Plug and play type joints in steel and steel-concrete composite constructions

Traditionally for Western Europe countries, joints in steel frame structures are realised using bolts and welds. In the workshop the components are made using welding and drilling of the bolt holes. On site these structural components are connected together using bolts and nuts. The actions on site means a large physical effort of the steel construction workers and is not free from danger. Measures that need to be taken to ease the work and to make it safe for the workers are increasingly expensive. Furthermore the availability of skilled workers who want to do these jobs under variable climatic conditions is decreasing. So the question arises whether there are possibilities to invent so called "plug and play" connections which can be realised using remote control techniques. An extreme example is the connecting device used to dock an space shuttle to a space station. For the average steel structure we are still far away from that situation and we can do with more simple solutions but even those simple plug and play connections are so far only very limited available. Examples of non-traditional types of joints are used in Slim Floor construction. In this type of flooring, the steel beams are integrated into a prefabricated concrete hollow core slab or a deep deck composite slab. The so called plug and play beam to column joints in these mixed structures are characterised by simplicity and fast erection methods. These joints could also be used in traditional steel-concrete composite flooring systems. Most often these joints are only intended to act as a hinge. However, there are some ideas to make plug and play type joints that also can resist some bending moment even in construction stage. As holds for traditional connections also these plug and play joints should resist the forces and moments resulting from all types of loading related to the use of the structure and resulting from the natural circumstances such as wind and snow. For these type of joints no specific design rules are available in Eurocode 3, Part 1.8: 'Steel joints' or chapter 9 of Eurocode 4, Part 1.1: 'Composite joints'. The paper describes the basis of design for these joints. Design requirements will be drafted. Some considerations are given to optimise the joint with respect to overall structural behaviour from a technical and economical point of view. The costs of fabrication may slightly be higher than the costs of traditional joints provided that the total costs of fabrication and construction decrease. Fast and safe construction methods with plug and play joints are required for the future.