Shear performance of X and Z configuration wythe ties for insulated precast concrete sandwich panels using different FRP materials

This study investigates Insulated Precast Concrete Sandwich Panels (PCSP), a versatile system integrating structural and thermal efficiencies suitable for diverse structures. PCSP's structural behavior depends on effective shear force transfer between two wythes through components known as "Wythe Ties." Testing twelve push-off specimens explores angled connectors with various FRP-composite Wythe Tie configurations to assess stiffness in PCSP design. Serving as the second phase of experimental work after prior findings' publication, the research compares Steel, Carbon, and Basalt FRP wythe tie behaviors, analyzing key factors' influence on strength, stiffness, and deformability. Evaluation includes performance assessments of shear strength, relative slip, stiffness, and failure modes. To validate, a nonlinear 3D-FE analysis simulates tested specimens' behavior, revealing a fitting progressive failure pattern and demonstrate good agreement with experimental results. The study unveils significant shear tie variations in PCSPs, where type and configuration impact ultimate capacity, stiffness, and toughness of wythe ties. Notably, Notably, for X-configuration shear ties, steel and CFRP-bar shear ties were observed to be the most effective material types. On the other hand, for Z-configuration shear ties, CFRP-Strip and CFRP-bar shear ties were identified as the most effective material types. Overall, these insights guide designers in choosing suitable wythe tie configurations and materials for specific PCSP applications.