Performance of hollowcore floor seating connection details

Abstract

Hollowcore floor slabs are the dominant flooring systems used in New Zealand since the 1980’s.  This study examines the performance of three different types of beam to hollowcore floor slab seating connection detail under seismic loading conditions.  Two of these connection details tested are used in present New Zealand practice and the other is a potential retrofit detail to construction practice of the 1980’s and 1990’s.

In this sub-assemblage research, relative rotation between the supporting beam and hollowcore floor is used as the dominant source of damage instead of the traditional pull and push approach.  The sub-assemblages were tested up to inter-storey drifts of ±4.0% and visual and instrumental observations from the experiments are outlined.  An analytical study is conducted to better understand the observed failure modes and strength capacity for each seating connection details is also predicted.   Finally, fragility analysis is used to determine the seismic vulnerability for all three types of connection detail.  Results show that hollowcore units should have some reinforcing in their cells.  However, the cells should not be over reinforced as this becomes detrimental to performance.