This investigation examines the development of titanium slag-flue gas desulfurized gypsum-Portland cement ternary composites (the ternary composites) for the solidification and stabilization of Pb-contaminated soils. The efficacy of the ternary composites is systematically evaluated using a combination of experimental methodologies, including mechanical properties such as unconfined compressive strength, stress-strain behavior and elastic modulus, leaching toxicity, XRD, TG-DTG, FTIR, XPS, and SEM-EDS analyses. The results indicate that the mechanical properties of Portland cement solidified Pb-contaminated soils are inferior to those of Portland cement solidified Pb-free soil, both in the early and later stages. However, the mechanical properties of Pbcontaminated soils solidified by the ternary composites are superior to those of the ternary composites solidified Pb-free soils in the early stage but somewhat inferior in the later stage. The ternary composites significantly decrease the leached Pb concentrations of solidified Pb-contaminated soils, which somewhat increase with the Pb content and with the pH value decrease of the leaching agent. Moreover, with much lower carbon emissions index and strength normalized cost, the ternary composites have comparable stabilization effects on Pbcontaminated soils to Portland cement, suggesting that the ternary composites can serve as a viable alternative for the effective treatment of Pb-contaminated soils. Characterization via TG-DTG and XRD reveals that the primary hydration products of the ternary composite solidified Pb-contaminated soils include gypsum, ettringite, and calcite. Furthermore, FTIR, XPS and SEM-EDS analyses demonstrate that Pb ions are effectively adsorbed onto these hydration products and soil particles.

Waste red layers have the potential to be used as supplementary cementitious materials after calcination, but frequent and long-term dry-wet cycling leads to deterioration of their properties, limiting their large-scale application. In this study, the feasibility of using calcined red layers as cement replacement materials under dry-wet cycling conditions was analyzed. The damage evolution and performance degradation of calcined red layer-cement composites (RCC) were systematically evaluated via the digital image correlation (DIC) technique, scanning electron microscopy (SEM) analysis and damage evolution mode. The results show that the calcined red layer replacement ratio and number of dry-wet cycles affect the hydration and pozzolanic reactions of the materials and subsequently affect their mechanical properties. Based on the experimental data, a multiple regression model was developed to quantify the combined effects of the number of dry-wet cycles and the replacement ratio of the calcined red layer on the uniaxial compressive strength. As the number of dry-wet cycles increases, microcracks propagate, the porosity increases, and damage accumulation intensifies. In particular, at a high substitution ratio, the material properties deteriorate further. The global strain evolution process of a material can be accurately tracked via DIC technology. The damage degree index is defined based on strain distribution law, and a damage evolution model was constructed. At lower dry-wet cycles, the hydration reaction has a compensatory effect on damage. The pozzolanic reaction of the calcined red layer resulted in an increase in the number of dry-wet cycles. The RCC samples with high replacement ratios show significant damage accumulation with fast damage growth rates at lower stress levels. The model reveals the nonlinear effects of dry-wet cycling and the calcined red layer replacement ratio on damage accumulation in RCC. The study findings establish a scientific foundation for the resource utilization of abandoned red layers and serve as a significant reference for the durability design of materials in practical engineering applications.

This study investigates the effect of 3-aminopropyltriethoxysilane (APTES) concentration on the surface modification of rice husk (RH) for developing polybutylene adipate-co-terephthalate (PBAT) composites with varying filler loadings (30-50 wt%). Silane-treated RH was incorporated into PBAT via melt blending to enhance mechanical and thermal properties. The novelty lies in systematically correlating APTES concentration with RH loading, offering insights into their synergistic impact on composite microstructure and overall performance. Our approach provides a comprehensive understanding of how controlled silane treatment improved interfacial adhesion, mechanical strength, thermal stability, and maintained biodegradability. Characterization was performed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), tensile testing, thermogravimetric analysis (TGA), water absorption, and soil burial tests. SEM revealed a more homogeneous morphology with fewer voids. The 70PBAT/30Silane RH-2% composite achieved the best mechanical performance, outperforming 4% and 6% silane-treated composites, with tensile strength improvements of 7% and 10%, and Young's modulus increases of 12% and 4%, respectively. Tensile properties indicated that for a filler loading of 30 wt%, a 2% silane concentration is sufficient, while a maximum of 6% is required for 40 wt%, and a minimum of 4% is necessary for 50 wt% filler loading. TGA showed enhanced thermal stability with higher filler content, while soil burial tests confirmed 90% mass loss after 6 months, indicating excellent biodegradability. These results highlight the potential of silane-treated PBAT/RH composites for sustainable molded products such as trays.

