Shear behaviour of continuous concrete beams reinforced with GFRP bars
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Date
2015
Authors
Mahmoud, Karam Abdou Awad
Journal Title
Journal ISSN
Volume Title
Publisher
ASCE
ASCE
NRC Research press
ASCE
NRC Research press
Abstract
Continuous beams represent main structural elements in most reinforced concrete (RC) structures such as parking garages and overpass bridges. Deterioration of such structures due to corrosion of steel reinforcement is common in North America. To overcome the corrosion problems, the use of fiber-reinforced polymer (FRP) bars and stirrups becomes a viable alternative to steel reinforcement. However, to date, the shear behaviour of FRP-RC continuous beams has not been explored yet. As such, the objective of this study is to investigate the shear behaviour of such beams.
In this study, twenty four full-scale continuous concrete beams were constructed and tested. The test beams had rectangular cross section with 200-mm width and a height of 300, 550 or 850 mm and were continuous over two equal spans. The main investigated parameters were concrete strength, type and ratio of longitudinal reinforcement, type and ratio of transverse reinforcement and beam effective depth. Moreover, a 3-D nonlinear finite element model (FEM) was constructed to simulate the behaviour of FRP-RC continuous beams. The model was verified against the experimental results and validated against test results from previous studies. Then, the verified/validated model was used to conduct a parametric study to investigate the effect of a wide range of the parameters on the shear behaviour of GFRP-RC beams.
The experimental and FEM results showed that shear-critical GFRP-RC continuous beams exhibited moment redistribution. Also, it was observed that increasing the concrete strength and the longitudinal reinforcement ratio increased the shear strength significantly. Moreover, the presence of GFRP stirrups significantly enhanced the shear strength of the tested beams. Regarding the size effect, test results showed that there was adverse or no size effect on the shear strength of GFRP-RC continuous beams when they failed in the interior shear span while beams failed in the exterior shear span exhibited clear size effect. Furthermore, a comparison between the test results and the provisions of the available models and FRP standards and design guidelines in North America revealed that these design provisions can be safely applied to continuous beams.
Description
Keywords
Shear strength, Moment redistribution, Continuous beams, High strength concrete, GFRP bars, GFRP stirrups, Size effect
Citation
Mahmoud, K. and El-Salakawy, E. (2014). ”Shear Strength of GFRP-Reinforced Concrete Continuous Beams with Minimum Transverse Reinforcement.” J. Compos. Constr., 18(1), 04013018.
Mahmoud, K. and El-Salakawy, E. (2015). "Effect of Transverse Reinforcement Ratio on the Shear Strength of GFRP-RC Continuous Beams." J. Compos. Constr. , 10.1061/(ASCE)CC.1943-5614.0000583 , 04015023.
Mahmoud, K. and El-Salakawy, Ehab. 2015. Shear strength of GFRP-RC continuous beams without transverse reinforcement. Canadian Journal of Civil Engineering, 0, 0, 10.1139/cjce-2014-0238
Mahmoud, K. and El-Salakawy, E. (2015). "Effect of Transverse Reinforcement Ratio on the Shear Strength of GFRP-RC Continuous Beams." J. Compos. Constr. , 10.1061/(ASCE)CC.1943-5614.0000583 , 04015023.
Mahmoud, K. and El-Salakawy, Ehab. 2015. Shear strength of GFRP-RC continuous beams without transverse reinforcement. Canadian Journal of Civil Engineering, 0, 0, 10.1139/cjce-2014-0238