Developing 3D-printed Natural Fiber-Rich Earth Materials in Construction

Advanced manufacturing and 3D printing of clay- and earth-based materials have been recently emerging, but have been limited to little or no fiber reinforcement. Enriching 3D printable earthen composites with natural fiber reinforcement may improve durability, thermal resistivity, carbon storage potential, mechanical performance, and ductility. This study continues a line of research by the authors for developing printable fiber-rich earth composites for mixtures, focusing on defining mix-designs. The continued investigation shown in this paper focuses, specifically, on the mechanical performance and ductile behavior through bending tests that comply with ASTM C67. Importantly, the mechanical behavior here aims to comparatively investigate processing parameters – manual vs. machine mixing apparatuses – for the earth-fiber-additive composites, considering a range of agro waste co-products: wheat straw, hemp, banana, and kenaf fibers. The results show the benefits of employing the machine mixing technique for fiber homogenization, resulting in improved performance (with bending strength increased by 29 to 78%) for the 3D printed components.