Punching shear behavior of flat slabs composed of normal concrete and ECC under the unbalanced moment

Document Type : Research Article

Author

Civil, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

Abstract

Load capacity and ductility are the two main characteristics of flat slab-column connections in highly seismic areas. To date, different methods have been employed to strengthen the connection against shear punching, including column capital, drop panel, high strength concrete, and shear reinforcement. In the current experimental study, the effect of using Engineered Cementitious Composite (ECC) on upgrading the punching shear strength of flat slabs under an unbalanced moment was investigated. ECC can provide the composite with features such as the ability to spread multiple cracks under load, strain hardening, shear force, scabbing strength, and high deformation. To this end, seven reinforced concrete flat slab specimens with the dimensions of 1000mm*1000mm*100 mm under the load with the eccentricity of 150mm were examined. The slabs were made from two layers of normal concrete and ECC in their thicknesses. The variable parameters included the unbalanced moment effect, improved interaction of the two materials, and ECC thickness. It was observed that improving the contact surface of normal concrete and ECC increased the shear capacity. In addition, the replacement of slab concrete with ECC increases the punching capacity and post-punching strength of the slab without a large and sudden drop in load. The change in failure mechanism was observed from a sudden and abrupt failure to a formable failure with high-energy absorption when using more ECC layer thicknesses.

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Main Subjects

References

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Amirkabir Journal of Civil Engineering
Volume 53, Issue 10
January 2022
Pages 4519-4534

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