Pull-Out Performance of Eccentrically Spliced Longitudinal Headed Bars for Precast Beam-Footing Connections

Abstract

For common detailing of footings in steel or precast concrete structures, longitudinal reinforcement of foundation beams is bent horizontally and spliced with reinforcement of cast-in-place footings to insure an adequate juncture for load transfer. In this study, instead of bending longitudinal reinforcement bars of both, beams, and footings, headed reinforcement bars are adopted. By doing so, a discontinuity region is created where longitudinal bars of footings become eccentric to those of beams that are embedded in the footings. To allow developing forces in longitudinal bars of beams flow to longitudinal bars of footings, a set of reinforcing ties is provided between them. As such setting of headed reinforcement bars is not common, thorough investigations have been carried out. In this paper, the pull-out performance of eccentrically spliced longitudinal headed bars with different detailing of transverse reinforcement, proposed for precast beam-cast-in-place footing connection, is discussed based on an experimental investigation. A method, based on the friction shear theory, for the strength evaluation of such arrangement is suggested.