Shear Strength of Normal Strength Concrete Beams Reinforced with Deformed GFRP Bars
Publication: Journal of Composites for Construction
Volume 5, Issue 4
Abstract
This paper evaluates the shear strength, Vc, of intermediate length (2.5 < a/d < 6) simply supported concrete beams subjected to four-point monotonic loading and reinforced with deformed, glass fiber-reinforced polymer (GFRP) reinforcement bars. Six different overreinforced GFRP designs, ρ > ρb, were tested with three replicate beams per design. All samples failed as a result of diagonal-tension shear. Measured shear strengths at failure are compared with theoretical predictions calculated according to traditional steel-reinforced concrete procedures and recently published expressions intended for beams reinforced with GFRP. Recommendations are made regarding the adequacy of shear strength prediction equations for GFRP-reinforced members. The study concludes that shear capacity is significantly overestimated by the “Building Code Requirements for Structural Concrete and Commentary” (ACI 318-99) expression for, Vc, as a result of the large crack widths, small compression block, and reduced dowel action in GFRP-reinforced flexural members. Shear strength was found to be independent of the amount of longitudinal GFRP reinforcement. A simplified empirical equation for predicting the ultimate shear strength of concrete beams reinforced with GFRP is endorsed.
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References
1.
Acharya, D. N., and Kemp, K. O. ( 1968). “Significance of dowel forces on the shear failure of rectangular reinforced concrete beams without web reinforcement.” ACI J., (10), 1265–1278.
2.
Ahmad, S. H., Khaloo, A. R., and Poveda, A. ( 1986). “Shear capacity of reinforced high-strength concrete beams.” ACI J., 297–305.
3.
ASCE-ACI Committee 426. (1973). “The shear strength of reinforced concrete members.”J. Struct. Engrg., ASCE, 99(6), 1091–1187.
4.
ASCE-ACI Committee 426. ( 1977). “Suggested revisions to shear provisions for building codes.” ACI J., 75(9), 458–469.
5.
ASCE-ACI Committee 445. (1998). “Recent approaches to shear design of structural concrete.”J. Struct. Engrg., ASCE, 124(12), 1375–1417.
6.
ASTM. ( 1994). “C496-94 standard test method for static modulus of elasticity and Poisson's ratio of concrete in compression.” ASTM C469-94, West Conshohocken, Pa.
7.
ASTM. ( 1996). “C496-96 standard test method for splitting tensile strength of cylindrical concrete specimens.” ASTM C496-96, West Conshohocken, Pa.
8.
ASTM. ( 1998). “C31/C31M-98 standard practice for making and curing concrete test specimens in the field.” ASTM C31-98, West Conshohocken, Pa.
9.
ASTM. ( 1999). “C39/C39M-99 standard test method for compressive strength of cylindrical concrete specimens.” ASTM C39-99, West Conshohocken, Pa.
10.
Babaei, K., and Hawkins, N. M. ( 1988). “Evaluation of bridge deck protective strategies.” ACI Concrete Int., 56–66.
11.
American Concrete Institute (ACI). ( 1999). “Building code requirements for structural concrete and commentary.” ACI 318-99 and ACI-318R-99, Detroit.
12.
Deitz, D. H., Harik, I. E., and Gesund, H. ( 1999). “One-way slabs reinforced with glass fiber reinforced polymer reinforcing bars.” ACI Proc., 4th Int. Symp., ACI, Detroit, 279–286.
13.
Ferguson, P. M., Breen, J. B., and Jirsa, J. O. ( 1988). Reinforced concrete fundamentals, 5th Ed., Wiley, New York.
14.
Goodspeed, C., Schmeckpeper, E., Henry, R., Yost, J. R., and Gross, T. ( 1990). “Fiber reinforced plastic grids for the structural reinforcement of concrete.” Proc., 1st Materials Engrg. Cong., ASCE, New York, 593–604.
15.
Grieef, S. ( 1996). “ISOROD GFRP dowel bars in concrete pavements,” MS thesis, Dept. of Civ. and Geological Engr., Univ. of Manitoba, Canada.
16.
Hughes Brothers, Inc. ( 1997). “Glass fiber reinforced polymer rebar.” Product Brochure, Seward, Neb.
17.
Krefeld, W. J., and Thurston, C. W. ( 1966). “Contribution of longitudinal steel to shear resistance of reinforced concrete beams.” ACI J., 63(3), 325–344.
18.
MacGregor, J. G. ( 1997). Reinforced concrete mechanics and design, 3rd Ed., Prentice-Hall, Upper Saddle River, N.J.
19.
Michaluk, C. R., Rizkalla, S., Tadros, G., and Benmokrane, B. ( 1998). “Flexural behavior of one-way concrete slabs reinforced by fiber reinforced plastic reinforcements.” ACI Structures J., 95(3), 353–364.
20.
Nagasaka, T., Fukuyama, H., and Tanigaka, M. ( 1993). “Shear performance of concrete beams reinforced with FRP stirrups.” ACI fiber-reinforced plastic reinforcement for concrete structures, SP-138, 789–811.
21.
Nanni, A. (1993). “Flexural behavior and design of RC Members using FRP Reinforcement.”J. Struct. Engrg., ASCE, 119(11), 3344–3359.
22.
Rajagopalan, K. S., and Ferguson, P. M. ( 1968). “Exploratory shear tests emphasizing percentage of longitudinal steel.” ACI J., 65-46, 634–638.
23.
Rebeiz, K. S. (1999). “Shear strength prediction for concrete members.”J. Struct. Engrg., ASCE, 125(3), 301–308.
24.
Sonobe, Y., et al. (1997). “Design guidelines of FRP reinforced concrete building structures.”J. Compos. for Constr., ASCE, 1(3), 90–115.
25.
Yost, J. R. ( 1993). “Fiber reinforced plastic grids for the structural reinforcement of concrete beams.” PhD dissertation, University of New Hampshire, Durham, N.H.
26.
Zsutty, T. ( 1971). “Shear strength for separate categories of simple beam tests.” ACI J., 138–143.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 5 • Issue 4 • November 2001
Pages: 268 - 275
History
Received: Aug 18, 2000
Published online: Nov 1, 2001
Published in print: Nov 2001
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