Exterior RC Wide Beam-Column Connections: Effect of Spandrel Beam on Seismic Behavior

摘要

This paper presents the results of a set of experiments performed on four large-scale exterior wide beam-column connections. The beam and column geometry and reinforcement detailing are identical for all four specimens, but the spandrel beam sizes and reinforcement ratios are different in each specimen. The specimens are tested under a combination of a constant axial force and quasi-static reversed cyclic lateral displacements. Detailed strain measurements, crack patterns, and data analysis indicate that the strength and stiffness of the spandrel beams could significantly change the expected response of wide beam-column connections. According to the results of the tests, the specimen with no reinforcement in its spandrel beam failed in brittle torsion with a significant reduction of strength and ductility compared to the expected capacities of the connection. Comparison of the test results indicates that the joint shear capacity of the specimen having a conventional deep spandrel beam did not significantly improve over the same specimen having a shallow spandrel beam. However, the results confirm that a well-reinforced wide spandrel beam substantially enhances both the joint shear capacity and the spandrel beam torsional strength of the connection. Design proposals, accounting for the joint shear and spandrel beam torsion, are recommended.