The structures and the physical and mechanical properties of Ferrocalamus strictus culms were differently affected by the environment in different habitats. Correlation analysis, random forest and cluster analysis were used to investigate the effects of environmental factors in five habitats on the structure and physical and mechanical properties of bamboo poles or stalks of F. strictus. The air-dry density of F. strictus stalks ranged from 0.66 to 0.91 g/cm3. Data showed that the average annual temperature, soil water content and available potassium content were important factors affecting air-dry density the bamboo stalks. The compressive strength of F. strictus stalks varied from 60.62 to 126.16 MPa and was positively correlated with mean annual sunshine hour. The modulus of rupture (MOR) ranged from 57.95 to 252.09 MPa and the soil available phosphorus content limited the MOR of F. strictus. The modulus of elasticity (MOE) ranged from 6.04 to 12.89 GPa. The outer hardness ranged from 66.75 to 94.83 HD (Shore D hardness) and the inner hardness ranged from 28.42 to 58.42 HD. Soil silicon content affected the structures and mechanical tissue strength of F. strictus culms. The principal component analysis indicated that the Yuanyang was the optimal habitat of F. strictus with highest composite scores of 14.07, the F. strictus of Yuanyang had the highest bending strength in the world, suggested that selecting a habitat site as breeding materials be reasonable. The regulation of hydrothermal conditions, i.e. soil pH, silicon (Si), phosphorus (P) and potassium (K) elements, was essential for the growth rate and physical and mechanical properties of F. strictus stalks. Further research will work on regulating the growth conditions of F. strictus at Yuanyang according to the information found from this paper and evaluating the impact of regulation.

The study investigates the mechanical requirements for harvesting coriander (Coriandrum sativum L.) by analyzing static and dynamic cutting forces for three distinct varieties: SIMCO, GCr1, and GCr2. Through controlled laboratory experiments, the static cutting force was measured using a texture analyzer across variations in blade speed (2, 4, 6, 8, and 10 mm/s), stem number (1-5), cutting height (50, 75, 100, 125, and 150 mm), and moisture content (23 %, 30 %, and 37 %). The static cutting force for SIMCO was found to be the highest (151.6 N), followed by GCr1 (145.68 N) and GCr2 (140.48 N), primarily due to stem structure and diameter differences. The dynamic cutting force was also measured in the indoor soil bin using a reciprocating cutter bar by simulating the field conditions at varied forward speeds (0.3, 0.6, 0.9, and 1.2 m/s), cutter bar speeds (2, 8, 14, and 20 strokes/s), and cutting heights (50, 75, 100, 125, and 150 mm). For dynamic cutting, the SIMCO variety required an average maximum force of 33.14 N, which was 6.85 % and 7.06 % higher than GCr1 and GCr2 respectively. The dynamic cutting forces were influenced most significantly by cutter bar speed and forward speed, with optimal cutting achieved at 20 strokes/s cutter bar speed and 0.3 m/s forward speed. Response Surface Methodology (RSM) models with R2 values above 0.99 effectively predicted both static and dynamic cutting forces, indicating strong model adequacy and providing detailed insights into the interactions between parameters. The analysis revealed that the number of stems and blade speed were the primary influencers on static cutting force, while the dynamic force was most affected by cutter bar speed and forward speed. This study highlights the importance of customized parameter settings to enhance harvester efficiency, reduce energy consumption, and minimize seed damage during harvest.

Vegetation concrete is one of the most widely used substrates in ecological slope protection, but its practical application often limits the growth and nutrient uptake of plant roots due to consolidation problems, which affects the effectiveness of slope protection. This paper proposed the use of a plant protein foaming agent as a porous modifier to create a porous, lightweight treatment for vegetation concrete. Physical performance tests, direct shear tests, plant growth tests, and scanning electron microscopy experiments were conducted to compare and analyze the physical, mechanical, microscopic characteristics, and phyto-capabilities of differently treated vegetation concrete. The results showed that the higher the foam content, the more significant the porous and lightweight properties of the vegetation concrete. When the foam volume was 50%, the porosity increased by 106.05% compared to the untreated sample, while the volume weight decreased by 20.53%. The shear strength, cohesion, and internal friction angle of vegetation concrete all showed a decreasing trend with increasing foaming agent content. Festuca arundinacea grew best under the 30% foaming agent treatment, with germinative energy, germinative percentage, plant height, root length, and underground biomass increasing by 6.31%, 13.22%, 8.57%, 18.71%, and 34.62%, respectively, compared to the untreated sample. The scanning electron microscope observation showed that the pore structure of vegetation concrete was optimized after foam incorporation. Adding plant protein foaming agents to modify the pore structure of vegetation concrete is appropriate, with an optimal foam volume ratio of 20-30%. This study provides new insights and references for slope ecological restoration engineering.

