Experimental behaviour of a novel anchored blind-bolt in tension

Current state-of-the-art models for steel and composite joints are based on the so-called component method. These models require knowledge of the behaviour of the relevant joint components, and also require an appropriate assembly procedure. Within the framework of the component method, this paper presents the results of an experimental programme for a novel blind-bolt component, whose application relates to the construction of moment-resisting joints between open profile beams and concrete-filled hollow section columns. The aim of the programme was to quantify the component’s level of pre-load, and to measure its full, non-linear force–displacement response. The latter was determined by monotonic pull-out tests. A total of 51 pull-out and 20 pre-load tests are reported. The test variables were the grade (or property class) and size of the internal bolt, the strength of the concrete infill, and the embedded depth. The load transfer mechanism of the component was investigated on the basis of the individual elements which contribute to its overall deformability; namely, the elongation of its internal bolt, and the slip of its expanding sleeves and mechanical anchorage elements. For the studied range, the test results demonstrate that the anchored blind-bolt component can ultimately provide resistance to pull-out, achieving the full tensile capacity of its internal bolt. This failure mode is comparable with that exhibited by standard bolts, illustrating the suitability of the component in resisting the predominant tensile loads expected in moment-resisting construction. Increasing the compressive strength of the concrete infill had the most enhancing effect on the tensile stiffness of the component.