Axial compressive experiments and structural behaviour estimation of CFS composite walls sprayed with LPM

Introduction of filling materials, such as lightweight polymer material (LPM), is very beneficial for traditional cold formed steel (CFS) walls. A further improvement of CFS walls via introducing LPM is that it is expected to enhance the sound insulation property and thermal insulation. In order to explore the compressive behaviour and bearing capacity of CFS composite walls sprayed with LPM, five full-scale specimens were tested under axial compression loading. Furthermore, effects of infilled material type and sheathing type on the axial compressive response of this type of CFS composite wall were explored. Failure modes, axial force-displacement relationships, axial load-strain responses, axial bearing capacities and ductility indexes of the test specimens were also studied and estimated. The tests showed that the wall studs, infilled material and wall sheathing together resisted the axial compression. Clear evidences were obtained that the axial bearing capacity and axial compressive stiffness of CFS composite wall sprayed with cement-based LPM were significantly higher than those sprayed with gypsum-based LPM. Wall sheathing can improve the axial compressive behaviour of composite walls. Additionally, a formula for predicting the axial bearing capacity of CFS composite wall sprayed with LPM was put forward and verified by the test data. The experimental and analytical results can promote the design and application of CFS composite walls sprayed with LPM in low- or mid-rise.