3D Printed Earth Formworks for Concrete (2024-09)¶

This paper presents a novel production concept for casting of material efficient concrete slabs using circular 3D printed earth formworks. While optimized concrete structures exist, their complexity often leads to high waste generation due to single-use forms. Other less known, localized techniques such as clay-filler slabs, popularized in India, successfully reduce concrete consumption by 50% by employing locally crafted pottery as a stay-in-place formwork. Although effective, these analogue methods remain constrained in terms of design flexibility and circularity. This study consequently leverages the sustainability potentials of the clay-filler slab— It transforms the technique into a new method for making 3D printed formworks from local earth materials, creating efficient and customizable concrete slabs. This process reduces emissions, improves material efficiency, and expands design options through digital fabrication, promoting circularity. The study investigates material and processing methods for earthen formworks using a slab design initially made in polymer filament. The design is subsequently scaled up into three demonstrators using a customized earth mix, addressing challenges in scalability for real-world construction. Covering the entire process from design to fabrication, it emphasizes digital workflows and tools, showcasing advancements in printing and casting mixtures. Lastly, it discusses the potential for material savings and circularity through digital processes, addresses current limitations, and outlines future development steps.