Author: Bayan S. Al Numan1
1Civil Engineering Department, Faculty of Engineering, Tishk International University, Erbil, Iraq
Abstract: This work studies the behavior of high strength concrete (HSC) slabs after exposure to high temperatures, and proposes punching strength-temperature relationship for HSC panels based on previous experimental work of the author, which tested reinforced HSC slab specimens subjected to four exposure levels. The HSC slabs have cube compressive strength of 94 MPa. The paper investigates the punching strength of HSC panels, load deflection behavior, crack patterns and failure modes and characteristics, as the temperature level of exposure is increased. The punching and compressive strengths reduced with the increase in the temperature of exposure. A parabolic equation is established that relates both strengths with the temperature of exposure. When temperature reaches 700 oC, the residual punching strength obtained was 54% of that at room temperature, and the type of failure was a flexural failure followed by punching shear failure.
Keywords: Punching Strength, High Strength Concrete, High Temperature Exposure
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American Concrete Institute ACI Code (318-2014). Building code requirements for reinforced concrete. American Concrete Institute, Detroit, Mich.
Alnuman, B. S., & Muhammed, N. J. (2012). Residual punching strength of NSC, HSC, and LWC panels exposed to high temperatures. Journal of Engineering and Development, 16 (3), 190-210.
ASTM E119-2000a. (2000). Standard test methods for fire tests of building constructions and materials. Annual Book of ASTM Standards, Vol.04.07, 21p.
Fahmi, H.M., & Heidyat, A. (1996). Behavior of reinforced concrete slabs subjected to high temperatures. Al-Muhandis Journal, 125(1), 5-19.
Harada, T.J., Yamane, S., & Furumura, F. (1972). Strength, Elasticity and Thermal Properties of Concrete Subjected to Elevated Temperature, ACI Special Publication SP 34, 1, 377-406.
Iraqi specification (I.O.S) No..5/1984 Ordinary Portland cement, 9p. (in Arabic).
Iraqi specification (I.O.S) No.45/1984. Normal weight fine aggregate and coarse aggregate in concrete, 21p. (in Arabic).
Lie, T.T., & Leir, G.W. (1979). Factors affecting temperature of fire-exposed concrete slabs. Fire and Materials, 3(2), 74-79.
Shirley, S.T., Burg, R.G., & Fiorato, A.E. (1988). Fire endurance of high-strength concrete slabs. ACI Materials Journal, 85(2), 102-108.
Umran, M.K. (2002). Fire flame exposure effect on some mechanical properties of concrete. M.Sc. Thesis, College of Engineering, University of Babylon, Hilla, Iraq.
Venkatesh, K., Kodur, R., Luke A., & Simon, H., Foo, C. (2005). Thermal behavior of fire-exposed concrete slabs reinforced with fiber-reinforced polymer bars. Structural Journal, 102(6), 799-807.