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.

The current study discusses the preparation and characterization of green composite from coarse wool fabric and natural rubber (NR) latex. Natural rubber latex was coated on the coarse wool fabric by the hand lay-up method and vulcanized to form a flexible composite sheet. Standard techniques were used to determine the physicomechanical parameters, including areal density, thickness, solvent diffusion, and abrasion resistance. Scanning electron microscopy was used to analyze the morphology of the fracture surfaces. The composite sample was further analyzed using Fourier transform infrared spectroscopy to determine changes in the chemical structure. The viscoelastic properties of the composite were investigated using a dynamic mechanical analyzer. The aging of the composite with respect to accelerated temperature, UV radiation, and soil burial was also investigated through standard methods. The developed coarse wool-rubber latex composite was found quite flexible, unlike conventional stiff fiber-reinforced composites. The scanning electron microscopy images depicted that rubber latex infiltrated the wool fabric matrix. The solvent diffusion studies showed slow penetration of water and toluene inside the composite due to a dense network of natural rubber inside the wool fabric. During the soil burial test, the composite lost 13% of its weight. A clutch bag and a shoulder bag were developed using the prepared composite. The newly developed coarse wool-NR latex composite has potential uses in technical textiles, conveyor belts, and fashion accessories.Highlights Natural rubber (NR) latex was coated on the coarse wool fabric and vulcanized. The wool-NR latex composite showed excellent physico-mechanical properties. The thermal and UV aging properties were also found to be good. The developed composite is flexible, derived purely from natural sources, and inexpensive. The wool-NR latex composite could find potential applications in fashion accessories.

Several studies focus on enhancing soil strength through the incorporation of natural or synthetic fibers. However, there is limited published data on the effectiveness of rice husk in soil reinforcement. The use of rice husk as a reinforcing material is supported by the fact that rice is one of the most produced and consumed cereals globally. In this article, we analyze the behavior of a clayey soil from southern Brazil with the addition of 0.5, 0.75, and 1% rice husk (RH), comparing it to coconut coir (CC) and curau & aacute; fibers (CU). In unconfined compressive strength tests (UCS), increases in soil strength of 20, 40, and 140% were observed for RH, CC, and CU, respectively, compared to pure soil. From consolidated undrained triaxial compression tests, both unreinforced soil and soil reinforced with 1% RH, CC, and CU were examined. The triaxial tests revealed an increase in the internal friction angle of 72 and 98%, alongside a decrease in cohesion of 57 and 94% due to the addition of CC and CU, respectively, in terms of effective stress. In contrast, RH did not significantly enhance the soil's behavior, likely due to its shorter fiber length.

Bio-mediated ground improvement techniques, including Microbial Induced Calcite Precipitation (MICP) and Enzyme Induced Calcite Precipitation (EICP) treatment methods, are extensively being employed nowadays in a variety of construction projects as newly emerging sustainable and environmentally-friendly approaches to enhance the mechanical properties and durability characteristics of earthen composites. The intrinsic brittleness of MICP- and EICP-treated soils, however, considerably limits their applications in practical geotechnical engineering. Fiber reinforcement has been widely acknowledged as an efficient solution to overcome such challenges and augment the ductility of biologically stabilized soils. Accordingly, there is growing attention to integrating natural and synthetic fibers into bio-based composites, opening up exciting possibilities for improved performance and versatility in different civil engineering applications. This review aims to examine the current state of research on utilizing fiber additives to enhance the effectiveness of MICP and EICP treatment methods in an attempt to provide an in-depth insight into the effects of fiber type, content, and length as well as the underlying mechanisms of fiber interactions within the porous structure of such treated soils. The applications of fiberreinforced bio-cemented soils, their limitations, and the major challenges encountered in practice, as well as the potential areas of interest for future research and the key factors to be considered when selecting suitable fiber for optimal soil treatment using MICP/EICP, are all critically elaborated and discussed. By synthesizing the current research findings, the study provides engineers with a valuable resource to guide the development and optimization of fiber-reinforced MICP and EICP techniques for effective soil improvement and stabilization. Based on the findings of all relevant studies in the literature, a comprehensive cost-performance-balance analysis is conducted aiming to serve as a useful guideline for researchers and practitioners interested in applying fibers in various construction projects or other related applications where either MICP or EICP technique is being utilized as the main soil stabilization approach.

