A review and analysis of testing and modeling practice of extended Hollo-Bolt blind bolt connections

Steel Hollow Sections (SHS) offer many structural, economical and architectural advantages in multi-storey and high-rise construction. However, their use is not suitable for a wide range of applications due to the difficulties of site bolting as there is limited access to the inner part of the steel section for tightening of standard bolts. Blind bolts have been developed to overcome these difficulties in view of extending the application of SHS in construction. Special attention has been paid to blind bolts that could potentially be used in rigid or semi-rigid connections. This is the case of a modified blind bolt, termed the Extended Hollo-Bolt (EHB), which has shown to be able to achieve the required performance for its use in moment resisting connections. This paper critically reviews published work concerning the blind fastener, describes the loading procedures used for testing and failure modes produced, lists the assessed parameters with their respective applicability ranges, and summarises the analytical models developed for the EHB components. Additionally, a global sensitivity analysis is performed using information of two representative studies for the purpose of detecting key design parameters that influence the response of the connection in terms of strength and stiffness. The analysis shows that the concrete strength has the most influential effect on both the stiffness and strength of the column component as well as bolt component stiffness, while the bolt grade highly influences the bolt component strength.