Title:
Effects of Accident Thermal Loading on Shear Behavior of Reinforced Concrete Members
Author(s):
Kadir C. Sener, Saahastaranshu R. Bhardwaj, and Amit H. Varma
Publication:
Structural Journal
Volume:
116
Issue:
3
Appears on pages(s):
39-52
Keywords:
flexural stiffness; nuclear power plants; out-of-plane shear; reinforced concrete; shear stiffness; shear strength tests; thermal concrete cracking; thermal gradient
DOI:
10.14359/51713305
Date:
5/1/2019
Abstract:
This paper presents the findings from an experimental research project comprised of six full-scale reinforced concrete (RC) beam specimens that were subjected to combination of thermal and mechanical loads. The specimens were designed to represent typical structural members in nuclear structures. These specimens were subjected to accident thermal condition followed by mechanical loading up to failure. The parameters included in the investigation were: 1) maximum accident temperature (300 and 450°F [148.9 and 232.2°C]); 2) concrete clear cover (0.75 and 1.5 in. [19 and 38.1 mm]); and 3) one- or two-sided heating. The experimental results were used to evaluate the flexural and shear stiffness and strength of the tested specimens. The results indicate that accident thermal conditions reduce the shear strength and stiffness of RC beam specimens relative to the ambient values. The nominal shear strength calculated using ACI provisions conservatively estimated the strength of most RC beam specimens at elevated temperatures, but unconservatively estimated the strength of beams with severe heating (450°F [232.2°C]) and reduced clear cover of 0.75 in. (19 mm).
Related References:
1. ACI Committee 349, “Code Requirements for Nuclear Safety-Related Concrete Structures (ACI 349-06) and Commentary,” American Concrete Institute, Farmington Hills, MI, 2006, 6 pp.
2. AISC N690s1, “Specification for Safety-Related Steel Structures for Nuclear Facilities Including Supplement No. 1,” American Institute of Steel Construction, Chicago, IL, 2015.
3. Bae, S., “Thermal-Induced Uniform Strains and Curvatures Calculated Using Equivalent Linear Temperature Distributions,” Nuclear Engineering and Design, V. 250, 2012, pp. 42-52. doi: 10.1016/j.nucengdes.2012.05.032
4. Bhardwaj, S. R.; Varma, A. H.; and Sener, K. C., “Multi-Hazard Assessment and Testing of Structural Walls: Seismic and Thermal Demands,” Proceedings of the 11th National Conference in Earthquake Engineering, Earthquake Engineering Research Institute, Los Angeles, CA, 2018.
5. Bhardwaj, S. R.; Sener, K. C.; and Varma, A. H., “Multi-Hazard Investigation and Testing of Steel-Plate Composite (SC) Wall Piers: Seismic and Thermal Loads,” Nuclear Engineering and Design, V. 348, 2019, pp. 121-130. doi: 10.1016/j.nucengdes.2019.03.026.
6. Yang, Y.; Varma, A. H.; Kreger, M.; and Bradt, T., “Shear Strength and Behavior of RC Structures with T-Headed Bars for Shear Reinforcement.” Transactions of the 23rd International Conference on Structural Mechanics in Reactor Technology (SMiRT-23), Manchester, UK, Aug. 10-14, 2015.
7. Sener, K. C.; Varma, A. H.; and Bhardwaj, S. R., “Accident Thermal Loading Effects on Seismic Behaviour of Safety-Related Nuclear Structures,” Transactions of the 23rd International Conference on Structural Mechanics in Reactor Technology (SMiRT-23), Manchester, UK, Aug. 10-14, 2015.
8. Castillo, C., and Durrani, A. J., “Effect of Transient High Temperature on High-Strength Concrete,” ACI Materials Journal, V. 87, No. 1, Jan.-Feb. 1990, pp. 47-53.
9. Lee, J. S.; Xi, Y.; and Willam, K., “Properties of Concrete after High Temperature Heating and Cooling,” ACI Materials Journal, V. 105, No. 4, July-Aug. 2008, pp. 334-341.
10. Bamonte, P., and Gambarova, P. G., “Thermal and Mechanical Properties at High Temperature of a Very High-Strength Durable Concrete,” Journal of Materials in Civil Engineering, ASCE, V. 22, No. 6, 2010, pp. 545-555. doi: 10.1061/(ASCE)MT.1943-5533.0000058
11. Lin, T. D.; Gustaferro, A. H.; and Abrams, M. S., “Fire Endurance of Continuous Reinforced Concrete Beams,” PCA R&D Bulletin, Portland Cement Association, Skokie, IL, 1981, 23 pp.
12. Dotreppe, J. C., and Franssen, J. M., “The Use of Numerical Models for the Fire Analysis of Reinforced Concrete and Composite Structures,” Engineering Analysis, V. 2, No. 2, 1985, pp. 67-74. doi: 10.1016/0264-682X(85)90056-5
13. Lin, T. D.; Ellingwood, B.; and Piet, O., “Flexural and Shear Behavior of Reinforced Concrete Beams during Fire Tests,” PCA R&D Bulletin, Portland Cement Association, Skokie, IL, 1988.
14. Shi, X.; Tan, T. H.; Tan, K. H.; and Guo, Z., “Effect of Force-Temperature Paths on Behaviors of Reinforced Concrete Flexural Members,” Journal of Structural Engineering, ASCE, V. 128, No. 3, 2002, pp. 365-373. doi: 10.1061/(ASCE)0733-9445(2002)128:3(365)
15. ENV 1994-1-1, “Eurocode 4: Design of Steel and Concrete Composite Structures Part 1.1: General Rules and Rules for Building,” European Committee for Standardization, Brussels, Belgium, 2004.
16. AISC 360-10, “Specification for Structural Steel Buildings,” American Institute of Steel Construction, Chicago, IL, 2010.
17. Vecchio, F. J., and Sato, J. A., “Thermal Gradient Effects in Reinforced Concrete Frame Structures,” ACI Structural Journal, V. 87, No. 3, May-June 1990, pp. 262-275.
18. Vecchio, F. J.; Agostino, N.; and Angelakos, B., “Reinforced Concrete Slabs Subjected to Thermal Loads,” Canadian Journal of Civil Engineering, V. 20, No. 5, 1993, pp. 741-753. doi: 10.1139/l93-099
19. Booth, P. N.; Varma, A. H.; Sener, K. C.; and Malushte, S. R., “Flexural Behavior and Design of Steel-Plate Composite (SC) Walls for Accident Thermal Loading,” Nuclear Engineering and Design, V. 295, 2015, pp. 817-828. doi: 10.1016/j.nucengdes.2015.07.036
20. Bhardwaj, S. R.; Varma, A. H.; and Sener, K. C., “On the Calculation of Design Demands for Accident Thermal Loading Combination,” Transactions of the 23rd International Conference on Structural Mechanics in Reactor Technology (SMiRT-23), Manchester, UK, Aug. 10-14, 2015.
21. ASTM A706/A706M-13, “Standard Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete Reinforcement,” ASTM International, West Conshohocken, PA, 7 pp.