Title:
Shear Behavior of Thermally Damaged Reinforced Concrete Beams
Author(s):
Subhan Ahmad, Pradeep Bhargava, and Minkwan Ju
Publication:
Structural Journal
Volume:
119
Issue:
4
Appears on pages(s):
251-261
Keywords:
elevated temperature; longitudinal reinforcement ratio; shear behavior; shear span-depth ratio; short beam
DOI:
10.14359/51734665
Date:
7/1/2022
Abstract:
Sixteen shear-critical reinforced concrete short beams (RCSB) with different percentages of tension reinforcement were loaded until failure at ambient and after 350, 550, and 750°C temperatures. Elevated temperatures resulted in a higher shear capacity loss in the beams with a lower tension reinforcement. Stiffness of the beams reduced, whereas midspan deflection corresponding to ultimate load increased after elevated temperatures. Load-shear crack width responses indicated a brittle failure in the beams up to a temperature of 350°C. Ductile failure was perceived in the specimens tested after 550 and 750°C. The strains in tension reinforcement corresponding to ultimate load decrease as the exposure temperature increases. Theoretical predictions provided reasonable estimates of shear capacities up to a temperature of 350°C; in contrast, shear capacities of beams exposed to over 550°C were found up to 46% higher. The experimental results were used to
develop an equation for the computation of the shear capacity of RCSB after exposure to elevated temperatures.
Related References:
1. ElMohandes, F., “Advanced Three-Dimensional Nonlinear Analysis of Reinforced Concrete Structures Subjected to Fire and Extreme Loads,” PhD dissertation, University of Toronto, Toronto, ON, Canada, 2013, 428 pp.
2. Morley, P. D., “Effects of Elevated Temperature on Bond in Reinforced Concrete,” PhD dissertation, University of Edinburgh, Edinburgh, UK, 1982, 315 pp.
3. Naus, D. J., “The Effect of Elevated Temperature on Concrete Materials and Structures—A Literature Review,” U.S. Nuclear Regulatory Commission, Oak Ridge National Laboratory, Oak Ridge, TN, 2006, 204 pp.
4. Ellingwood, B., and Lin, T. D., “Flexure and Shear Behavior of Concrete Beams during Fires,” Journal of Structural Engineering, ASCE, V. 117, No. 2, Feb. 1991, pp. 440-458. doi: 10.1061/(ASCE)0733-9445(1991)117:2(440)
5. Yamazaki, N.; Yamazaki, M.; Mochida, T.; Mutoh, A.; Miyashita, T.; Ueda, M.; Hasegawa, T.; Sugiyama, K.; Hirakawa, K.; Kikuchi, R.; Hiramoto, M.; and Saito, K., “Structural Behavior of Reinforced Concrete Structures at High Temperatures,” Nuclear Engineering and Design, V. 156, No. 1-2, June 1995, pp. 121-138. doi: 10.1016/0029-5493(94)00934-Q
6. El-Hawary, M. M.; Ragab, A. M.; Abd El-Azim, A.; and Elibiari, S., “Effect of Fire on Shear Behaviour of R.C. Beams,” Computers & Structures, V. 65, No. 2, Oct. 1997, pp. 281-287. doi: 10.1016/S0045-7949(95)00356-8
7. Jiang, C.-J.; Yu, J.-T.; Li, L.-Z.; Wang, X.; Wang, L.; and Liao, J.-H., “Experimental Study on the Residual Shear Capacity of Fire-Damaged Reinforced Concrete Frame Beams and Cantilevers,” Fire Safety Journal, V. 100, Sept. 2018, pp. 140-156. doi: 10.1016/j.firesaf.2018.08.004
8. Xing, Q.; Liao, J.; Chen, Z.; and Huang, W., “Shear Behaviour of Fire-Damaged Reinforced-Concrete Beams,” Magazine of Concrete Research, V. 72, No. 7, Apr. 2020, pp. 357-364. doi: 10.1680/jmacr.17.00529
9. Fan, S.; Zhang, Y.; and Tan, K. H., “Experimental and Analytical Studies of Reinforced Concrete Short Beams at Elevated Temperatures,” Engineering Structures, V. 212, June 2020, Article No. 110445. doi: 10.1016/j.engstruct.2020.110445
10. Song, Y.; Fu, C.; Liang, S.; Shi, J.; and Dang, L., “Shear Capacity of Indirectly Loaded Reinforced Concrete Beams under and after Fire Exposure,” Advances in Structural Engineering, V. 23, No. 13, Oct. 2020, pp. 2942-2951. doi: 10.1177/1369433220927262
11. Felicetti, R.; Gambarova, P. G.; and Semiglia, M., “Residual Capacity of HSC Thermally Damaged Deep Beams,” Journal of Structural Engineering, ASCE, V. 125, No. 3, Mar. 1999, pp. 319-327. doi: 10.1061/(ASCE)0733-9445(1999)125:3(319)
12. Khan, M. S.; Prasad, J.; and Abbas, H., “Shear Strength of RC Beams Subjected to Cyclic Thermal Loading,” Construction and Building Materials, V. 24, No. 10, Oct. 2010, pp. 1869-1877. doi: 10.1016/j.conbuildmat.2010.04.016
13. Ahmad, S.; Bhargava, P.; Chourasia, A.; and Ju, M., “Residual Shear Strength of Reinforced Concrete Slender Beams without Transverse Reinforcement after Elevated Temperatures,” Engineering Structures, V. 237, June 2021, Article No. 112163. doi: 10.1016/j.engstruct.2021.112163
14. IS 8112:2013, “Specification for 43 Grade Ordinary Portland Cement,” Bureau of Indian Standards, New Delhi, India, 2013, 17 pp.
