Shear Behavior of Screw Connection between Cold-Formed Steel and Gypsum Sheathing at Elevated Temperatures

The screw connections between cold-formed steel (CFS) and gypsum sheathing play an important role in the axial and lateral performance of CFS wall panels. Previous researches were mainly focus on the shear behavior of such screw connections at room temperature. This paper carried out a preliminary experimental investigation on the mechanical performance of screw connections with single layer gypsum sheathing at elevated temperatures. Limited to the cavity dimension of the furnace, the single-lap test of CFS coupon -fastener-sheathing connection was adopted and compared with the previous test results of sheathing-to-profile screw connections at room temperature. The failure of screw connections with single layer gypsum sheathing was identified as the breaking of the sheathing edge at elevated temperatures and a sharp decrease of the shear strength was observed beyond 150 °C. In addition, the load-displacement curves of screw connections were well predicted by an exponential model with the post-peak branch at elevated temperatures