Evolutionary Approach Based on Thermoplastic Bio-Based Building Material for 3D Printing Applications: An Insight into a Mix of Clay and Wax

Abstract

Digital manufacturing technique is becoming one of the most promising ways to automate construction. While applications of 3D printed concrete daily increase, those of bio-based or earth-based materials remain rather confidential at this time. The reduction of environmental footprint is one of the major 21th century issues for the construction industry. For this purpose, a now common strategy has progressively been adopted to design material mixes by reducing the amount of cement and sometime substitute this one by less impacting earth-based materials. Another strategy would consist in designing material with only bio-based and earth-based materials. Whereas the capability of earth-based material to sustain compressive load has been proven, two major challenges are remaining: the first is related to its water sensibility, while the second one deals with material drying kinetic. Common ways to build with earth-based material refer to vernacular techniques that leads to handling, insurability, and variability of materials issues. This study proposes to focus on a bio-earth-based material, mainly dedicated to 3D printing applications, that presents a thermo-dependant behaviour able to comply with industrial building rate, and to display a high potential to increase water-resistance whatever the raw resources variability, using a mix of clay and a low amount of vegetal wax. This paper aims to build the path towards thermoplastic material solutions for 3D printing in construction, targeting thus to automate, industrialize and insure 3D printed structures.