Experimenting with Cardboard Formwork for Precast Concrete Building Components

In this study, we investigated the use of corrugated cardboard as a resource for making molds for precast concrete components, aiming to expand the application of cardboard in concrete casting. Three prototypical formwork applications were developed and analyzed - small blocks for green walls, modular twisted blocks for columns, and modular steps. We present a set of design criteria for the fabrication, and a cost-effective technique for waterproofing the molds to maintain their reusability and recyclability. The study demonstrates the feasibility and benefits of using cardboard molds for concrete casting, but also identifies challenges, such as achieving geometric precision, the surface finishing quality, and limitations on the size and weight of the cast elements due to the cardboard's limited strength during extended curing periods. The study highlights how the intended application influenced the developed fabrication workflow. Future work will address these challenges and assess the environmental impact of this method, laying the groundwork for further refinement of this alternative approach to promoting more-efficient building practices.