Axial compression tests of grouted connections in jacket and monopile offshore wind turbine structures

•Seven cylindrical grouted connection specimens with shear keys were designed and tested.•Two specimens represented jacket structures were tested by pure compression.•The other five ones represented monopile structures were axially compressed after two million bending cycles.•The five monopile residual specimens had competent residual axial compression capacities.•The FE models for specimens could reflected the failure mode, maximum capacities and the strain distributions.