Analysis of EHB Joints to Concrete‐filled Steel Columns: Combined Failure in Tension

Structural hollow sections are popular in the building industry as they offer many structural, economical and architectural advantages over other sections. However, their use is limited due to the difficulties in performing site bolting connections using standard bolts. Blind-bolted systems were developed to overcome this limitation as they only require access to one side of the hollow section to tighten the bolt. This paper reviews the available information in the literature regarding the combined failure mode of the Extended Hollo-Bolt (EHB) blind fastener. The assessment of the effects of bolt grade on the behaviour of the tension zone of the connection is also presented. A Finite Element (FE) model was developed, validated and used in a parametric study. It is concluded that the use of a higher bolt grade has clear effect on the component global load-displacement curve and the failure mode. The failure of the connection is first controlled by the plastic resistance of the component, which is limited by concrete crushing accompanied with hollow section yielding. Then it depends on the strength of the bolt. An experimental test setup and variable ranges for the parameters affecting the connection behaviour in tension are proposed.