Experimental study of shear transfer in slim floor systems using precast concrete hollow core slabs and steel beam with web circular opening

Steel-concrete slim flooring system using precast concrete hollow core slabs and steel beam with web openings is an innovative construction system designed to combine the high bending resistance of both precast prestressed hollow core slabs and steel beam with web openings. This system can provide floor systems with a minimum constructional depth in comparison with ordinary composite floors. The aim of this study was to evaluate in an exploratory way the shear transferring mechanism between the steel beam with circular web opening and the precast hollow-concrete slab. The shear connection is formed by in-situ concrete passes through the web openings and infill the voids of the precast slabs. One push-out test was conducted to investigate the shear transferring mechanism of shear connection and the experimental results were compared to analytical methods. The shear resistance of the shear connection was predicted with good accurate by analytical methods.

Experimental analysis of shear connection effect composite beams with concrete

The subject of this research is the analysis of shear connection effect on the fiber glass reinforced composite beams. The research contains the detailed analysis of materials like concrete and fiber glass reinforced composite. The shear connection has been tested by the experiment of push out test run in the Centre of research and innovation in construction of Technical University of Košice. The shear connection has been tested on two types of connectors used on composite beams. The main idea of this research is find out whether it is possible to use the alternative material, which should substitute the steel. The aim of research is to design a type of connector for fiber reinforced composite materials or another composite materials developping in the world of material engineering. The part od research is devoted to the FEM analysis.

Experimental verification referring to the new shape of the perforated steel strip

Perforated steel strips are used as reliable shear connectors many years. During this time, many different shapes of the openings or recesses were developed to improve the durability and resistance of the shear connection. Behaviour of these strips were mainly verified by experimental research, but many parameters could not be measured. Numerical analysis provides not only easy and fast way of testing the behaviour of specimens, but also the possibility to improve the geometry of the strips. Modified steel strips can be deeply investigated in simulations and subsequently verified by push-out tests in laboratories. The combination of these two methods can bring the spectrum of the information that can complexly describe the behaviour, durability and also the weak points of the shear connection, especially in case of the new or modified shape.

NUMERICAL ANALYSIS AND EVALUATION OF EFFECTIVE SLAB WIDTH OF COMPOSITE CONTINUOUS BEAMS WITH SEMI-RIGID JOINT

The characterization of the structural behavior of composite beams is directly affected by the determination of the effective slab width. Various codes propose their own definitions of the effective width based on the beam span and the slab width parameters. However, the evaluation of the effective width may be influenced by other parameters. The aim of this work is to determine the most important factors affecting effective width for continuous composite beams with semi-rigid joints using numerical simulations. A three-dimensional finite element model of a composite continuous beam using explicit-solver available in ABAQUS is developed. The proposed model is validated through comparisons to available experimental results. A modified model is proposed based on the so-validated model to study the influence of the composite beam-column joint stiffness on the effective width. Then, both numerical models are used to perform an extensive parametric study to investigate the influence of various parameters on the estimation of the effective slab width. The influence of slab width, the shear connection degree, and composite joint stiffness are particularly analyzed to find out the most important parameters influencing the effective width so that simplified equations for the calculation of the effective slab width are proposed.

REVIEW OF VARIOUS SHEAR CONNECTORS IN COMPOSITE STRUCTURES

Shear connectors are devices that provide shear connection at the interface of steel girders and reinforced concrete slabs in composite structures to accomplish composite action in a flexure. The seismic response of composite structures can be controlled using properly designed shear connectors. This state-of-the-art review article presents considerable information about the distinct types of shear connectors employed in composite structures. Various types of shear connectors, their uniqueness and characteristics, testing methods and findings obtained during the last decade are reviewed. The literature, efficacy, and applicability of the different categories of shear connectors, for example, headed studs, perfobond ribs, fibre reinforced polymer perfobonds, channels, pipes, Hilti X-HVB, composite dowels, demountable bolted shear connectors, and shear connectors in composite column are thoroughly studied. The conclusions made provide a response to the flow of the use of shear connectors for their behaviours, strength, and stiffness to achieve composite action.