Creep and Shrinkage Deflections of RC Beams with Steel Fibers
Publication: Journal of Materials in Civil Engineering
Volume 6, Issue 4
Abstract
In this paper, two analytical approaches based on the effective modulus method (EMM) and the age‐adjusted effective modulus method (AEMM), are proposed for the prediction of deflections due to creep and shrinkage in reinforced‐concrete beams with a steel‐fiber concrete matrix under sustained loads. In the EMM‐based approach, the deflection due to creep is evaluated from an elastic analysis using a modulus of elasticity that accounts for the reduced creep coefficient in steel‐fiber concrete, while the deflection due to shrinkage is analyzed using the equivalent tensile‐force method, which accounts for the reduced shrinkage strains in the steel‐fiber concrete. The AEMM‐based approach considers the aging of steel‐fiber concrete and involves a simultaneous linear‐elastic analysis for deflections due to creep and shrinkage using an age‐adjusted effective modulus of elasticity. Tests on 12 SFRC beams as well as on the material properties were carried out. The proposed methods, using creep coefficients and shrinkage strains obtained from compressive creep test and free‐shrinkage test on steel‐fiber concrete, respectively, are found to predict the creep and shrinkage deflections with very good accuracy.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
“Annual book of ASTM standards, section 4: construction.” (1990). Vol. 4.02: Concrete and Aggregates, ASTM, Philadelphia, Pa.
2.
Balaguru, P. N., and Ramakrishnan, V. (1988). “Properties of fiber reinforced concrete: workability, behavior under long‐term loading, and air‐void characteristics.” ACI Mat. J., 85(3), 189–196.
3.
Balaguru, P. N., and Shah, S. P. (1992). “Fiber‐reinforced cement composites.” McGraw‐Hill Book Co., New York, N.Y., 449–492.
4.
Bažant, Z. P. (1972). “Prediction of concrete creep effects using age‐adjusted effective modulus method.” J. Am. Concrete Inst., 69(4), 212–217.
5.
Bažant, Z. P., and Kim, S. S. (1979). “Approximate relaxation function for concrete.” J. Struct. Div., ASCE, 105(12), 2695–2705.
6.
Chern, J. C., and Young, C. H. (1989). “Compressive creep and shrinkage of steel fiber reinforced concrete.” Int. J. Cement Composites and Lightweight Concrete, 11(4), 205–214.
7.
Chern, J. C., and Young, C. H. (1990). “Study of factors influencing drying shrinkage of steel fiber reinforced concrete.” ACI Mat. J., 87(2), 123–129.
8.
“Deflections of reinforced concrete flexural members.” (1990). ACI435.2R‐66, Manual of Concrete Practice, Am. Concrete Inst., Detroit, Mich., 435.2R‐1–435.2R‐29.
9.
“Design considerations for steel fiber reinforced concrete.” (1988). ACI 544.4R., ACI Struct. J., 85(5), 563–580.
10.
Hannant, D. J. (1978). “Fibre cements and fibre concrete.” John Wiley & Sons Ltd., New York, N.Y.
11.
Lim, T. Y., Paramasivam, P., and Lee, S. L. (1987). “Bending behavior of steel fiber concrete beams.” ACI Struct. J., 84(6), 524–536.
12.
Mangat, P. S., and Azari, M. M. (1986). “Compression creep behaviour of steel fiber reinforced cement composites.” Mat. and Struct., 19(113), 361–370.
13.
Mangat, P. S., and Azari, M. M. (1988). “Shrinkage of steel fiber reinforced cement composites.” Mat. and Struct. (RILEM), 21, 163–171.
14.
McHenry, D. (1943). “A new aspect of creep in concrete and its application to design.” Proc., Am. Soc. for Testing Mat., Vol. 43, 1069–1086.
15.
Neville, A. M., Dilger, W. H., and Brooks, J. J. (1983). “Creep of plain and structural concrete.” Construction Press, Longman Inc., New York, N.Y.
16.
“Prediction of creep, shrinkage, and temperature effects in concrete structures.” (1990). ACI 209R‐82, Manual of Concrete Practice, Am. Concrete Inst., Detroit, Mich., 209R‐1–209R‐92.
17.
“Structural use of concrete, part 1: code of practice for design and construction (BS 8110: part 1, 1985.” (1985). British Standards Institution, London, England.
18.
Swamy, R. N. (1980). “Prospects of fibre reinforcement in structural applications.” Proc., Symp. on Adv. in Cement Matrix Composites, Material Research Society, Boston, Mass., 159–169.
19.
Swamy, R. N., and Theodorakopoulos, D. D. (1979). “Flexural creep behavior of fiber reinforced cement composites.” Int. J. Cement Composites, 1(1), 37–49.
20.
Tan, K. H., Paramasivam, P., and Tan, K. C. (1993). “Long‐term deflections of steel fibre reinforced concrete beams.” 18th Conf., Our World in Concrete & Struct., Singapore, 255–262.
21.
Tan, K. H., Paramasivam, P., and Tan, K. C. (1994). “Instantaneous and long‐term deflections of steel fibre reinforced concrete beams.” ACI Struct. J., 91(4).
22.
Yu, W. W., and Winter, G. (1960). “Instantaneous and long‐time deflections of reinforced concrete beams under working loads.” ACI J., 57(1), 29–50.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 6 • Issue 4 • November 1994
Pages: 474 - 494
Copyright
Copyright © 1994 American Society of Civil Engineers.
History
Received: Dec 9, 1993
Published online: Nov 1, 1994
Published in print: Nov 1994
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.