C-13.113.1 general

The double-tee provisions were written primarily based on testing performed at the Georgia Institute of Technology. The series of six connection tests used a W14×145 (W360×216) column and either a W21×44 (W530×66) or W24×55 (W610×82) beam (Swanson, 1999). The tests are summarized in Table C-13.1. This series of six full-scale assembly tests was supplemented by a series of 48 tests on T-stub components conducted at the Georgia Institute of Technology (Swanson, 1999; Swanson and Leon, 2000). None of the tested configurations included a concrete slab, and all of the tested configurations included a single-plate shear connection between the web of the beam and the column flange.

Research work conducted at the University of Wyoming (McManus and Pucket, 2010) was also considered in development of these double-tee provisions. Testing associated with this program included 22 T-stub component tests with very wide gages between the two rows of bolts connecting the T-flange to the column flange and T-stubs with very thick shims between the T-flange and column flange. These shims were arranged to provide a gap between the T-flange and column flange such that inelastic bending of the T-flange could occur not only when the T-stub was subjected to tension, but also when it was subjected to compression.

Research conducted at the University of Cincinnati on T-stubs built-up from thicker plates was also considered in the development of these provisions (Hantouche et al., 2013; Hantouche et al., 2015). The intent of this work was to allow for the use of built-up T-stub components in the double-tee connections. However, because the testing that was performed at the University of Cincinnati did not include full-scale assemblies, the CPRP elected to not permit built-up T-stubs in this edition of the provisions.

A series of five full-scale beam-column subassemblies was tested at the University of Texas at Austin in 1996 (Ulloa Barbaran, 1996; Larson, 1996). These assemblies consisted of cantilever W36×150 (W920×223) beams connected to pinned-pinned W14×426 (W360×634) columns using a single-plate shear connection to resist shear and, in most cases, fully bolted T-stubs to resist moment. The first specimen was designed with a shear-only connection—with a single-plate shear connection but without T-stubs—to investigate the contribution of the single-plate shear connection and beam web to the moment strength of the connection. The second and third specimens were designed both with a single-plate shear connection and T-stubs, but the T-stubs were configured to provide only a partial strength beam connection. The fourth and fifth specimens were designed with both a single-plate shear connection and T-stubs with the tees in the fourth specimen proportioned to transmit 100% of

• Column was stiffened with continuity and doubler plates.

the beam moment to the column and the tees in the fifth specimen proportioned to transmit approximately 125% of the beam’s plastic moment (Ulloa Barbaran, 1996). The connections were loaded by applying a displacement to the end of the cantilever beam. The fourth and fifth specimens are most germane to the topic of prequailification of double-tee connections. The fourth specimen failed when the bolts connecting the T-stubs to the column flange fractured. After disassembling the connection, small fractures near the bolt holes in the flange of the beam were noted. Testing of the fifth specimen was stopped when a fracture of the beam flange was noticed. None of the specimens performed adequately to be considered for use in SMF or IMF systems.

Research on bolted flange plate (BFP) connections conducted at the University of Illinois (Schneider and Teeraparbwong, 1999) and at the University of California at San Diego (Sato et al., 2008) was also considered because the connection of the flange plate to the beam flange in a BFP connection is nearly identical to the connection of the T-stem to the beam flange in a double-tee connection.