The analysis of the effectiveness of different types of punching shear reinforcement not fully anchored

Tadeusz Urban

Department of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Łódź University of Technology (Poland)

Michał Gołdyn

Department of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Łódź University of Technology (Poland)

Łukasz Krawczyk

Department of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Łódź University of Technology (Poland)
https://orcid.org/0000-0002-0406-7750

Abstract

The paper discusses the issue of load capacity of flat plates with transverse reinforcement situated between the longitudinal reinforcement. Using this types of reinforcement is much more convenient from the installation point of view, however, it does not guarantee complete embedment, as efficient as traditional stirrups that comprise longitudinal reinforcement in compression and the tension zone. The transverse rods do not comprise the main reinforcement, so their slide out of the concrete slabs or cracks parallel to the plane of the longitudinal reinforcement and delamination of the slab can occur.

The different types of transverse reinforcement were presented: system consisting of  ready-made bolts, reinforcement baskets or ladders. Experimental results of plates with  these types of reinforcement are presented. The analysis of effectiveness of reinforcement anchorage indicates that transverse bolts can be used to increase the punching shear load capacity of the plates. The resulting capacity was only of about 20% lower than result elements with complete embedment Experimental results were similar to the theoretical capacity resulting from the consideration by Eurocode 2.

Keywords:

punching shear, transverse reinforcement, anchorage, ready-made inserts