Timber-Cardboard Web-Core Sandwich panels for lightweight housing applications

Timber-Cardboard Sandwich (TCS) panels are an innovative bio-based structural system consisting of thin timber facings bonded to a monolithic corrugated cardboard core. This paper introduces a modified version, the Timber-Cardboard Web-Core Sandwich (TCWS) panel, which replaces the continuous core with a spaced arrangement of cardboard ‘studs’, to significantly reduce panel density while preserving weight-specific structural performance. Experimental and numerical studies were conducted on TCWS wall panels with varied core spacings loaded under eccentric axial compression. Four tested specimen types all had a length of 2400 mm and widths from 400 mm to 700 mm, with corresponding core spacing intervals from 300 mm to 600 mm. Failure mode progression and face elastic and plastic buckling behaviours are fully characterised, enabling the accurate prediction of panel linear and nonlinear response histories. Results show that TCWS panels achieve nearly a 50% reduction in density compared to traditional TCS panels while maintaining equivalent weight-specific structural performance. Additionally, TCWS panels demonstrate up to 33% higher strength than comparable foam-core and bio-based sandwich panels at similar densities. These findings show that TCWS panels enable lighter and more cost-effective sandwich panel wall solutions and support the broader use of cardboard in sustainable building products. • Timber-cardboard sandwich structure designed for lightweight and low-cost wall panels. • Non-monolithic web-core minimises material use, reducing weight and overall cost. • Panels show high weight-specific strength compared to conventional panels. • Numerical models accurately predict structural response as influenced by core web spacing.