Behavior of High-Strength Friction-Grip Bolted Shear Connectors in Sustainable Composite Beams

Abstract

Composite beams comprised of concrete slabs and steel beams joined by mechanical shear connectors are commonly used in modern building design. The use of innovative deconstructable high-strength friction-grip bolt (HSFGB) shear connectors and reduced-emissions precast geopolymer concrete slabs in composite beam design can greatly enhance the sustainability of building infrastructure. Hitherto, research contributions that address the behavior of composite beams with HSFGB shear connectors and precast geopolymer concrete slabs are very limited. To provide a contribution to this area of research, an effective finite element model of push-out testing is developed to investigate the ultimate strength and the load-slip characteristics of shear connection using HSFGB connectors and geopolymer concrete slabs in this proposed sustainable composite beam application. The accuracy of the proposed finite element model is validated by comparing its predictions with experimental results on push-out test specimens also reported in the paper. The effects of the change in the bolt pretension, its clearance between the hole in the steel flange, its diameter and tensile strength,and the compressive strength of the geopolymer concrete are elucidated through parametric studies. Practical design recommendations in algebraic form are proposed and verified for predicting the ultimate strengths and the load-slip relationships for composite beams with HSFGB shear connectors.