The construction industry faces significant challenges, including the urgent need to minimize environmental impact and develop more efficient building methods. Additive manufacturing, commonly known as 3D-printing, has emerged as a promising solution due to its advantages, such as rapid fabrication, design flexibility, cost reduction, and enhanced safety. This technology enables the creation of structures from digital models through automated layering, presenting opportunities for mass production with innovative materials and architectural designs. This article focuses on developing eco-friendly earthen-based materials stabilized with 9 % cement and 2 % rice husk (RH) for large-scale 3D-printed construction. The raw materials were characterized using geotechnical tests for soil, water absorption tests for natural fibers, and SEM-EDS to examine their microstructure and elemental composition. Key properties such as rheology, printability (pumpability and extrudability), buildability, and compressive strength were evaluated to ensure the material's optimal performance in both fresh and hardened states. By utilizing locally sourced materials such as soil and rice husk, the mixture significantly reduces environmental impact and production costs, making it a sustainable alternative for large-scale 3D-printed construction. The material was integrated into architectural and digital fabrication techniques to construct a bioinspired housing prototype showcases the practical application of the developed material, demonstrating its scalability, adaptability, and suitability for innovative and costeffective real housing solutions. The article highlights the feasibility of using earthen-based materials for sustainable 3D-printed housing, thereby opening new possibilities for advancing greener construction practices in the future.

Incorporating sustainable stabilizers into the geo-ecosystem is an effective approach to improving the mechanical properties of the soil while addressing ecological issues. The main objective and novelty of this study are to assess the combined use of palm fiber and guar gum in soil stabilization, estimate their behavior in practices, outline their obstacles and potential for soil improvement, and consider their ecological effects. For this purpose, four different dosages of guar gum (0.5, 1, 1.5, and 2%) and three ratios of palm fiber (0.2, 0.4, and 0.6%) in lengths (5, 10, and 15 mm) were considered. Laboratory tests conducted for this purpose include compaction, compressive, shear, and tensile strength, California bearing ratio (CBR), and microstructure analysis. Initially, the optimal dosage of guar gum was determined through the unconfined compressive test. Subsequently, the impact of optimal guar gum and palm strands on the mechanical characteristics of treated soil was examined. The results revealed that compressive and shear strengths of stabilized and reinforced soil improved by 200% and 71%, respectively, compared to the control samples. Also, increasing the palm dosage improved the failure strain by up to 11.4%, cohesion enhancement by up to 96 kPa, and soil brittleness reduction by 13.5%. The tensile and CBR test results demonstrated that incorporating fiber into the soil increased its tensile strength and CBR by 32.5 kPa and 31.16, respectively. A microstructure study revealed that adding guar gum to the fiber composite improved the interlocking between clay particles and fibers by generating a hydrogel.

Although soil stabilization with cement and lime is widely used to overcome the low shear strength of soft clay, which can cause severe damage to the infrastructures founded on such soils, such binders have severe impacts on the environment in terms of increasing emissions of carbon dioxide and the consumption of energy. Therefore, it is necessary to investigate soil improvement using sustainable materials such as byproducts or natural resources as alternatives to conventional binders-cement and lime. In this study, the combination of cement kiln dust as a byproduct and zeolite was used to produce an alkali-activated matrix. The results showed that the strength increased from 124 kPa for the untreated clay to 572 kPa for clay treated with 30% activated stabilizer agent (activated cement kiln dust). Moreover, incorporating zeolite as a partial replacement of the activated cement kiln dust increased the strength drastically to 960 and 2530 kPa for zeolite ratios of 0.1 and 0.6, respectively, which then decreased sharply to 1167 and 800 kPa with further increasing zeolite/pr to 0.8 and 1.0, respectively. The soil that was improved with the activated stabilizer agents was tested under footings subjected to eccentric loading. The results of large-scale loading tests showed clear improvements in terms of increasing the bearing capacity and decreasing the tilt of the footings. Also, a reduction occurred due to the eccentricity decreasing as a result of increasing the thickness of the treated soil layer beneath the footing.