Performance and Characterization of Shear Ties for Use in Insulated Precast Concrete Sandwich Wall Panels

摘要

Insulated precast concrete sandwich wall panels are commonly used for exterior cladding on building structures. The insulation is sandwiched between exterior and interior concrete layers to reduce the heating and cooling costs for the structure. The panels can be designed as composite, partially composite, or non-composite. Shear ties are used to achieve these varying degrees of composite action between the interior and exterior concrete layers. A variety of shear ties are available for domestic construction. An experimental study was conducted to assess the relative strength and response of these commercially available ties. Fourteen shear ties were examined, the failure modes and responses were quantified, and simplified engineer level multi-linear strength curves were developed for each connection. The results indicate that shear ties used in sandwich wall panels have considerable variation in strength, stiffness, and deformability. The maximum shear strength of the discrete ties averaged 10.5 kN (2357 lb) with a minimum of 5.52 kN (1241 lb) and maximum of 18.4 kN (4138 lb). The ties exhibited elastic-brittle, elastic-plastic, plastic-hardening, and a variety of other responses. The results were used to develop tri-linear constitutive relationships, which were used to approximate the flexural response of sandwich wall panels.