This study investigated the mechanical properties of rammed earth (RE) stabilized with cement or lime and reinforced with straw. Specifically, the compressive and tensile strengths of 15 different mix designs were analyzed, including unstabilized RE, RE stabilized with lime or cement (at 4 % and 8 % by weight of soil), and RE reinforced with straw (at 0.5 % and 1.0 % by weight of soil), along with various combinations of stabilized and unstabilized RE reinforced with straw. Mechanical properties were further assessed through ultrasonic testing and scanning electron microscopy (SEM). Additionally, a data-driven fuzzy logic model was developed to estimate the mechanical properties of RE, addressing a key gap in the application of fuzzy logic to RE construction. The results showed that stabilizing RE with cement and lime increased its 28-day dry compressive strength by 365% to 640% and 109% to 237%, respectively. The addition of straw generally reduced compressive strength. The stress-strain curves indicated that the elastic modulus of RE stabilized with cement and lime increased by up to 350% and 11 %, respectively. The 28-day dry tensile strength of the samples ranged from 0.17 to 0.56 MPa. Furthermore, the addition of stabilizers improved tensile strength by approximately 88 % to 224 %, while straw enhanced the tensile strength of unstabilized RE by about 35 %. Ultrasonic and SEM analyses provided valuable insights into the mechanical properties of RE. Additionally, the fuzzy logic model proved useful, yielding satisfactory results in predicting the properties of RE, particularly when using the centroid defuzzification method. The study concluded that RE materials when properly cured and effectively stabilized with cement, lime, and straw, can achieve acceptable mechanical properties and offer sustainable benefits.

In the effort to mitigate environmental pollution there is a growing global demand for sustainable materials in place of existing synthetic one. In this research work, stacked hybrid laminate composite were produced by combining alkali treated kenaf and bamboo natural fiber mats as reinforcement with a biopolymer polylactic acid as matrix through compression moulding technique. The current work intends to study the outcome of surface modification of natural fibers which modifies their performance characteristics. Here the overall characteristics: mechanical, tribological, thermal and physical properties were investigated for the fabricated sample and the assessments were made between the alkali treated and untreated fiber composites. The alkali treated samples exhibited an enhanced tensile strength of 44.83 %, flexural strength of 108.13 %, compressive strength of 86.21 % and peak degradation temperature compared to the untreated samples. In addition, the tribological characteristics of the treated hybrid composites were studied. The inherent hydrophilic characteristics of natural fiber which leads to water absorption is resisted by the chemical treatment and it is also confirmed by the Fourier Transform Infrared (FTIR) analysis.Morphological analysis of the fractured and worn composites was also conducted to examine the microstructural changes and interface bonding within the developed composites. The biodegradability of the developed composites under soil burial test showed that the untreated composites exhibited higher weight loss percentage compared to the treated samples. The experimental results reveal that the alkali chemical treatment significantly enhances the suitability and compatibility of kenaf and bamboo natural fibers in polymer composites for sustainable construction products like roofing sheets and door panels in rural terrain regions.

The limited exploration of betel nut shell fibers (BNSF) in hybrid natural fiber composites motivates this research to fill the existing gap in fabricating a novel hybrid composite material of BNSF with notably strong mechanical properties. This study explores the impact of BNSF on the properties of an epoxy/banana composite. It investigates the mechanical strength, moisture absorption, and biodegradability of the composite. Results show that a 5 wt. % inclusion of BNSF significantly enhances the tensile strength of epoxy/banana/BNSF hybrid composite compared to that of epoxy/banana composite. All the composites show remarkable flexural strength and the highest of all can be seen in the hybrid composite with 10 wt. % of BNSF. Moisture absorption increases with fiber content, reaching 10.71% for the composite with 50 wt. % banana fiber. Biodegradability test in soil results in 71.23% degradation of the hybrid composite with 15 wt. % BNSF. The experimental and finite element analysis results are in good agreement with each other, therefore validating the accuracy of the experimental findings. The remarkable strength of the fabricated hybrid composite confirms the scope of the composite in automobile interiors, furnitures, packaging, decorative items etc.

