Push-out experiments of headed shear studs in group arrangements

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.