An efficient structural system for tall building construction to resist earthquake loads consists of reinforced concrete shear walls connected by diagonally reinforced coupling beams. Construction of coupling beams that satisfy the strength and detailing requirements set forth in ACI 318-05 for diagonally reinforced coupling beams is cumbersome and costly; therefore, ACI 318-08 provides a new detailing option which aims to improve the constructability while maintaining adequate strength and ductility. Seven half-scale specimens were tested to compare the performance of beams constructed utilizing new and old detailing options, to evaluate common modeling approaches, and to assess the impact of reinforced and post-tensioned slabs on the load-deformation response of the beam. Test results indicate that the new detailing approach provides equal, if not improved behavior as compared to the alternative detailing approach, that simple modeling approaches reasonably capture measured force versus deformation behavior, and that including a slab had only a modest impact on strength, stiffness, ductility, and observed damage.
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