Composite slab construction is gaining popularity in New Zealand. These slabs may influence the beam column joint subassemblies as they exposed to earthquake induced shaking. However several design issues with composite slabs need to be addressed so that they can be used to their full advantage in design. These relate to the ability to consider the slab effect on the beam design strength, the likely statistical variation of beam and slab under strong seismic shocks that will affect the column joint demand and the resistance of the panel zone. In this paper, the experimental test setups are described which considers slab isolation, beam overstrength, full depth slab around the column, low damage connection, and demand on the panel zone. A new concept of slab confinement using a shear key will be presented to form a force transfer mechanism to avoid failure of concrete either in crushing or spalling. Also the development of a non-prying sliding hinge joint low damage connection and its performance under composite slab is discussed. The outcome of this will be useful to develop simple design recommendations for the New Zealand steel standard.