Title:
Shear Behavior of Large-Scale Deep Beams with Lightweight-Aggregate Concrete
Author(s):
Tao Wu, Hui Wei, and Xi Liu
Publication:
Structural Journal
Volume:
117
Issue:
1
Appears on pages(s):
75-89
Keywords:
deep beams; lightweight-aggregate concrete; shear behavior; size effect; STM-based shear models
DOI:
10.14359/51718009
Date:
1/1/2020
Abstract:
Fifteen lightweight-aggregate concrete (LWAC) deep beams subjected to symmetric concentrated loading were tested for the study of shear behavior and size effect. The test variables include beam depths (h ranged from 500 to 1400 mm [19.7 to 55.2 in.]), shear span-depth ratios (a/h = 0.75, 1.00, and 1.50), and bearing plate widths (130 and 200 mm [5.12 and 7.88 in.]). The test results showed that all specimens failed in shear-compression mode. As a/h increased, the specimen failure gradually occurred more gently. Additionally, the bearing plate width had a slight influence on the crack pattern of the specimens. The normalized shear strength at failure decreased by approximately 37.1% when h increased from 500 to 1400 mm (19.7 to 55.2 in.), indicating remarkable size dependence. The accuracy and applicability of four current codes and two size-effect models were then verified by the test results. A comparison study revealed that the ACI 318-14 code and Tan-Cheng’s model are more accurate in predicting the size effect on the shear strength of LWAC deep beams, while estimations from AASHTO LRFD are over-conservative for specimens with an a/h of 1.5.
Related References:
1. Lu, W. Y.; Lin, I. J.; and Yu, H. W., “Shear Strength of Reinforced Concrete Deep Beams,” ACI Structural Journal, V. 110, No. 4, July-Aug. 2013, pp. 671-680.
2. Yang, K.-H.; Chung, H.-S.; Lee, E.-T.; and Eun, H.-C., “Shear Characteristics of High-Strength Concrete Deep Beams without Shear Reinforcements,” Engineering Structures, V. 25, No. 10, 2003, pp. 1343-1352. doi: 10.1016/S0141-0296(03)00110-X
3. Tan, K. H.; Cheng, G. H.; and Zhang, N., “Experiment to Mitigate Size Effect on Deep Beams,” Magazine of Concrete Research, V. 60, No. 10, 2008, pp. 709-723. doi: 10.1680/macr.2007.00030
4. Brena, S. F., and Roy, N. C., “Evaluation of Load Transfer and Strut Strength of Deep Beams with Short Longitudinal Bar Anchorages,” ACI Structural Journal, V. 106, No. 5, Sept.-Oct. 2009, pp. 678-689.
5. Mihaylov, B. I.; Bentz, E. C.; and Collins, M. P., “Behavior of Large Deep Beam Subjected to Monotonic and Reversed Cyclic Shear,” ACI Structural Journal, V. 107, No. 6, Nov.-Dec. 2010, pp. 726-734.
6. Kong, F. K., and Robins, P. J., “Web Reinforcement Effects on Lightweight Concrete Deep Beams,” ACI Journal Proceedings, V. 68, No. 7, July 1971, pp. 514-520.
7. Ahmad, S. H.; Xie, Y.; and Yu, T., “Shear Ductility of Reinforced Lightweight Concrete Beams of Normal Strength and High Strength Concrete,” Cement and Concrete Composites, V. 17, No. 2, 1995, pp. 147-159. doi: 10.1016/0958-9465(94)00029-X
8. Kong, F. K.; Teng, S.; Singh, A.; and Tan, K. H., “Effect of Embedment Length of Tension Reinforcement on the Behavior of Lightweight Concrete Deep Beams,” ACI Structural Journal, V. 93, No. 1, Jan.-Feb. 1996, pp. 23-29.
9. Yang, K. H., and Mun, J. H., “Effect of Aggregate Size on the Shear Capacity of Lightweight Concrete Continuous Beams,” Journal of the Korea Concrete Institute, V. 21, No. 5, 2009, pp. 669-677. doi: 10.4334/JKCI.2009.21.5.669
10. Yang, K. H., “Tests on Lightweight Concrete Deep Beams,” ACI Structural Journal, V. 107, No. 6, Nov.-Dec. 2010, pp. 663-670.
11. Wu, T.; Wei, H.; and Liu, X., “Experimental Investigation of Shear Models for Lightweight Aggregate Concrete Deep Beams,” Advances in Structural Engineering, V. 21, No. 1, 2018, pp. 109-124. doi: 10.1177/1369433217711618
12. Walraven, J., and Lehwalter, N., “Size Effects in Short Beams Loaded in Shear,” ACI Structural Journal, V. 91, No. 5, Sept.-Oct. 1994, pp. 585-593.
13. Tan, K. H., and Lu, H. Y., “Shear Behavior of Large Reinforced Concrete Deep Beams and Code Comparisons,” ACI Structural Journal, V. 96, No. 5, Sept.-Oct. 1999, pp. 836-845.
14. Zhang, N., and Tan, K. H., “Size Effect in RC Deep Beams: Experimental Investigation and STM Verification,” Engineering Structures, V. 29, No. 12, 2007, pp. 3241-3254. doi: 10.1016/j.engstruct.2007.10.005
15. Matsuo, M.; Lertsrisakulrat, T.; Yanagawa, A.; and Niwa, J., “Shear Behavior in RC Deep Beams with Stirrups,” Transactions of the Japan Concrete Institute, V. 23, No. 5, 2002, pp. 385-390.
16. Birrcher, D.; Tuchscherer, R.; Huizinga, M.; Bayrak, O.; Wood, S.; and Jirsa, J., “Strength and Serviceability Design of Reinforced Concrete Deep Beams,” Report No. 0-5253-1, Center for Transportation Research, University of Texas at Austin, Austin, TX, Mar. 2009, 400 pp.
17. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318M-14) and Commentary (ACI 318RM-14),” American Concrete Institute, Farmington Hills, MI, 2014, 520 pp.
18. AASHTO, “AASHTO LRFD Bridge Design Specifications,” American Association of State Highway and Transportation Officials, Washington, DC, 2012, 1635 pp.
19. British Standards Institution, “Eurocode 2: Design of Concrete Structures: Part 1-1: General Rules and Rules for Buildings,” British Standards Institution, London, UK, 2004, 97 pp.
20. International Federation for Structural Concrete, “Model Code 2010 – First Complete Draft,” fib Bulletin No. 55, 2010, 288 pp.
21. Tan, K. H., and Cheng, G. H., “Size Effect on Shear Strength of Deep Beams: Investigating with Strut-and-Tie Model,” Journal of Structural Engineering, ASCE, V. 132, No. 5, 2006, pp. 673-685. doi: 10.1061/(ASCE)0733-9445(2006)132:5(673)
22. Bažant, Z. P., and Kazemi, M. T., “Size Effect on Diagonal Shear Failure of Beams without Stirrups,” ACI Structural Journal, V. 88, No. 3, May-June 1991, pp. 268-276.
23. Wu, T.; Yang, X.; Wei, H.; and Liu, X., “Mechanical Properties and Microstructure of Lightweight Aggregate Concrete with and without Fibers,” Construction and Building Materials, V. 199, 2019, pp. 526-539. doi: 10.1016/j.conbuildmat.2018.12.037