Use of adhesives to increase the load-bearing capacity of slip-resistant connections.

Slip-resistant connections are preferred for steel constructions if subjected to fatigue loads and/or load reversals, no slip in the connection is permitted and joining on construction site is necessary. These connections are pre-pared with a high manufacturing effort due to the intensive preparation of the faying surfaces, or the contact area between the steel plies and it must receive special consideration in design and coating application. The typical corrosion protection for steel structures is still the hot-dip galvanizing. The follow-up work of the faying surfaces for a use in slip-resistant connections is related to a high effort and guarantees no high slip factors. Furthermore the slip factor may deviate more or less high with the properties of the zinc layer. Against this background, investigations have been carried out in a recently concluded research project which show an increase in the load bearing capacity of slip-resistant connections by the combined use of adhesive. In the case of the process combination, which is also referred and named as a preloaded hybrid connection, the applied preload of the highstrength bolts is responsible for the considerable increase in load bearing capacity compared to the elementary joining processes adhesive bonding or just slip-resistant connections. If the two methods are carefully combined, the individual load bearing -capacities can approximately add up.