Experimental Study on RC Walls with Opening Strengthened by Externally Bonded CFRP
Publication: Journal of Composites for Construction
Volume 23, Issue 2
Abstract
RC walls with an opening under eccentric axial loads exhibit cracks around the opening leading to a reduction in the ultimate strength of the wall. These cracks are mainly due to changes in the load path within the wall and stress concentration around the opening. Strengthening is usually required to enhance the ultimate strength of the wall, and carbon fiber–reinforced polymer (CFRP) is a suitable option for this purpose. In this paper, 18 one-third scaled RC walls with an opening were strengthened using seven distinct externally bonded (EB) CFRP layouts and were loaded up to failure under various support conditions. These walls were subjected to a uniformly distributed axial load with an eccentricity of one-sixth of the wall’s thickness. Crack patterns, failure modes, ultimate strength, and typical strain measurement of CFRP–concrete interface are presented and discussed in detail. The experimental outcomes revealed that the CFRP layout enhances the ultimate strength of RC walls by 14.0%–59.7% and 3.0%–40.8% for walls under one-way and two-way actions, respectively. The efficiency of each CFRP layout is also investigated to prioritize the appropriate layouts for each specific support condition.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors wish to acknowledge an in-kind contribution from SIKA Australia Pty. Ltd. by providing the CFRP material and epoxy. The authors also express their thanks to the concrete lab technicians at Griffith University, School of Engineering. The authors wish to acknowledge an in-kind contribution from Dr Mojtaba Ale-Mohamamdi for proofreading this paper.
References
ACI (American Concrete Institute). 2008. Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures. ACI 440. Farmington Hills, MI: ACI.
ACI (American Concrete Institute). 2014. Building code requirements for structural concrete and commentary. ACI 318. Farmington Hills, MI: ACI.
AS (Australian Standard). 2009. Concrete structures. AS3600. Sydney, Australia: Standards Association of Australia.
BBK 04 (Boverkets Handbok om Betongkonstruktioner). 2004. “The Swedish building administration’s handbook on concrete structures.” [In Swedish.] Stockholm, Sweden: Swedish Building Administration, Division of Buildings.
CEB-FIP (Comité Euro-International du Béton–Fédération international de la Précontrainte). 1993. CEB-FIP model code 90. London: Thomas Telford.
Concrete Society. 2012. Design guidance for strengthening concrete structures using fibre composite materials. Camberley, UK: Concrete Society.
Doh, J.-H., and S. Fragomeni. 2005. “Evaluation of experimental work on concrete walls in one and two-way action.” Aust. J. Struct. Eng. 6 (1): 37. https://doi.org/10.1080/13287982.2005.11464943.
Doh, J.-H., and S. Fragomeni. 2006. “Ultimate load formula for reinforced concrete wall panels with openings.” Adv. Struct. Eng. 9 (1): 103–115. https://doi.org/10.1260/136943306776232954.
Doh, J.-H., Y. Loo, and S. Fragomeni. 2010. “Concrete walls with and without openings supported on three sides.” In Incorporating sustainable practice in mechanics and structures of materials, 209–214. Boca Raton, FL: Taylor & Francis Group.
Enochsson, O., J. Lundqvist, B. Täljsten, P. Rusinowski, and T. Olofsson. 2007. “CFRP strengthened openings in two-way concrete slabs: An experimental and numerical study.” Constr. Build. Mater. 21 (4): 810–826. https://doi.org/10.1016/j.conbuildmat.2006.06.009.
fib (Fédération Internationale du Béton). 2001. Externally bonded FRP reinforcement for RC structures. fib Bulletin 14, fib Task Group 9.3. Lausanne, Switzerland: fib.
Fragomeni, S., J.-H. Doh, and D. Lee. 2012. “Behavior of axially loaded concrete wall panels with openings: An experimental study.” Adv. Struct. Eng. 15 (8): 1345–1358. https://doi.org/10.1260/1369-4332.15.8.1345.
Ho, N. M., J. H. Doh, and S. Fragomeni. 2017. “Instability analysis of reinforced concrete walls with various support conditions.” Struct. Des. Tall Special Build. 26 (7): e1353. https://doi.org/10.1002/tal.1353.
Ho, N. M., and J.-H. Doh. 2018. “Experimental and numerical investigations of axially loaded RC walls restrained on three sides.” Struct. Des. Tall Special Build. 27 (7): e1459. https://doi.org/10.1002/tal.1459.
JSCE (Japanese Society of Civil Engineers). 2000. Recommendations for upgrading of concrete structures with use of continuous fiber sheets. Tokyo: JSCE.
Lima, M. M., J.-H. Doh, M. N. S. Hadi, and D. Miller. 2016. “The effects of CFRP orientation on the strengthening of reinforced concrete structures.” Struct. Des. Tall Special Build. 25 (15): 759–784. https://doi.org/10.1002/tal.1282.
Mohammed, B., L. W. Ean, and M. A. Malek. 2013. “One way RC wall panels with openings strengthened with CFRP.” Constr. Build. Mater. 40 (16): 575–583. https://doi.org/10.1016/j.conbuildmat.2012.11.080.
Popescu, C., G. Sas, T. Blanksvärd, and B. Täljsten. 2015. “Concrete walls weakened by openings as compression members: A review.” Eng. Struct. 89 (16): 172–190. https://doi.org/10.1016/j.engstruct.2015.02.006.
Popescu, C., G. Sas, T. Blanksvärd, and B. Täljsten. 2016a. “Concrete walls with cutout openings strengthened by FRP confinement.” J. Compos. Constr. 21 (3): 04016106. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000759.
Popescu, C., G. Sas, C. Sabău, and T. Blanksvärd. 2016b. “Effect of cut-out openings on the axial strength of concrete walls.” J. Struct. Eng. 142 (11): 04016100. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001558.
Popescu, C., J. W. Schmidt, P. Goltermann, and G. Sas. 2017. “Assessment of RC walls with cut-out openings strengthened by FRP composites using a rigid-plastic approach.” Eng. Struct. 150: 585–598. https://doi.org/10.1016/j.engstruct.2017.07.069.
Sabau, C., C. Popescu, G. Sas, T. Blanksvärd, and B. Täljsten. 2016. “Monitoring structural behavior of reinforced concrete walls with openings using digital image correlation.” In Proc., 19th IABSE Congress, 1803–1811. Zürich, Switzerland: International Association for Bridge and Structural Engineering.
Saheb, S. M., and P. Desayi. 1989. “Ultimate strength of RC wall panels in one-way in-plane action.” J. Struct. Eng. 115 (10): 2617–2630. https://doi.org/10.1061/(ASCE)0733-9445(1989)115:10(2617).
Saheb, S. M., and P. Desayi. 1990. “Ultimate strength of RC wall panels with openings.” J. Struct. Eng. 116 (6): 1565–1577. https://doi.org/10.1061/(ASCE)0733-9445(1990)116:6(1565).
SIKA Australia Pty. Ltd. 2014. Sika product data sheet, SikaWrap-230 C. Brisbane, QLD, Australia: SIKA Australia Pty. Ltd.
Information & Authors
Information
Published In
Copyright
©2019 American Society of Civil Engineers.
History
Received: Oct 19, 2017
Accepted: Sep 7, 2018
Published online: Feb 8, 2019
Published in print: Apr 1, 2019
Discussion open until: Jul 8, 2019
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.