Digital Design and Fabrication Strategy of a Hybrid Timber-Earth Floor Slab

The production of floor slabs with their high requirements for fire protection, thermal mass, and sound insulation is a central challenge in multi-storey timber construction. The research presented in this paper explores the possibilities of a timber-earth slab (T.E.S.) that can meet such high demands while being fully recyclable. T.E.S. comprises a hybrid structure, which aims to combine the strong tensile properties of wood with the beneficial properties of earth in terms of thermal mass, thermal activation capabilities, fire resistance, and sound insulation. It integrates a novel material technology capable of casting earth with low water content and combines it with robotic technology that enables the bespoke fabrication of a filigree wooden structure tailored to mechanically interlock with the earth infill. The proposed method makes it possible to place the earth infill in the lower part of the floor slab and thus expose it to the interior space, whereby its storage mass and component activation can be fully utilized. This paper presents the concept and design principles, initial findings on the system's loadbearing behaviour, as well as the experimental validation of the novel fabrication process in 1:4 and 1:1-scale demonstrators, in which the general feasibility of the system in assessed. The paper finally discusses the proposed methods and results of the experiments and outlines further steps for transferring the system into building practice.