The Consequence of the Involvement of Flexural, Compression, and Punching Reinforcement Upon Punching Strength

Ahmed Abdallah Elgohary, Mohammed Rabiee

Abstract


Flat slabs have an important role in concrete buildings due to their architectural flexibility and speed of construction. Punching shear is one of the most important phenomena to be considered during the design of reinforced concrete flat slabs, as this type of failure is brittle and does not predict previously raised alarms before failure. The main factors that affect punching strength in concrete are compressive strength, flexural reinforcement, and punching reinforcement in the form of stirrups, shear studs, or other shapes. This paper is part of a research program operated at the reinforced concrete laboratory of the Faculty of Engineering, Cairo University, to evaluate the contribution of horizontal flexural reinforcement, horizontal compression reinforcement, and vertical punching reinforcement on the punching strength of reinforced concrete flat slabs. In this research, fifteen half-scale specimens are cast and tested. The specimens had dimensions of 1100×1100 mm and a total thickness of 120 mm. All specimens were connected to a square column of dimensions 150×150 mm and loaded at the four corners with a supported span of 1000 mm. The main parameters considered in this research included spacing between stirrups, width of the stirrups, number of stirrup branches, ratio of the compression reinforcement, and ratio of the tension reinforcement. During testing, ultimate capacity, steel strain, cracking pattern, and deformation were recorded. The experimental results were analyzed and compared against values estimated from different international design codes.

 

Doi: 10.28991/CEJ-2024-010-09-014

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Keywords


Punching; Flat Concrete Slabs; Longitudinal Steel; Punching Vertical Reinforcement; Crack Pattern; Load at Ultimate Stage.

References


E.C.P.-203 (2007) Egyptian Code for Design and Construction of Reinforced Concrete Structures. National Housing and Building Research Center, Giza, Egypt.

ACI 318-19. (2019). Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (318R-19), American Concrete Institute (ACI), Michigan, United States. doi:10.14359/51716937.

EN 1992-1-1. (2004). Design of Concrete Structures, Part 1–1: General Rules and Rules for Buildings. European Committee for Standardization, Brussels, Belgium, 2004.

Kinnunen, S., & Nylander, H. S. E. (1960). Punching of concrete slabs without shear reinforcement. Transactions, No. 158, Royal Institute of Technology, Stockholm, Sweden.

Meisami, M. H., Mostofinejad, D., & Nakamura, H. (2014). Strengthening of flat slabs with FRP fan for punching shear. Composite Structures, 119, 305–314. doi:10.1016/j.compstruct.2014.08.041.

Ebead, U. A. A. (2002). Strengthening of reinforced concrete two-way slabs. Ph.D. Thesis, Memorial University of Newfoundland, St. John's, Canada.

Megally, S. H. (1998). Punching shear resistance of concrete slabs to gravity and earthquake forces. Ph.D. Thesis, University of Calgary, Calgary, Canada.

Broms, C. E. (1990). Shear reinforcement for deflection ductility of flat plates. ACI Structural Journal, 87(6), 696–705. doi:10.14359/2988.

Mabrouk, R. T. S., Bakr, A., & Abdalla, H. (2017). Effect of flexural and shear reinforcement on the punching behavior of reinforced concrete flat slabs. Alexandria Engineering Journal, 56(4), 591–599. doi:10.1016/j.aej.2017.05.019.

Raafat, A., Fawzi, A., Metawei, H., & Abdalla, H. (2021). Assessment of stirrups in resisting punching shear in reinforced concrete flat slab. HBRC Journal, 17(1), 61–76. doi:10.1080/16874048.2021.1881422.

Abdel-Rahman, A. M., Hassan, N. Z., & Soliman, A. M. (2018). Punching shear behavior of reinforced concrete slabs using steel fibers in the mix. HBRC Journal, 14(3), 272–281. doi:10.1016/j.hbrcj.2016.11.001.

Afifi, A., Ramadan, M., Farghal Maree, A. M., Ebid, A. M., Zaher, A. H., & Ors, D. M. (2023). Punching Capacity of UHPC Post Tensioned Flat Slabs with and Without Shear Reinforcement: An Experimental Study. Civil Engineering Journal (Iran), 9(3), 567–582. doi:10.28991/CEJ-2023-09-03-06.

Ramadan, M., Ors, D. M., Farghal, A. M., Afifi, A., Zaher, A. H., & Ebid, A. M. (2023). Punching shear behavior of HSC & UHPC post tensioned flat slabs – An experimental study. Results in Engineering, 17, 100882. doi:10.1016/j.rineng.2023.100882.

Nguyen, K. Le, Trinh, H. T., & Pham, T. M. (2024). Prediction of punching shear strength in flat slabs: ensemble learning models and practical implementation. Neural Computing and Applications, 36(8), 4207–4228. doi:10.1007/s00521-023-09296-0.

Khaloo, A., Borhani, M. H., Habibi, O., Tabatabaeian, M., & Askari, S. M. (2024). Experimental and numerical investigation on the performance of GFRP-confined expansive concrete-filled unplasticized polyvinyl chloride tubes. Journal of Thermoplastic Composite Materials, 37(3), 983–1011. doi:10.1177/08927057231190558.

Habibi, O., Youssef, T., Naseri, H., & Ibrahim, K. (2024). Ensemble Learning Models for Prediction of Punching Shear Strength in RC Slab-Column Connections. Civil Engineering Journal, 10, 1–20. doi:10.28991/cej-sp2024-010-01.


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DOI: 10.28991/CEJ-2024-010-09-014

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