Title:
Size Effect on Ultimate Shear Strength of Steel Fiber- Reinforced Concrete Slender Beams
Author(s):
Shih-Ho Chao
Publication:
Structural Journal
Volume:
117
Issue:
1
Appears on pages(s):
145-158
Keywords:
shear strength; size effect; slender beam; steel fiber-reinforced concrete (SFRC)
DOI:
10.14359/51718018
Date:
1/1/2020
Abstract:
While the size effect on ultimate shear strength of plain concrete (PC) slender beams has been extensively researched in the past decades, limited tests have been carried out to study the extent and mechanism of size effect in steel fiber-reinforced concrete (SFRC) beams. ACI 318-19 restricts the use of steel fibers as the minimum shear reinforcement to beams with a height of up to 24 in. (610 mm). In this study, in addition to analyzing available testing data, an experimental study was carried out on a series of SFRC beams with a range of heights including 12, 18, 24, 36, and 48 in. (305, 457, 610, 915, and 1220 mm). A digital image correlation (DIC) technology with a full-field deformation measuring capability was used to identify the underlying factors that cause size effect on the ultimate shear strength of SFRC slender beams. The results are distinctive because they dispute the conventional hypothesis by correlating the size effect of the ultimate shear strength on SFRC beams to the effects of the compression zone and dowel resistance, rather than by simply lowering the aggregate interlock or fiber bridging capacity in larger SFRC beams due to a wider critical crack. Consequently, a less robust dowel zone such as one lacking well-distributed steel fibers or an inadequate fiber dosage can result in early failure of dowel resistance and subsequent shear failure, which intensifies the size effect.
Related References:
ACI Committee 318, 2019, “Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19),” American Concrete Institute, Farmington Hills, MI, 624 pp.
Ashour, S. A.; Hasanain, G. S.; and Wafa, F. F., 1992, “Shear Behavior of High-Strength Fiber Reinforced Concrete Beams,” ACI Structural Journal, V. 89, No. 2, Mar.-Apr., pp. 176-184.
ASTM A820/A820M-16, 2016, “Standard Specification for Steel Fibers for Fiber-Reinforced Concrete,” ASTM International, West Conshohocken, PA.
Bažant, Z. P., and Sun, H.-H., 1988, “Size Effect in Diagonal Shear Failure: Influence of Aggregate Size and Stirrups,” ACI Materials Journal, July-Aug., pp. 259-272.
Collins, M. P., and Kuchma, D., 1999, “How Safe Are Our Large, Lightly-Reinforced Concrete Beams, Slabs, and Footings?” ACI Structural Journal, V. 96, No. 4, July-Aug., pp. 482-490.
Collins, M. P., and Mitchell, D., 1997, Prestressed Concrete Structures, Response Publications, Canada, 766 pp.
Dinh, H. H., 2009, “Shear Behavior of Steel Fiber Reinforced Concrete Beams without Stirrup Reinforcement,” Doctoral Dissertation, Dept. of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI, 285 pp.
Dinh, H. H.; Parra-Montesinos, G. J.; and Wight, J. K., 2010, “Shear Behavior of Steel Fiber Reinforced Concrete Beams without Stirrup Reinforcement,” ACI Structural Journal, V. 107, No. 5, Sept.-Oct., pp. 597-606.
Ferguson, P. M.; Breen, J. E.; and Jirsa, J. O., 1988, Reinforced Concrete Fundamentals, fifth edition, John Wiley & Sons, Inc., New York, 768 pp.
Kani, G. N. J., 1967, “How Safe Are Our Large Reinforced Concrete Beams?” ACI Journal Proceedings, V. 64, No. 3, Mar., pp. 128-141.
Khaja, M. N., and Sherwood, E. G., 2013, “Does the Shear Strength of Reinforced Concrete Beams and Slabs Depend Upon the Flexural Reinforcement Ratio or the Reinforcement Strain?” Canadian Journal of Civil Engineering, V. 40, No. 11, pp. 1068-1081. doi: 10.1139/cjce-2012-0459
Kwak, Y.-K.; Eberhard, M. O.; Kim, W.-S.; and Kim, J., 2002, “Shear Strength of Steel Fiber-reinforced Concrete Beams without Stirrups,” ACI Structural Journal, V. 99, No. 4, July-Aug., pp. 530-538.
Leonhardt, F., and Walther, R., 1962, “The Stuttgart Shear Tests,” Translation of articles from Beton und Stahlbetonbau, 56(12), 1961, and 57(2,3,6,7,8), Cement and Concrete Association Library Translation No. 111, Wexham Springs, Dec. 1964, 134 pp.
Lubell, A.; Sherwood, T.; Bentz, E. C.; and Collins, M. P., 2004, “Safe Shear Design of Large, Wide Beams,” Concrete International, V. 26, No. 1, Jan., pp. 66-78.
