch, one beam was to find the shear capacity of geopolymer concrete which prepared with no stirrups and the last beam was prepared using traditional transverse FRP reinforcement to compare the behavior of spiral stirrups with traditional stirrups. The spacing of GFRP has a direct effect on strength and deflection of the beam which has increased the strength capacity and deflection of beams with the decrease in pitch spacing. The beams with 150,100 and 75 mm spacing were enhanced ultimate load taking capacity of beam by 140%, 195% and 220% increase respectively when compared with the load taking capacity of beam with no transverse reinforcement. The spiral continuous stirrups increased the load taking capacity of beams by 20% when compared with beam with traditional stirrups of same spacing. The failure modes of the beams evolved from shear tension to shear compression with increase of area of shear reinforcement. The stiffness of all the beams was similar at initial phase of loading but post cracking stiffness behavior was varied with the change of stirrup spacing. Where, the beams with 150mm spacing were failed shortly after decrease in their stiffness the beam with spiral 75 mm spacing withstand the loads after decreasing the stiffness also.
Modified equations available for concrete contribution of beams reinforced with FRP bars for shear and FRP spiral continuous stirrups contribution for shear were used to analyze the applicability of these equations to current study. Kara , Alam and hussien equations predicted the most accurate results with experimental to theoretical prediction ratio (Vc.test/Vc.pred) of 1.29 and 1.37 while ACI.1 R-06 equation available for shear contribution of spiral stirrups also predicted the reliable values with 1.15,1.38 and 0.89 experimental to theoretical prediction ratio (Vc.test/Vc.pred) respectively with stirrups spacing 150,100 and 75.
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| Item Type: | Thesis (Non-Research) (Coursework Masters) |
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| Item Status: | Live Archive |
| Additional Information: | Current UniSQ staff and students can request access to this thesis. Please email research.repository@unisq.edu.au with a subject line of SEAR thesis request and provide: Name of the thesis requested and Your name and UniSQ email address. |
| Faculty/School / Institute/Centre: | Current - Faculty of Health, Engineering and Sciences - No Department (1 Jul 2013 -) |
| Supervisors: | Manalo, Allan; Maranan, Ginghis |
| Qualification: | Master of Engineering Sciences (Structural Engineering) |
| Date Deposited: | 16 Jul 2026 03:55 |
| Last Modified: | 16 Jul 2026 03:55 |
| Uncontrolled Keywords: | shear, spiral continuous stirrups, glass fiber reinforced polymer (GFRP), geopolymer concrete. |
| URI: | https://sear.unisq.edu.au/id/eprint/53256 |
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