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Effect of Web Reinforcement on Shear Strength of Deep Beams and Crack Propagation

Naresh Dixit, Mohammed Zubair, Hemang Vishrut

Abstract


Reinforced concrete deep beams are known to display complex behaviour. This is due to their exceptionally high beam depth when compared to normal shallow beams. Their strength capacity is mainly governed by their shear strength due to their geometric proportions. It is also governed by a number of parameters, which include size of the beam, strength of the concrete used, placement and amount of tensile and web reinforcement used and the shear span-to-depth ratio. While a lot of research has been conducted on how these parameters affect the shear strength of deep beams, this study aims to find the effect of web reinforcement on deep beams by determining the optimum spacing of web reinforcement for a particular shear span-to-depth ratio. 76 beams were tested with different span-to depth ratios, amount of reinforcement used, depth of beams and time of curing. It was found that when the span-to depth ratio was 1, there was a 34.10%, 11.30% and 16.89% increase in shear strength when compared to normal beams having span-to-depth ratio 2 with web reinforcement spacing 125mm, 150mm and 175mm c/c at 28 days of curing respectively. Similarly, for the same span-to-depth ratio, there was a 14.77%, 8.72% and 10.18% increase in the shear strength at 56 days when compared to normal beams having 125mm, 150mm and 175mm c/c web reinforcement spacing respectively. The modes of beam failure were influenced by the depth of beam and the amount of shear reinforcement.

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References


AASHTO, L. (2008). Bridge design specifications, customary US units, with 2008 interim revisions. American Association of State Highway and Transportation Officials, Washington, DC, 80.

ACI Committee 318. (2014). Building Code Requirements for Structural Concrete (ACI 318-14)[and] Commentary on Building Code Requirements for Structural Concrete (ACI 318R-14).

Aguilar, G., Matamoros, A. B., Parra-Montesinos, G., Ramírez,

J. A., & Wight, J. K. (2002). Experimental evaluation of design procedures for shear strength of deep reinforced concrete beams. American Concrete Institute.

Angelakos, D., Bentz, E. C., & Collins, M. P. (2001). Effect of concrete strength and minimum stirrups on shear strength of large members. Structural Journal, 98(3), 291-300.

Ashour, A. F., & Morley, C. T. (1996). Effectiveness factor of concrete in continuous deep beams. Journal of Structural Engineering, 122(2), 169-178..

Ashour, A. F. (2000). Shear capacity of reinforced concrete deep beams. Journal of Structural Engineering, 126(9), 1045-1052.

Bakir, P. G., & Boduroǧlu, H. M. (2005). Mechanical behavior and non-linear analysis of short beams using softened truss and direct strut & tie models. Engineering Structures, 27(4), 639-651.

Collins, M. and Kuchma, D. 1999. How safe are our large, lightly reinforced concrete beams, slabs, and footings. ACI Str Jl, .96(4): 482-490.

Guide, C. I. R. I. A. (1977). 2: The design of deep beams in reinforced concrete. Ove Arup and Partners, Construction Industry Research and Information Association, London.


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