This study investigates the mechanical, thermal, and wears characteristics of eco-friendly composite materials (designated as N1 to N5) with varying ratios of silicon nitride (biogenic Si3N4) and biochar along with jute and kenaf microfiber. The primary aim of this research study was to investigate the suitability of low cost biomass derived functional ceramic fillers in composite material instead of high cost industrial ceramics. Both the bio carbon and biogenic Si(3)N(4 )were synthesized from waste sorghum husk ash via pyrolysis and thermo-chemical method. Further the composites are prepared via mixed casting process and post cured at 100 degrees C for 5 h. According to results, the mechanical properties show a consistent improvement, attributed to the contributions of biogenic Si3N4. Moreover, the specific wear rate decreases progressively, with a larger biogenic Si(3)N(4 )and bio carbon filler %. The presence of biochar acts as solid lubricant and offered balanced friction coefficient. The composite N4 attained maximum mechanical properties including tensile (110 MPa), flexural (173 MPa), impact (6.1 J), hardness (82 shore-D), compressive (138 MPa) and lap shear strength (16 MPa). On contrary, the composite N5 attained least thermal conductivity of 0.235 W/mK, Sp. Wear rate of 0.00545 with COF of 0.26. Similarly, the scanning electron microscope (SEM) analysis revealed highly adhered nature of fillers with matrix, indicating their cohesive nature indicating the strong interfacial adhesion between the fillers and the matrix, attributed to the presence of biochar, which enhances mechanical interlocking and provides functional groups that promote chemical bonding with the polymer matrix, leading to improved load transfer efficiency and overall composite performance. Moreover, thermal conductivity values exhibit a marginal decline with the presence of biogenic Si(3)N(4)and biochar. Overall, the study demonstrated that biomass-derived functional fillers are capable candidates for providing the required toughness and abrasion-free surfaces, as evidenced by the increased impact strength, improved wear resistance, and enhanced durability observed in treated specimens compared to the control samples.This approach offers both economic and environmental benefits by reducing human exposure to hazardous pollutants through the utilization of biomass-derived materials, which help divert waste from landfills, lower air pollution caused by burning conventional plastics, and minimize soil contamination from non-biodegradable waste. In addition, the developed natural fiber-reinforced composites exhibited competitive mechanical performance compared to conventional industrial ceramic-reinforced composites, demonstrating comparable strength, enhanced toughness, and improved damping properties while offering the advantages of lower density, biodegradability, and cost-effectiveness. These findings highlight the potential of biomass-derived fillers as sustainable alternatives in structural applications.

All-cellulose composites (ACC) are reinforced and impregnated entirely with cellulose. In this study, ramie (Boehmeria nivea) was used as reinforcement materials because of their excellent mechanical properties and then combined with luffa (Luffa cylindrica) cellulose as the matrix to fabricate ACC with the conventional impregnation method (CIM). The NaOH/urea solution was selected to dissolve luffa cellulose. Epichlorohydrin (ECH) was added to the cellulose solution as a crosslinker for hydrogel formation. Scanning electron microscope (SEM) was conducted to evaluate the interaction between ramie fibers and luffa matrices. The mechanical properties, density, and wettability were evaluated by varying the fiber mass fraction. The results showed that ACC from ramie-luffa had a tensile strength of 35.13 MPa at a high fiber fraction, a density under 1.3 g cm-3, and an average contact angle of up to 92.1 degrees. Soil-burial testing was conducted to approach the degradability of the ACC. The results demonstrated that the degradation of ACC reached 64.41 % after 28 days of burial in the soil. These findings suggest that ACC from ramie and luffa holds significant potential as a sustainable and environmentally friendly composite.

Frozen mixed soils are widely distributed in the strata and slopes of permafrost regions. This paper aims to study the strength criterion and elastoplastic constitutive model for frozen mixed soils from micro to macro scales. Based on the knowledge of mathematical set theory and limit analysis theory, the support function of frozen soils matrix is derived. The concept of local equivalent strain is proposed to solve the problem of nonuniform deformation caused by rigid inclusions in frozen mixed soils. According to the nonlinear homogenization theory and the Mori-Tanaka method in micromechanics, the strength criterion of frozen mixed soils is established, which can consider coarse particle contents. By introducing the concepts of equivalent yield stress and equivalent plastic deformation, the elastoplastic constitutive model is proposed by the associated flow rule, which can also consider the influence of coarse particle contents. Finally, using the data in the literature, the proposed strength criterion and elastoplastic constitutive model for frozen mixed soil are verified, respectively. The effects of coarse particle contents on the mechanical properties of frozen mixed soils are discussed.

