Behavior and design of a new gravity-type precast beam-to-girder joint integrating bearing and shear-friction mechanisms
Journal
Journal of Building Engineering
Journal Volume
119
Start Page
115167
ISSN
23527102
Date Issued
2026-02-01
Author(s)
Abstract
This study proposes a novel precast beam–to–girder connection system that integrates a steel shear connector with a bearing plate to enhance constructability and ensure joint strength under gravity loading. Eight full-scale specimens were tested in two experimental series. The first series focused on bearing behavior with varying plate sizes, while the second examined the completed connection, considering beam cross-sectional shape, top longitudinal reinforcement ratio, and stirrup configuration. Experimental results showed that failure consistently occurred at the beam–girder interface through combined bearing and shear-friction mechanisms. The maximum bearing capacity was conservatively estimated using a refined design equation derived from ACI 318-19 and modified to account for partial confinement, with experiment-to-prediction ratios ranging from 1.47 to 3.69. Strain data confirmed that the top longitudinal reinforcement of the beam and slab functioned as shear-friction reinforcement; however, the contribution of beam reinforcement was limited by top cover spalling. Simplified joint strength models combining bearing capacity, shear friction, and slab shear provided consistently conservative predictions of ultimate strength, with average ratios between 1.88 and 2.63 depending on the friction coefficient. These findings validate the feasibility of the proposed connection and provide practical design recommendations, including limits on reinforcement stress and area, to improve the reliability of precast concrete systems.
Subjects
Beam-to-girder connections
Bearing plate
Precast concrete
Shear connector
Shear friction
Publisher
Elsevier Ltd
Type
journal article