Issues‎ > ‎vol4n5en‎ > ‎

sjes-10055


Load –Deflection Relationship for Clamped- Horizontally Restrained R.C. Polygonal Slabs
Dr. Ali Flayeh Hassan
Department of Civil Engineering, University of Duhok
Received : 25/01/2017, Accepted : 24/05/2017
DOI Link: https://doi.org/10.17656/sjes.10055
ABSTRACT


     A theoretical model is presented in the analysis and prediction of the complete load-deflection behavior of fixed-horizontally restrained reinforced concrete polygonal slabs under uniform loading. The limiting cases of fixed reinforced concrete square and circular slabs are also deduced. The proposed model considers three stages, elastic, elasto-plastic and plastic. In the elastic and -elasto-plastic stages, the results of classical plate theory are used. The cracking of concrete and yielding of steel reinforcement are accounted for by suitably modifying flexural rigidity. Changes that occur in support conditions due to possible yielding are also considered. In the plastic stage a rigid plastic membrane analysis is presented. A method is proposed to predict the real ultimate load (including membrane action) and the deflection at the ultimate load.

KEYWORDS :Circular slabs, polygonal slab, square slabs, flexural rigidity, membrane action, yield criterion, yield-line theory.

REFERENCES:
1- Wood, R.H., “Plastic and Elastic Design of Slabs and Plates” Thomas and Hudson, London, England, 1961.
2- Hopkins,D.C, and Park ,R. ̋ Test on a Reinforced Concrete Slab and Beam Floor Designed with Allowance for Membrane Action ̋ . Cracking, Deflection and Ultimate Load of Concrete Slab Systems. ACI Special Publication 30, American Concrete Institute, Detroit, 1971, PP. 223-250
3- Datta,T.K., and Ramesh ,C.K., ̋ Some Experimental Studies on a Reinforced Concrete Slab- Beam System ̋. Magazine of Concrete Research, London, England, Vol.27, 1975, PP.111-120
4- Foster, S., J, Bailey, C, G, Burgess, I. W. and Plank, R. J., “Experimental Behavior of Concrete Floor Slabs at Large Displacement ˮ, Engineering Structures, April, 2004. Pp. 1231 – 1247.
5- Kumar. V. and Harish, V., “Experimental Study on Deformation Behavior of Partially Restrained Steel Fiber Reinforced High Strength SCC Two Way Rectangular Slabs”, International Research Journal of Engineering and Technology, Vol.2, Juley (2015), pp. 830 -835.
6- Johansen, K.W., ̋ Yield-line Theory ̋, Cement and Concrete Association, London,1962, PP.181
7- Park,R, ̋ The Ultimate Strength of Rectangular Concrete Slabs under Short- Term Uniform Loading with Edges Restrained Against Lateral Movement ̋ , Proceedings of the Institution of Civil Engineers, London, England, Vol.28,June ,1964,PP.125-150
8- Al-Hassaini, H.M, ̋ Ultimate Strength of Clamped R.C. Rectangular Slab, ̋ Journal of Engineering and Technology,Vol. 12 , No.4 ,1993,PP.71-103
9- Timoshenko,S.P.and Woinowsky-krieger,s., ̋Theory of Plates and Shells ̋, 2nd Edition,McGraw-Hill, New York,1959
10- Young,W.C. and Budyans,R.Q. ̋ Roark’s Formulas for Stress and Strains, ̋7th Edition,MCGraw- Hill, New York,2002
11- Building Code Requirements for Reinforced Concrete (ACI 318-11), American Concrete Institute, Detroit,2011
12- British Standard Code of Practice C.P.114 (1957), ̋ The Structural Use of Concrete ̋.