Quantitative and Rapid Buildability Assessment Techniques for 3D-Printing Earth
Earthen construction materials are valued for their widespread availability and low embodied carbon. However, their durability and mechanical performance often require enhancement, typically achieved through chemical stabilizers. While these stabilizers can improve durability and mechanical properties, they also reduce recyclability, increase embodied carbon, and may negatively impact the material’s thermal performance. Alternatively, biopolymers can significantly enhance key properties of earthen materials, such as plasticity, viscosity, hydrophobicity, and cohesion (Losini et al., 2021). By binding and filling the voids between soil particles, biopolymers improve hygroscopic properties, allowing the material to gain strength without significantly compromising thermal performance. The combined action of the soil particles, which provide compressive strength, and the biopolymer matrix, formed through cross-links during drying, contributes to overall stability and improved shear resistance, resulting in better mechanical performance (Biggerstaff et al., 2022).
Using the appropriate amount of biopolymers and understanding their mixing strategy, based on hygroscopic properties, can enhance both the buildability and compressive strength of earthen materials. When developing a new mix for 3D printing, the biopolymer content and saturation ratio are crucial factors for achieving optimal performance. It is essential to ensure that the material mixes homogeneously and remains pumpable and extrudable, while maintaining buildability and compressive strength, as the mix density increases with the addition of biopolymers (Roussel, 2018; Rosa et al., 2020). This balance becomes more challenging in large-scale 3D printing, where each material trial is time- and energy-intensive. Rapid analysis of the material’s rheological properties is essential for optimizing buildability and strength, eliminating the need for repeated test printing of each mix. Additionally, changes in moisture content on-site can be difficult to monitor. Therefore, developing quantitative methods to assess wet-stage properties and indirectly evaluate buildability is critical for optimizing 3D-printed earth mixtures, while also ensuring effective moisture management under varying environmental conditions.
At course completion the student will:
3DPA 2024-25 Faculty : Secil Afsar Guest Faculty : Amanda Rivera INTRODUCTION Matrix of material design strategy for 3DPA 2024-2025 ANALYSIS OF PREVIOUS YEARS Mixing strategies from the previous protoypes of 3DPA EXPECTED IMPROVEMENTS Matrix for default design strategies from previous years, and areas for future improvement MATTER RESEARCH Testing different matter mixes, and additives … Read more
