Gábor Németh’s research while affiliated with Budapest University of Technology and Economics and other places

The most widely used shear connector of steel‐concrete composite beams is the well‐known headed stud and it can be used for innovative bridge girders with trapezoidal webs embedded in concrete slab as well by horizontally placing the studs on the embedded steel part. Another option for trapezoidal web girders is the closed or open cuts on the corrugated web profile with rebars. In literature, experimental tests and investigation of these kind of shear connectors of embedded steel webs can be found. The focus of the research presented in the paper is on the ductility of embedded trapezoidal corrugated webs with additional mechanical shear connectors. Previous researches have already found that these kind of innovative shear connections have a really advantageous ductile behavior, however further analysis is useful to confirm and investigate their behavior in more details. Force‐displacement diagrams of push‐out experiments of corrugated steel profiles embedded into concrete slab are published in literature and those diagrams serve as a basis of this study. Both elastic and plastic phases of the curves are evaluated, also ductility is analyzed according to the principles of Eurocode.

The application of steel trapezoidal corrugated web in steel-concrete composite girders has been widespread in building structures and has also appeared in bridges for a few decades, due to their advantageous mechanical properties. Embedding the trapezoidal web in the concrete slab leads to additional advantages such as omitting the welds of the top flange, a greater extent of the accordion effect and extra resistance in the load transfer between the two materials. Despite these advantages and their increasing use, there are not many experimental studies to analyse the behaviour of the embedded trapezoidal web and its involvement in shear connection resistance. In order to expand the experimental studies, laboratory tests are executed between 2017–18 at the Department of Structural Engineering of the Budapest University of Technology and Economics on large-scale test specimens, with a total number of 43 embedded specimens. The current paper introduces the executed test program, the analysed specimens, their specialties regarding the geometrical layout and the obtained results. The paper gives a quantitative comparison of the 43 specimens and evaluates the analysed shear connectors regarding their static performance.

The application of trapezoidal corrugated plate as the web for girders, thanks to a number of favorable features, modernizes the manufacture of steel-concrete composite and hybrid structures and provides an alternative, competitive structure for small, medium and large span beams. However, the traditional headed stud shear connectors on the top flange can be considered obsolete in many ways. By embedding the corrugated steel web to the concrete slab, other types of connections should be used, and the behavior of these kind of connections are really promising. In fact, the embedded corrugated web itself functions as a shear connector, though other additive connectors should be used. To understand the structural behavior and design of these embedded connectors, the first step is the examination of the embedded web. The focus of the research presented in this paper is on the interaction behavior of embedded trapezoidal corrugated webs with additional mechanical shear connectors. As the first steps of the research comprehensive experimental program was completed in the Structural Laboratory of the Department of Structural Engineering in BME. This paper provides an overview for 8 (test) 12 (FE model) specimens of the push-out test program with the aim to introduce the structural behavior of embedded corrugated steel web and the influence of structural parameters on the shear resistance and deformation capacity through experimental and numerical investigations.

Traditionally in steel‐concrete composite bridges, the structural elements with different materials are work together with headed stud shear connectors welded to the top flange of the steel beam. The application of trapezoidal corrugated web embedded in the concrete slab provides an alternative for steel‐concrete composite and hybrid structures, however requires new solutions for shear connectors. The paper focusing on the corrugated web type composite and hybrid girders with embedded shear connector called concrete dowel. The paper provides an overview of the push‐out test program performed in the Structural Laboratory of the Department of Structural Engineering in BME.

Hybrid girders with corrugated web are increasingly used in bridge engineering due to its numerous favorable properties. For the web-to-slab connection different layouts have been developed in the past, however, just a few design proposals can be found in the international literature for the determination of the connection’s resistance, especially for the embedded types. In case of these connections the corrugated web is simply embedded into the concrete slab strengthened by transverse rebars through concrete dowels or horizontal headed studs welded to the web. The aim of the current research program is to investigate the structural behavior and the shear capacity of embedded connections by full scale push-out tests. In the current paper the results of 5 push-out tests are introduced having different embedded connection types investigating (i) the effect of the embedding depth, (ii) the existence of the concrete dowels (through cut-outs in the steel web) with transverse rebars and (iii) the influence of the steel flange. These parameters may have significant influence on the behavior and capacity of embedded type connections, which are studied in the research program. During the tests the applied load and the slip between the steel web and concrete slabs are measured in order to study the initial stiffness, the ductility and the shear capacity of the connections.