Investigation of a novel composite cladding wall panel in flexure

A composite panel consisting of polyurethane foam core sandwiched between two carbon fiber-reinforced polymer (CFRP) skins is investigated in one-way bending. While most studies on sandwich panels are typically geared towards aerospace applications, to the authors' knowledge, this is the first study on application in cladding of buildings. Ten panels were tested to investigate their structural performance and failure modes. Test parameters include consistency of quality and performance, moment-shear ratio, moisture absorption and orientation of architectural masonry-like coating. The panels were 14 times lighter than conventional reinforced concrete panels of equivalent strength and stiffness. The study showed that design is stiffness driven as deflection limits in service will likely govern. Shear deformations of core may have a significant contribution to deflections. Most common failure mode was outward buckling of CFRP skin. Some panels failed by shear in the foam core, and in one panel, CFRP skin crushed. When the masonry-like coating was positioned in compression, it forced a shear failure but when located in tension to simulate wind suction, skin buckling occurred at lower load. While this study showed excellent potential for this novel cladding, it is recommended to laminate FRP layers to prefabricated solid foam cores, rather than injecting liquid foam in between FRP skins, to improve quality control during fabrication.