An experimental study of the behaviour of sleeved bolt connections in precast concrete frames

Sleeved bolt beam-to-column connections have been used in the precast concrete industry for many years. They have advantages over other jointing methods in component production, quality control, transportation and assembly. However, there is at present limited information concerning their detailed structural behaviour under shear loading. The study reported in this paper was undertaken to elucidate the behaviour of such joints under symmetrical vertical loading. Two series of full-scale tests were preformed on sample columns for which the column geometry and bolt arrangements conformed with successful commercial practice. The first series of tests was used to investigate the influence of bolt density on the ultimate load, failure mode and stiffness of such connections. The second test series showed the influence of varying concrete strength and the effectiveness of the confining reinforcement. Full details of these test programmes are given. The finite element modelling technique was used to develop three-dimensional models which were calibrated against the test observations. These models subsequently provided complete stress and deformation distributions within the joint components at intervals up to the ultimate load, and are the subject of another paper.