Title:
GFRP-Reinforced Concrete Columns Subjected to Seismic Loads
Author(s):
Shamim Sheikh and Zahra Kharal
Publication:
Symposium Paper
Volume:
326
Issue:
Appears on pages(s):
56.1-56.10
Keywords:
columns; concrete confinement; corrosion resistance; ductility; GFRP; seismic response; sustainable infrastructure
DOI:
10.14359/51711039
Date:
8/10/2018
Abstract:
Steel corrosion in reinforced concrete structures costs a significant amount of resources globally. Use of glass fibre-reinforcement polymers (GFRP) as reinforcement presents a feasible and cost-effective solution to build sustainable infrastructure. Despite many advantages of GFRP, design codes do not recommend its usage in compression, primarily due to a lack of experimental data. The goal of this research is to gain a better understanding of the behavior of GFRP as internal reinforcement especially in columns. The part of the program discussed in some detail in this paper involved testing of 20 full-scale GFRP- and steel-RC columns under simulated earthquake loads. The variables investigated included column shape, amount and spacing of transverse reinforcement and axial load.
A significant conclusion drawn from this research is that GFRP can not only can be used efficiently as primary lateral reinforcement in columns but also confines the column concrete core more effectively than steel. GFRP longitudinal bars were found to resist about 60% of their tensile capacity in compression, but their low elastic modulus elasticity reduced the column capacity and stiffness. GFRP-reinforced columns with appropriate design can be made to have excellent seismic resistance.
Related References:
1. NSERC, “Bridging the Gap, Composites Extend Infrastructure Life.” http://www.nserc-crsng.gc.ca/Media-Media/ImpactStory-ArticlesPercutant_eng.asp?ID=1047, 2012, June 2017.
2. Tobbi, H., Farghaly, A.S., and Benmokrane, B., “Concrete columns reinforced longitudinally and transversally with glass fiber-reinforced polymer bars,” ACI Struct. J., V. 109, No. 48, 2012, pp. 551–558.
3. Affifi, M.Z., Mohamed, M.H., and Benmokrane, B.,“Axial Capacity of Circular Concrete Columns Reinforced with GFRP Bars and Spirals,” J. Compos. Constr., 2013, doi: 10.1061/(ASCE)CC.1943-5614.0000438
4. Tobbi, H., Farghaly, A. S., and Benmokrane, B., “Behaviour of concentrically loaded fiber-reinforced polymer reinforced concrete columns with varying reinforcement types and ratios.” ACI Struct. J., V. 111, No. 33, 2014a, pp. 375–386.
5. De Luca, A., Matta, F., and Nanni, A., “Behavior of full-scale glass fiber-reinforced polymer reinforced concrete columns under axial load.” ACI Struct. J., V. 107, No. 5, 2010, pp. 589–596.
6. ACI (American Concrete Institute), “Guide for the design and construction of structural concrete reinforced with fiber-reinforced polymer (FRP) bars.” ACI 440.1R-15, 2015, Farmington Hills, MI.
7. CSA (Canadian Standards Association), “Design and construction of building components with fibrereinforced polymers.” CSA S806-12, 2012, Rexdale, ON, Canada, 177.
8. CSA (Canadian Standards Association), “Canadian Highway Bridge Design Code.” CAN/CSA-S6-14, 2014, Rexdale, Ontario, Canada, 788.
9. Tavassoli, A, Liu, J, Sheikh, SA., “Glass Fiber-Reinforced Polymer-Reinforced Circular Columns under Simulated Seismic Loads,” ACI Structural Journal, V. 112, No. 1, Jan-Feb, 2015, 103-114.
10. Tavassoli, A., and Sheikh, S.A., “Seismic Resistance of Circular Columns Reinforced with Steel and GFRP.” ASCE Journal of Composites for Construction, Jan. 23, 2017. doi: 10.1061/(ASCE) CC.1943-5614.0000774
11. Kharal, Z. (2018), “Seismic Response of Square Columns Confined with GFRP Rectilinear Ties.” PhD Thesis, University of Toronto, Toronto.
12. ASTM, “Standard test method for compressive strength of cylindrical concrete specimens.” ASTM C39/C39M-17, 2017, West Conshohocken, PA.
13. Bae, S., “Seismic Performance of Full-Scale Reinforced Concrete Columns.” Ph.D. Thesis, University of Texas at Austin, USA, 2005, pp. 312.
14. Sheikh, S. A., and Khoury, S. S., “Confined concrete columns with stubs.” ACI Struct. J., V. 90, No. 4, 1993, pp. 414–431.