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.

This study explored mycelium-based composites (MBCs) as a sustainable alternative to conventional materials, focusing on the role of lignocellulosic substrates in optimizing their physical, mechanical, and biodegradability properties. It also addressed the valorization of agroforestry by-products, particularly European hazelnut shells (HZ) and radiata pine sawdust (SW), in an effort to reduce waste and minimize environmental impacts. The MBCs were obtained using two formulations (HZ100 and HZ75-SW25) of local agroforestry by-products bound together with natural growth of fungal mycelium from Ganoderma sp. We examined the physical and mechanical properties of these novel materials, including the density, shrinkage, water absorption, hydrophobicity, moduli of rupture and elasticity, and internal bond strength. Additionally, we assessed the biodegradability of the MBCs in soil to estimate the time required for complete degradation. The results clearly indicated differences in performance between the MBCs from HZ100 and HZ75-SW25. In general, HZ75-SW25 demonstrated superior mechanical performance compared to HZ100. Water absorption was low in both cases, suggesting a degree of hydrophobicity on the surface. The biodegradation results indicated that the fabricated MBCs could fully decompose in less than one year when buried in soil, confirming that these biocomposites are entirely biodegradable.

In this work, poly(L-lactic acid)/thermoplastic alginate (PLA/TPA) biocomposites were prepared through a melt blending method. The TPA was initially prepared using glycerol as a plasticizer. The effects of TPA content on the interactions between blend components, thermal properties, phase morphology, mechanical properties, hydrophilicity, and biodegradation properties of biocomposites were systematically investigated. Fourier transform infrared (FTIR) spectroscopy analysis corroborated the interaction between the blend components. The addition of TPA enhanced the nucleating effect for PLA, as determined by differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) revealed poor phase compatibility between the PLA and TPA phases. The thermal stability and mechanical properties of the biocomposites decreased with the addition of TPA, as demonstrated by thermogravimetric analysis (TGA) and tensile tests, respectively. The hydrophilicity and soil burial degradation rate of biocomposites increased significantly as the TPA content increased. These results indicated that PLA/TPA biocomposites degraded faster than pure PLA, making them suitable for single-use packaging, but this necessitates careful optimization of TPA content to balance mechanical properties and soil burial degradation rate for practical single-use applications.

BackgroundArchaeological limestone artifacts are subject to several deterioration factors that can cause harm while they are buried in soil, such as wet salt soil. Thus, one of the biggest challenges is restoring limestone artifacts that have been discovered from excavations. Understanding the nature of limestone after extraction and the resulting alterations, such as the stone's structural instability and the high salt content of the artifacts, are prerequisites for the restorer. In 1974 AD, King Ramesses III's gate was excavated from the ancient Heliopolis Temple in Cairo. The stones were removed from the soil and left on display outdoors at the same excavation site, where they were subject to seasonal variations in temperature and environmental changes. The main objective of the research is to select the best consolidating materials suitable for the pieces of limestone stone artifacts discovered from archaeological excavations due to their special nature, which affects them as a result of their presence in burial soil for long time. Selecting appropriate consolidating materials with appropriate characteristics was important. In order to withstand a range of environmental circumstances. The characteristics of the ancient stones at the King Ramesses III Gate site were investigated and analyzed to ascertain their true state, and their percentage of damage was calculated by contrasting them with the identical natural limestone that had not been subjected to any harmful influences. After that, experimental samples were used, and the efficacy of the treatment materials was assessed.ResultExperimental study aims to evaluate the effectiveness of some traditional and nano composites materials to improving the properties of stone artifacts extracted from archaeological excavations. Three consolidating solutions were used as follows, paraloid B72 dissolved in acetone 3%, and Calcium hydroxide nanoparticles dissolved in paraloid polymer with acetone at concentrations of 1% and 3%, in addition to nano calcium carbonate dissolved in paraloid polymer with acetone 1% and 3%. The efficiency of the consolidate materials were evaluated using a scanning electron microscope SEM, as well as measuring the water contact angle, in addition to color change testing and measuring the physical and mechanical properties.ConclusionNano materials are considered better than paraloid B72 as a consolidated material and the best outcomes results were obtained with a nano calcium carbonate dissolved in paraloid polymer with acetone 3%.