Anchored blind bolted connections within SHS concrete filled columns: group performance

Concrete filled tubes are suitable choices for columns of low to medium rise commercial buildings. However, lack of access to the inner surface of these sections prevents connections with conventional bolts. To overcome this problem, blind bolts that can be installed only from one side can be used. A new type of blind bolt, the headed stud anchored blind bolt, has been developed at the University of Melbourne in collaboration with Ajax Fasteners. This type of blind bolt, in addition to bearing on the tube wall, is anchored in the infill concrete which results in improved stiffness and strength when it is subjected to tensile force. The pull-out behaviour and strength of headed stud anchored blind bolts as individuals or groups of two and three are studied in this research. The study shows that the tension connections made using groups of blind bolts potentially have sufficed strength and stiffness to be used in moment resisting connections within low to medium rise buildings in low to moderate seismic areas such as Australia.