Eccentric compression behaviour of hybrid timber-cardboard sandwich columns

Abstract

Timber-Cardboard Sandwich (TCS) panels are an emerging class of lightweight and low cost structural composite material, made from bio-based and recycled waste materials. However, there is a lack of data and knowledge as to their compressive behaviours, preventing their structural application as column or wall panel elements. This paper conducts experimental and analytical investigations to address this knowledge gap by characterising the eccentric axial performance of TCS columns. Thirty columns were tested under uniaxial compressive loading, with specimen types developed to investigate the influence of four key design parameters: cardboard core source material, the type and thickness of timber facings, and column slenderness ratio. Test results indicate that the face crushing governing failure mechanism and column ultimate capacity were primarily controlled by the timber facing material, with no observable influence of failure contributions from the cardboard core. Based on experimental observations, analytical models were developed to predict load-carrying capacity and lateral deflection for eccentrically-loaded TCS columns, giving ultimate load predictions within 5% for all studied column types. Research findings provide valuable insights that will enable cardboard to be more widely used in sustainable composite building products.