Non-preloaded and preloaded connections with injection bolts - Experimental and numerical investigations

Slip-resistant connections can be realized with fitted bolts, high strength friction grip bolts and injection bolts. By filling the clearance of the bolt with curing resin, injection bolts offer advantages in terms of execution and design. Normative requirements for the design and execution of injection bolts are essentially available in EN 1993-1-8, EN 1993-1-9 and EN 1090-2. Various factors influencing the load-deformation behaviour of non-preloaded and preloaded injection bolts were investigated within the presented research project to complement these regulations. The epoxy resins Rengel, Biresin and MM1018 showed promising bearing resistances and were determined as suitable resins for the application in connections with injection bolts. Boundary conditions close to reality – such as thermal extremes, humidity and long-term effects – led to no significant reduction of the bearing capacity. The interaction between the bearing of the resin and friction in the case of a preloaded application was considered in experimental and numerical investigations. In addition, fatigue failure of the resin could be precluded and the given detail categories confirmed independently of the resin.