Surface-applied mulches help retain soil moisture and optimize soil temperature while preventing weed growth and benefiting many horticultural crops. The most common mulch material is low-density polyethylene (LDPE), is typically landfilled, buried, or burned at the end of growing season causing negative environmental impacts. The goal of this research was to develop soil-biodegradable, liquid-applied (i.e., hydromulch) alternatives to LDPE mulch and optimize formulations that are acceptable for organic horticulture. Hydromulch (HM) treatments contained mixtures of paper pulp, wood fiber, or hemp hurds (Cannabis sativa L.) combined with various tackifiers and water. The tackifiers were guar gum (Cyamopsis tetragonoloba (L.) Taub.), psyllium husk (Plantago ovata L.), and camelina meal (Camelina sativa (L.) Crantz), included at various proportions. Hydromulch samples were tested for physical properties (density, water holding capacity, C:N ratio, soil adhesion) and mechanical properties (tensile strength, puncture resistance). Hydromulches containing no tackifiers were included as controls to determine if the addition of tackifiers resulted in enhanced mechanical properties. The results showed addition of 6% guar gum tackifier improved the tensile strength and puncture resistance by 182% and 91 % respectively compared to control sample, and HM formulations containing paper were 200 % or more stronger than those containing wood or hemp hurds. Increased tackifier proportion was found to improve most mechanical properties, with guar gum performing best. Blending of tackifiers resulted in an interaction that decreased strength. Hydromulches containing wood fiber and hemp hurds did not show promising results. Paper in HM formulations helped to reduce mulch porosity and improved adhesion to soil. Results from the study provide a foundation on optimal formulations for expanded trials at field-scale.

In the actively evolving research of Mars in recent decades, a special place is occupied by landers and rovers. The diversity of landscapes and soils on Mars, characteristic of terrestrial planets with an atmosphere, makes the development of soil simulators relevant for each new type of terrain in the area of a potential landing site. In the article, based on a comprehensive analysis of the physical and mechanical properties of soils at previous landing sites and a geomorphological analysis of the Oxia Planum plain, the main requirements for the properties of Martian soil analog at the landing site of the ExoMars Rosalind Franklin Mission (RFM) were determined. Readily available technogenic and natural materials have been selected and experimentally justified as components for creating a Martian soil analogue. A methodology for creating the soil analog is presented, and its physical and mechanical properties are measured. The developed Martian soil analog VI-M1 is actively used for large-scale natural experiments, including drop tests of spacecraft in the ExoMars series.

Clay-based mortars are susceptible to water intake and exhibit low mechanical strength, presenting challenges in their application within the construction sector. This research addresses these vulnerabilities by investigating the combination of alkali activators with waterproofing agents, specifically a nano-clay and an acrylic emulsion, to enhance the properties of clay mortars. Alkali-activated materials are known for their superior mechanical properties and sustainable potential, especially when derived from low-cost by-products. Recent studies have focused on alkali activation using clays and soils as precursors to improve their physical and mechanical properties while increasing durability. However, the high absorbency of these mortars remains a concern, as it can lead to matrix degradation. Therefore, to address these problems, this research studied the combination of a highly alkaline activator (potassium metasilicate) with hydrophobic agents, such as a nano-clay and an acrylic emulsion, using two different clayey soils. The results indicated that potassium metasilicate (PO) enhanced the mechanical properties and stability for both aluminosilicate systems, while nano-clay (PONC) significantly reduced the capillary absorption through time, especially in A2 systems. The addition of acrylic emulsion (POD) proved highly effective in both systems, significantly improving durability. By integrating these agents, the mortar systems were protected against water intake, while durable construction materials were formed.

