The Impact of Hybrid Fibers on Punching Shear Strength of Concrete Flat Plates Exposed to Fire


  • A. N. Dalaf Department of Civil Engineering, University of Baghdad, Iraq
  • S. D. Mohammed Department of Civil Engineering, University of Baghdad, Iraq
Volume: 11 | Issue: 4 | Pages: 7452-7457 | August 2021 |


This study presents an investigation about the effect of fire flame on the punching shear strength of hybrid fiber reinforced concrete flat plates. The main considered parameters are the fiber type (steel or glass) and the burning steady-state temperatures (500 and 600°C). A total of 9 half-scale flat plate specimens of dimensions 1500mm×1500mm×100mm and 1.5% fiber volume fraction were cast and divided into 3 groups. Each group consisted of 3 specimens that were identical to those in the other groups. The specimens of the second and the third groups were subjected to fire flame influence for 1 hour and steady-state temperature of 500 and 600°C respectively. Regarding the cooling process, water sprinkling was applied directly after the burning stage to represent the sudden cooling process. Generally, the obtained results exhibited a significant increase in the punching shear capacity of the fiber-reinforced slabs as compared to the corresponding no fiber-reinforced slabs even at elevated burning temperatures 600°C. The ultimate load was increased by about 16.6, 19, and 21.5% at temperatures of 25, 500, and 600°C respectively, for steel fiber reinforced slabs and by about 13.9, 27.2, and 34.6% for slabs containing two mixed types of fibers (steel and glass), as compared with the reference specimen at the same temperatures respectively. In addition, the results indicated that fibers' presence in concrete resulted in gradually punching failure with more ductile mode, whereas the failure was sudden with a brittle mode in the slabs that did not contain fibers.


Steel fibers, hybrid fibers, Punching shear


Download data is not yet available.


M. K. Jawad, "Experimental Study on shear heads in reinforced concrete flat plates," Ph.D. dissertation, Al-Mustansiriya University, Baghdad, Iraq, 2005.

P. Menétrey, "Synthesis of punching failure in reinforced concrete," Cement and Concrete Composites, vol. 24, no. 6, pp. 497–507, Dec. 2002.

G. A. Khoury, "Effect of fire on concrete and concrete structures," Progress in Structural Engineering and Materials, vol. 2, no. 4, pp. 429–447, 2000.

A. I. Abdullah and S. D. M. Al-Khazraji, "Structural Behavior of High Strength Laced Reinforced Concrete One Way Slab Exposed to Fire Flame," Civil Engineering Journal, vol. 5, no. 12, pp. 2747–2761, Dec. 2019.

A. A. Hammadi, A. F. Izzat, and J. A. Farhan, "Effect of Fire Flame (High Temperature) on the Self Compacted Concrete (SCC) One Way Slabs," Journal of Engineering, vol. 18, no. 10, pp. 1083–1099, 2012.

S. Mohammed and N. Fawzi, "Fire Flame Influence on the Behavior of reinforced Concrete Beams Affected by Repeated Load," Journal of Engineering, vol. 22, no. 9, pp. 206–223, Sep. 2016.

I. A. Fletcher, S. Welch, J. L. Torero, R. O. Carvel, and A. Usmani, "Behaviour of concrete structures in fire," Thermal Science, vol. 11, no. 2, pp. 37–52, 2007.

H. Salem, H. Issa, H. Gheith, and A. Farahat, "Punching shear strength of reinforced concrete flat slabs subjected to fire on their tension sides," HBRC Journal, vol. 8, no. 1, pp. 36–46, Apr. 2012.

M. I. M. Rjoub, "Moment capacity of steel fiber reinforced concrete beams," JES. Journal of Engineering Sciences, vol. 34, no. 2, pp. 413–422, Mar. 2006.

S. T. Tassew and A. S. Lubell, "Mechanical properties of glass fiber reinforced ceramic concrete," Construction and Building Materials, vol. 51, pp. 215–224, Jan. 2014.

H. A. Hamid and S. D. Mohammed, "Behavior of Reinforced Reactive Powder Concrete Two-Way Slabs under Static and Repeated Load," Civil Engineering Journal, vol. 4, no. 6, pp. 1178–1192, Jul. 2018.

S. D. B. ALlexander and S. H. Simmonds, "Punching Shear Tests of Concrete Slab-Column Joints Containing Fiber Reinforcement," Structural Journal, vol. 89, no. 4, pp. 425–432, Jul. 1992.

R. K. Aboud, H. K. Awad, and S. D. Mohammed, "Fire flame effect on the compressive strength of reactive powder concrete using different methods of cooling," IOP Conference Series Materials Science and Engineering, no. 518, Nov. 2019.

B. H. A. Bakar, A. T. Noaman, and H. M. Akil, "Cumulative Effect of Crumb Rubber and Steel Fiber on the Flexural Toughness of Concrete," Engineering, Technology & Applied Science Research, vol. 7, no. 1, pp. 1345–1352, Feb. 2017.

B. Gebretsadik, K. Jadidi, V. Farhangi, and M. Karakouzian, "Application of Ultrasonic Measurements for the Evaluation of Steel Fiber Reinforced Concrete," Engineering, Technology & Applied Science Research, vol. 11, no. 1, pp. 6662–6667, Feb. 2021.

M. K. Jawad, "Experimental study on shear heads in reinforced concrete flat plates," M.S. thesis, University of Babylon, Al Hillah, Iraq, 2002.

L. Nguyen-Minh, M. Rovňák, T. Tran-Quoc, and K. Nguyenkim, "Punching Shear Resistance of Steel Fiber Reinforced Concrete Flat Slabs," Procedia Engineering, vol. 14, pp. 1830–1837, Jan. 2011.

ACI Committee 318, ACI CODE-318-19: Building Code Requirements for Structural Concrete and Commentary. ACI, 2019.

E. T. Dawood and M. Ramli, "Contribution of Hybrid Fibers on the Properties of High Strength Concrete Having High Workability," Procedia Engineering, vol. 14, pp. 814–820, Jan. 2011.

K.-K. Choi, H.-G. Park, and H.-M. Kim, "Shear Strength Model for Slab-Column Connections," Journal of the Korea Concrete Institute, vol. 22, no. 4, pp. 585–593, Aug. 2010.


How to Cite

A. N. Dalaf and S. D. Mohammed, “The Impact of Hybrid Fibers on Punching Shear Strength of Concrete Flat Plates Exposed to Fire”, Eng. Technol. Appl. Sci. Res., vol. 11, no. 4, pp. 7452–7457, Aug. 2021.


Abstract Views: 74
PDF Downloads: 46

Metrics Information
Bookmark and Share

Most read articles by the same author(s)