Sustainable raw-earth blocks achieved with 3D-printed formworks: parametric modeling, prototyping, and laboratory testing

The demand for green construction requires a fundamental shift in construction techniques and materials to prioritize sustainability. In this context, the present work introduces a modular building block crafted from raw-earth using innovative and accessible 3D-printed formworks. Achieving such a goal requires (i) creating a parametric model, (ii) producing the 3D-printed prototypes, and (iii) conducting laboratory tests to prove the performance of the component. The prototype is applied in central Italy using materials from Chieti province, specifically Casalincontrada, where earthen architecture has been used for centuries. The combined parametric model and iterative testing enable the creation of a flexible, effective block for building components and furnishings. The results confirm the feasibility of constructing raw-earth blocks using 3D-printed formworks. Indeed, an efficient material configuration is identified as Gravel 5.5%, Sand 19.4%, Silt 46.1%, and Clay 29.0%, demonstrating an effective compression strength of 3.4 MPa ± 0.25 MPa sufficient to achieve a performing block.