Performance of cold-formed-steel-framed shear walls sprayed with lightweight mortar under reversed cyclic loading

• Sheathing of CFS-framed shear walls by spraying of lightweight mortar is proposed.
• Sheathed CFS-framed shear walls were tested under cyclic loading.
• Sheathing on both sides significantly increases walls’ strength and stiffness.
• The failure modes of sheathed wall specimens were observed.
• Slippage between the frame and sheathing enhances ductility and energy absorption.

Sheathing with sprayed lightweight mortar (SLM) is proposed to enhance the performance of shear walls framed with cold-formed steel (CFS). Full-scale specimens were tested to assess the failure mode, strength, stiffness, ductility, and energy absorption achieved. Slippage between the CFS framing and the SLM significantly increased the walls’ strength and stiffness and restricted crack propagation. The failure mode typically involves local buckling of the end studs. Specimens with SLM on the front and calcium silicate boards (CSBs) on the back were weaker than specimens with SLM sheathing on both sides. Joint-strengthened knee elements or X-shaped steel-strap bracings increased the load-bearing capacity and reduced the ductility of the specimens.