15. IS 1786:2008, “High Strength Deformed Steel Bars and Wires for Concrete Reinforcement,” Bureau of Indian Standards, New Delhi, India, 2008, 22 pp.
16. IS 1608:2005, “Metallic Materials – Tensile Testing at Ambient Temperature,” Bureau of Indian Standards, New Delhi, India, 2005, 51 pp.
17. IS 10262:2009, “Guidelines for Concrete Mix Design Proportioning,” Bureau of Indian Standards, New Delhi, India, 2009, 21 pp.
18. Schneider, U., “Concrete at High Temperatures—A General Review,” Fire Safety Journal, V. 13, No. 1, Apr. 1988, pp. 55-68. doi: 10.1016/0379-7112(88)90033-1
19. Persson, B., “Fire Resistance of Self-Compacting Concrete, SCC,” Materials and Structures, V. 37, No. 9, Nov. 2004, pp. 575-584. doi: 10.1007/BF02483286
20. Ahmad, S.; Bhargava, P.; Chourasia, A.; and Sharma, U. K., “Shear Transfer Strength of Uncracked Concrete after Elevated Temperatures,” Journal of Structural Engineering, ASCE, V. 146, No. 7, July 2020, p. 04020133. doi: 10.1061/(ASCE)ST.1943-541X.0002681.
21. Krefeld, W. J., and Thurston, C. W., “Studies of the Shear and Diagonal Tension Strength of Simply Supported Reinforced Concrete Beams,” ACI Journal Proceedings, V. 63, No. 4, Apr. 1966, pp. 451-476.
22. Taylor, H. P. J., “Investigation of the Dowel Shear Forces Carried by the Tensile Steel in Reinforced Concrete Beams,” Technical Report 431, Cement and Concrete Association, London, UK, 1969, 24 pp.
23. Houde, J., and Mirza, M. S., “A Finite Element Analysis of Shear Strength of Reinforced Concrete Beams,” Shear in Reinforced Concrete, SP-42, American Concrete Institute, Farmington Hills, MI, 1974, pp. 103-128.
24. Jeli, I.; Pavlović, M. N.; and Kotsovos, M. D., “A Study of Dowel Action in Reinforced Concrete Beams,” Magazine of Concrete Research, V. 51, No. 2, Apr. 1999, pp. 131-141. doi: 10.1680/macr.1999.51.2.131
25. Jimenez-Perez, R.; Gergely, P.; and White, R. N., “Shear Transfer across Cracks in Reinforced Concrete,” Cornell University, Ithaca, NY, 1978, 375 pp.
26. Ahmad, S.; Umar, A.; Masood, A.; and Nayeem, M., “Performance of Self-Compacting Concrete at Room and After Elevated Temperature Incorporating Silica Fume,” Advances in Concrete Construction, V. 7, No. 1, Feb. 2019, pp. 31-37.
27. Jayasree, G.; Lakshmipathy, M.; and Santhanaselvi, S., “Behaviour of RC Beams under Elevated Temperature,” Journal of Structural Fire Engineering, V. 2, No. 1, Feb. 2011, pp. 45-55. doi: 10.1260/2040-2317.2.1.45
28. Khan, M. R., and Royles, R., “Post Heat Exposure Behaviour of Reinforced Concrete Beams,” Magazine of Concrete Research, V. 38, No. 135, June 1986, pp. 59-66. doi: 10.1680/macr.1986.38.135.59
29. Zhang, B.; Bicanic, N.; Pearce, C. J.; and Phillips, D. V., “Relationship between Brittleness and Moisture Loss of Concrete Exposed to High Temperatures,” Cement and Concrete Research, V. 32, No. 3, Mar. 2002, pp. 363-371. doi: 10.1016/S0008-8846(01)00684-6
30. Kim, D.; Kim, W.; and White, R. N., “Arch Action in Reinforced Concrete Beams—A Rational Prediction of Shear Strength,” ACI Structural Journal, V. 96, No. 4, July-Aug. 1999, pp. 586-593.
31. Sangiorgio, F.; Silfwerbrand, J.; and Mancini, G., “Scatter in the Shear Capacity of Slender RC Members without Web Reinforcement: An Overview Study,” Structural Concrete, V. 17, No. 1, Mar. 2016, pp. 11-20. doi: 10.1002/suco.201400107
32. Joint ACI-ASCE Task Committee 426, “The Shear Strength of Reinforced Concrete Members,” Journal of the Structural Division, ASCE, V. 99, No. 6, June 1973, pp. 114-1157.
33. Zsutty, T. C., “Beam Shear Strength Prediction by Analysis of Existing Data,” ACI Journal Proceedings, V. 65, No. 11, Nov. 1968, pp. 943-951.
34. Zsutty, T., “Shear Strength Prediction for Separate Catagories of Simple Beam Tests,” ACI Journal Proceedings, V. 68, No. 2, Feb. 1971, pp. 138-143.
35. EN 1994-1-2:2005, “Eurocode 4: Design of Composite Steel and Concrete Structures – Part 1-2: General Rules – Structural Fire Design,” European Committee for Standardization, Brussels, Belgium, 2005, 111 pp.