Push–out Experiments of Headed Shear Studs in Group Arrangements

Abstract

Precast concrete slabs connected to the steel beams by headed shear studs arranged in groups may be used in high-rise office buildings to speed up construction process and improve quality by increasing the grade of industrialization. The paper presents experimental research performed on push-out tests at the Faculty of Civil Engineering University in Belgrade. The main goal has been to investigate possible reductions (if any) of shear stiffness and strength of five group arrangements consisting always of four headed shear studs, the shank diameter 16 mm and 100 mm height. A shape of group arrangement and its orientation to the applied load, and distance between the studs were variables considered. Intention was to have as small as possible holes in precast concrete slabs so the distance between studs was lower than minimum required in Eurocode 4 [1]. Comparison is made with results obtained on specimen with uniformly distributed shear studs, according to requirements of the standard arrangement [1]. Material characteristics were obtained and push-out tests were preformed in procedures that fully comply with Eurocode 4.Experimental results were evaluated according to the design models in Eurocode 4 and available literature, Okada-Yoda-Lebet [2]. Recommendations for use of the group arrangements were proposed.

Shear connection with groups of headed studs

“…Specimens G1 and GR1 were prepared with the same arrangement of headed studs, but with different types of prefabricated slabs. Specimens GR1 had the reinforcement bars immediately in front of the headed studs, which is at the same time used for connecting the prefabricated slab and the infill concrete, while in the case of G1 specimens, the reinforcement bars do not exist [10]. The same results for the ultimate shear resistance and the ductility at ultimate load were obtained for specimens G1 and GR1.…”

“…Experimental results obtained by push-out testing are thoroughly analysed in the study conducted by Spremic et al [10]. Essential findings from the above study are presented in this paper.…”

Load Transferring Mechanism of Flexible Shear Connectors

“…Milan Spremic et al (2013) [4] investigate the possible reductions of shear stiffness and strength of five group arrangement all consisting of 4 headed studs. Their intention was to have as small as possible holes in precast concrete slabs so the distance between studs was lower than the minimum required in Eurocode.…”

08.49: Comparison of headed studs with perfobond shear connectors – experimental and numerical analysis

“…According to recommendations given in EN1994-1-1 [4], when slip to failure δu is higher than 6 mm, shear connector can be considered as ductile. Force-slip curves for headed studs [3] and perfobond shear connectors [1] Characteristic design shear resistance of whole LDA1c specimen with eight headed studs, according to EN1994-1-1 [4] determined for experimentally obtained material properties of concrete and headed stud is determined with Eq. 4 headed stud with 16 mm diameter can be considered as ductile.…”

“…In order to industrialise the construction process as much as possible the amount of concrete necessary for the grouting of prefabricated slabs needs to be minimised. In order to downsize the holes for studs in prefabricated slab, authors in [3] explored reducing the spacing between headed studs within the group compared to EN1994-1-1 requirements [4]. Grouting of the slabs is done through concrete filling of the space between two prefabricated slabs and parts of the structure where connectors are located.…”