Timber‐Earth – Structural Behaviour of a Composite Material for Horizontal Building Elements

Abstract Timber‐earth hybrid systems for horizontally spanning structural elements offer a sustainable, circular‐oriented solution with additional benefits related to sound insulation, fire resistance, and thermal mass. By leveraging the ecological advantages of earthen construction ‐ such as low embodied emissions and material reusability ‐ these systems present a viable alternative to conventional methods and contribute to a reduced environmental impact in the construction sector. This paper focuses on integrating earth as a load‐bearing component to ensure effective load distribution between timber and earth. A key challenge in bending‐stressed timber‐earth systems is achieving efficient shear force transfer for reliable structural performance. To address this, a series of push‐out tests were carried out, drawing on established approaches from timber‐concrete composite research. The scalability of the resulting shear connection properties was then examined through tests on full‐scale (1:1) components employing various shear connector types. For an initial numerical and computational assessment, commonly used design methods from timber‐concrete composite systems ‐ such as the γ‐method and the truss model method ‐ were employed.