Millions of tonnes of bagasse are annually generated as waste from the sugar industry, the disposal of which poses a critical global challenge. To address this, the study explores the potential utilization of sugarcane bagasse fibers as a reinforcing material to sand, aiming to enhance its mechanical properties through laboratory investigations. Initially, the primary physical characteristics of both sand and bagasse fibers are examined using laboratory tests and scanning electron microscopy. Further, consolidated drained triaxial compression tests were carried out on sand specimens, with fiber contents varying from 0 to 2%. The investigations encompass the influence of fiber content, fiber length, and effective confining pressures on the strength parameters, dilation, and stiffness of reinforced sand. Upon shearing, the bagasse reinforced sands exhibited a strain-softening behavior at low fiber contents and a strain hardening behavior at higher fiber contents. Results indicate the beneficial utilization of bagasse fiber in enhancing the strength parameters, and reducing the residual strength loss of sand, sensitive to the effective confining stress. With increase in percentage of bagasse fiber, the dilation of sand was found to be decreasing. The inclusion of bagasse fibers also leads to a reduction in the initial and secant stiffness of the sand. Furthermore, as the length of fiber shortens at same percentage of fiber, the peak and critical angle of friction reduces. Based on the test results, a normalized model of the reinforced sand has been developed to capture the peak and residual states of the sand in correlation with different critical parameters.

The accumulation of plastics in the environment is a well-recognized issue. To address this, biodegradable materials such polylactic acid (PLA) have been developed. In natural environments such as soil or water, PLA degradation progresses slowly but steadily. To accelerate the degradation of the material, this study investigates the degradation of a biocomposite material using PLA as a matrix and Pennisetum setaceum fiber as reinforcement. Disintegration and marine biodegradability tests, both at the seawater/sediment interface and in marine sediment, were conducted. Different measurement tests were employed to quantify the degradation of PLA and composite samples, focusing on the mass loss and the variation of the mechanical and thermal properties. The results consistently demonstrated greater mass loss and mechanical property deterioration during the disintegration test compared to the marine biodegradability tests. Notably, the composite material exhibits more significant degradation than the pure polymer without fiber. For composite, the addition of fiber increased the degree of biodegradability compared to the plastic matrix.

Expansive soils, prone to significant volume changes with moisture fluctuations, challenge engineering infrastructure due to their swelling and shrinking. Traditional stabilization methods, including mechanical and chemical treatments, often have high material and environmental costs. This study explores fibrous by-products of flax processing, a sustainable alternative, for reinforcing expansive clay soil. Derived from the Linum usitatissimum plant, flax fibers offer favorable mechanical properties and environmental benefits. The research evaluates the impact of flax tow (FT) reinforcement on enhancing soil strength and reducing cracking. The results reveal that incorporating up to 0.6% randomly distributed FTs, consisting of technical flax fibers and shives, significantly improves soil properties. The unconfined compressive strength (UCS) increased by 29%, with 0.6% FT content, reaching 525 kPa, compared to unreinforced soil and further flax tow additions, which led to a decrease in UCS. This reduction is attributed to diminished soil-fiber interactions and increased fiber clustering. Additionally, flax tows effectively reduce soil cracking. The crack length density (CLD) decreased by 6% with 0.4% FTs, and higher concentrations led to increased cracking. The crack index factor (CIF) decreased by 71% with 0.4% flax tows but increased with higher FT concentrations. Flax tows enhance soil strength and reduce cracking while maintaining economic and environmental efficiency, offering a viable solution for stabilizing expansive clays in geotechnical applications.