Influence of a Longitudinal Circular Hole on Flexural Strength of Reinforced Concrete Beams
Publication: Practice Periodical on Structural Design and Construction
Volume 22, Issue 2
Abstract
The main aim of this investigation was to study the flexural strength of simply supported rectangular RC hollow beams (with a longitudinal circular hole) subjected to gradually increased and symmetrically applied two-point loads. Each hollow beam had a 25-, 40-, or 50-mm-diameter hole, and the position of the center of the hole also varied from 45 to 180 mm from the top. The cross section of the beam, the amount of longitudinal steel, and the transverse steel of the beam were kept constant. The same M20 grade of concrete was adopted for all of the beams. The shear span-to-effective depth ratio (av/d) of 2.69 was kept constant. Theoretical equations are developed, or existing equations are modified, to determine the first cracking load and the ultimate load of the beams. The influence of the hole on the strength of the beams is studied by taking into account the area and position of the hole. To examine the validity of the developed theoretical equation, 12 hollow RC beams and one solid RC beam were cast and tested to failure. The behavior and flexural strength of these hollow beams were compared with that of a solid RC beam that had the same outer dimensions and steel reinforcements. The flexural mode of failure was observed in all hollow RC beams tested. A comparison of experimental results shows that the developed theoretical model satisfactorily predicts the first cracking load and the ultimate flexural strength of hollow RC beams.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The test program of this paper was carried out at the Concrete and Structural Engineering Research Laboratory, Department of Civil Engineering, Bannari Amman Institute of Technology, Sathyamangalam, India. The authors thank all the staff members of the Civil Engineering Department and technicians of the laboratory for their helpful assistance in the preparation and testing of beams.
References
Abdalla, H., and Kennedy, J. B. (1995). “Design of prestressed concrete beams with openings.” J. Struct. Eng., 890–898.
Arun, M. (2015). Behavior and strength of reinforced concrete hollow beams: A thesis book for the degree of doctor of philosophy, Bannari Amman Institute of Technology, Sathyamangalam, Erode (DT), Tamilnadu, India.
Barney, G. B., Corley, W. G., Hanson, J. M., and Parmelee, R. A. (1977). “Behavior and design of prestressed concrete beams with large web openings.” PCI J., 22(6), 32–61.
Bower, J. E. (1966a). “Elastic stresses around holes in wide-flange beams.” J. Struct. Div., 92(2), 85–102.
Bower, J. E. (1966b). “Experimental stresses in wide-flange beams with holes.” J. Struct. Div., 92(5), 167–186.
Cho, S. H., and Redwood, R. G. (1992a). “Slab behavior in composite beams at opening, I: Analysis.” J. Struct. Eng., 2287–2303.
Cho, S. H., and Redwood, R. G. (1992b). “Slab behavior in composite beams at opening, II: Tests and verification.” J. Struct. Eng., 2304–2322.
Clawson, C., and Darwin, D. (1982a). “Tests of composite beams with web openings.” J. Struct. Div., 108(1), 145–162.
Clawson, C., and Darwin, D. (1982b). “Strength of composite beams at web openings.” J. Struct. Div., 108(3), 623–641.
Devdas, M., and Pillai, S. U. (2009). Reinforced concrete design, Tata McGraw-Hill, New Delhi, India.
Fahmy, E. H. (1988). Strength of composite beams with web openings, CSCE 1, Calgary, AB, Canada, 552–565.
Fahmy, E. H. (1996). “Analysis of composite beams with rectangular web openings.” J. Constr. Steel Res., 37(1), 47–62.
Fintel, M. (1986). Handbook of concrete engineering, Van Nostrand Reinhold Co., New York.
Heller, S. R. (1951). “Reinforced circular holes in bending with shear.” Ph.D. dissertation, Massachusetts Institute of Technology, Cambridge, MA.
James, G. M. (1997). Reinforced concrete mechanics and design, Prentice Hall, Upper Saddle River, NJ.
Mansur, M. A. (1998). “Effect of openings on the behaviour and strength of R/C beams in shear.” Cem. Concr. Compos., 20(6), 477–486.
Mansur, M. A. (1999). “Design of reinforced concrete beams with small openings under combined loading.” ACI Struct. J., 96(5), 675–682.
Mansur, M. A., and Hasnat, A. (1979). “Concrete beams with small openings under torsion.” J. Struct. Eng., 105(11), 2433–2447.
Mansur, M. A., and Tan, K. H. (1999). Concrete beams with openings: Analysis and design, CRC, New York.
McCormac, J. C., and Brown, R. H. (2014). Design of reinforced concrete. Wiley & Sons, New York.
Prentzas, E. G. (1968). “Behavior and reinforcement of concrete beams with large rectangular apertures.” Ph.D. thesis, Univ. of Sheffield, Sheffield, U.K.
Redwood, R., and Cho, S. H. (1992). “Design of steel and composite beams with web openings.” J. Constr. Steel Res., 25(1–2), 23–41.
Salam, S. A. (1977). “Beams with openings under different stress conditions,” Proc., 3rd Conf. on Our World in Concrete and Structures, CI-Premier, Singapore, 259–267.
Santhakumar, A. R. (2015). Concrete technology, S. Chand & Co., New Delhi, India.
Savin, G. N. (1951). Stress concentration around holes, Pergamon, New York.
Shetty, M. S. (2015). Concrete technology theory and practice, S. Chand & Co., New Delhi, India.
Somes, N. F., and Corley, W. G. (1974). Circular openings in webs of continuous beams’ shear in reinforced concrete, SP-42, American Concrete Institute, Detroit, 359–398.
Tan, K. H., Mansur, M. A., and Huang, L. M. (1996). “Reinforced concrete T-beams with large web openings in positive and negative moment regions.” ACI Struct. J., 93(3), 277–289.
Whitney, C. S. (1942). “Plastic theory of reinforced concrete design.” Trans. ASCE, 107, 251–326.
Information & Authors
Information
Published In
Practice Periodical on Structural Design and Construction
Volume 22 • Issue 2 • May 2017
Copyright
© 2016 American Society of Civil Engineers.
History
Received: May 1, 2016
Accepted: Aug 22, 2016
Published online: Oct 3, 2016
Discussion open until: Mar 3, 2017
Published in print: May 1, 2017
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.