Mansur, M. A.; Ong, K. C. G.; and Paramasivam, P., 1986, “Shear Strength of Fibrous Concrete Beams without Stirrups,” Journal of Structural Engineering, ASCE, V. 112, No. 9, pp. 2066-2079. doi: 10.1061/(ASCE)0733-9445(1986)112:9(2066)
Minelli, F.; Conforti, A.; Cuenca, E.; and Plizzari, G., 2014, “Are Steel Fibres Able to Mitigate or Eliminate Size Effect in Shear?” Materials and Structures, V. 47, No. 3, pp. 459-473. doi: 10.1617/s11527-013-0072-y
Muttoni, A., and Ruiz, M. F., 2008, “Shear Strength of Members without Transverse Reinforcement as Function of Critical Shear Crack Width,” ACI Structural Journal, V. 105, No. 2, Mar.-Apr., pp. 163-172.
Naaman, A. E., 2012, Prestressed Concrete—Analysis and Design, Fundamentals, third edition, Techno Press 3000, Ann Arbor, MI, 1176 pp.
Narayanan, R., and Darwish, I. Y. S., 1987, “Use of Steel Fibers as Shear Reinforcement,” ACI Structural Journal, V. 84, No. 3, May-June, pp. 216-227.
Park, R., and Paulay, T., 1975, Reinforced Concrete Structures, John Wiley & Sons, Inc., New York, 769 pp.
Parra-Montesinos, G. J., 2006, “Shear Strength of Beams with Deformed Steel Fibers,” Concrete International, V. 28, No. 11, Nov., pp. 57-66.
Sherwood, E. G., 2008, “One-Way Shear Behavior of Large, Lightly-Reinforced Concrete Beams and Slabs,” PhD dissertation, Department of Civil Engineering, University of Toronto, Toronto, ON, Canada, 547 pp.
Shioya, T., 1989, Shear Properties of Large Reinforced Concrete Member, Special Report of Institute of Technology, Shimizu Corporation, No. 25, 198 pp.
Shioya, T.; Iguro, M.; Nojiri, Y.; Akiyama, H.; and Okada, T., 1990, Shear Strength of Large Reinforced Concrete Beams’ Fracture Mechanics: Application to Concrete, SP-118, V. C. Li and Z. P. Bažant, eds., American Concrete Institute, Farmington Hills, MI, pp. 259-279.
Shoaib, A.; Lubell, A. S.; and Bindiganavile, V. S., 2014, “Size Effect in Shear for Steel Fiber-Reinforced Concrete Members without Stirrups,” ACI Structural Journal, V. 111, No. 5, Sept.-Oct., pp. 1081-1090. doi: 10.14359/51686813
Sneed, L. H., and Ramirez, J. A., 2010, “Influence of Effective Depth on Shear Strength of Concrete Beams Experimental Study,” ACI Structural Journal, V. 107, No. 5, Sept.-Oct., pp. 554-562.
Stratford, T., and Burgoyne, C., 2003, “Shear Analysis of Concrete with Brittle Reinforcement,” Journal of Composites for Construction, ASCE, V. 7, No. 4, pp. 323-330. doi: 10.1061/(ASCE)1090-0268(2003)7:4(323)
Swamy, R. N., and Bahia, H. M., 1985, “Effectiveness of Steel Fibers as Shear Reinforcement,” Concrete International: Design & Construction (Arlington), V. 7, No. 3, Mar., pp. 35-40.
Swamy, R. N.; Jones, R.; and Chiam, A. T. P., 1993, “Influence of Steel Fibers on the Shear Resistance of Lightweight Concrete I-Beams,” ACI Structural Journal, V. 90, No. 1, Jan.-Feb., pp. 103-114.
Untrauer, R. E., and Henry, R. L., 1965, “Influence of Normal Pressure on Bond Strength,” ACI Journal Proceedings, V. 62, No. 5, May, pp. 577-586.
Vecchio, F. J., and Collins, M. P., 1986, “The Modified Compression-Field Theory for Reinforced Concrete Elements Subjected to Shear,” ACI Structural Journal, V. 83, No. 2, Mar.-Apr., pp. 219-231.
Walraven, J. C., 1981, “Fundamental Analysis of Aggregate Interlock,” Journal of Structural Engineering, ASCE, V. 107, No. 11, pp. 2245-2270.
Yoon, Y.-S.; Cook, W. D.; and Mitchell, D., 1996, “Minimum Shear Reinforcement in Normal, Medium, and High-Strength Concrete Beams,” ACI Structural Journal, V. 93, No. 5, Sept.-Oct., pp. 1-9.
Zarrinpour, M. R., and Chao, S.-H., 2017, “Shear Strength Enhancement Mechanisms of Steel Fiber-Reinforced Concrete Slender Beams,” ACI Structural Journal, V. 114, No. 3, May-June, pp. 729-742. doi: 10.14359/51689449