In view of the specialized climatic conditions in high-cold and high-altitude regions, the direct, repeated freezethaw and freezing processes resulting from diurnal and seasonal temperature changes pose a significant threat to the integrity of the roadbed stones in these areas. Weathering and fragmentation constitute a form of rock damage. Rock damage negatively impacts the air convection within the rock subgrade, rendering it incapable of safeguarding frozen soil. The objective of this study is to investigate the mechanical properties and the constitutive model for freeze-thaw damage of three recycled weathered rock materials subjected to varying freeze-thaw cycles. Additionally, it aims to examine the damage and degradation mechanism of recycled weathered rock materials under the combined influence of freeze-thaw and load. The model is then employed to validate the experimental data. Research indicates that with an increase in the number of freeze-thaw cycles, the quality of the three types of recycled weathered rock samples exhibits a gradual decrease, accompanied by a corresponding reduction in P-wave speed. The elastic modulus and compressive strength of the three recycled weathered rock materials show an increase with rising confining pressure and a decrease with a growing number of freeze-thaw cycles. The types of damage include splitting and shear damage. The presented damage model can elucidate the pattern of damage evolution in the specimen under varying confining pressures and freeze-thaw cycles. The expansion of internal micro-cracks is influenced differently by freeze-thaw cycles and loads; moreover, the coupling effect of damage exhibits pronounced nonlinear characteristics. Substantiated by experimental results, the damage constitutive model demonstrates both reasonability and feasibility.

The objective of this study was to improve the physical and mechanical properties of adobes reinforced by cement-metakaolin mixtures. For this purpose, a raw clayey material from Burkina Faso consisting of kaolinite (62 wt%), quartz (30 wt%), and goethite (6 wt%) and belonging to the category of sandy-silty soils with medium plasticity has been used for adobe manufacturing. Metakaolin was produced by thermal activation of a local raw clayey material at 680 degrees C for 2 h. Adobes were first formulated with cement up to 12 wt%. It appears from this formulation that 10 and 12 wt% cement offer good mechanical strength elaborated adobes. Taking into account the high cost of cement in Burkina Faso, 10 wt% of cement was retained to be replaced by 2, 4, 6, 8, and 10 wt% metakaolin. The microstructural (by SEM-EDS), physical (apparent density, porosity, linear shrinkage, water absorption test by capillarity, spray test), and mechanical (compressive and flexural strengths) characteristics of formulated adobes were evaluated. The obtained results showed that this substitution improved adobe microstructure with pores reduction leading to composite densification. The presence of metakaolin slows down the phenomenon of capillary rise of water in adobes. Also, the metakaolin presence within the cementitious matrix improves the mechanical behavior and reduces rain erosion effect. The improvement of different properties was mainly due to formation of calcium silicate hydrates (CSH) resulting by cement hydration and metakaolin's pozzolanic reaction. Adobes reinforced with 6 wt% cement and 4 wt% metakaolin have suitable technological characteristics to be used as building materials for developing countries.

This paper studies the influence of shea butter residues on the physical and mechanical performance of earth renders. Mineralogical and microstructural characteristics of shea butter residues as well as the physical and mechanical parameters of earth renders were evaluated. The results showed that shea butter residues are mainly composed of fatty substances. To enhance physical and mechanical performance of earth renders, contents varying from 0 to 6 wt% of shea butter residues were added to a local clayey soil, predominately composed of kaolinite (60 wt%), quartz (31 wt%) and feeble amount of goethite (2 wt%). This study showed that the incorporation of shea butter residues to earth renders improved meaningfully their physico-mechanical properties such as water and erosion resistance. This is particularly attributable to the hydrophobic properties of fatty substances contained in shea butters. Furthermore, shea butter residues incorporation increases earth renders porosity which contributes to reduce mechanical resistance and thermal conductivity and making the renders more insulating. Taking into account construction standards based on the protection of earth buildings and also their advantageous hydric properties and insulating power, earth renders amended with shea butter could be an adequate and affordable habitat building material throughout tropical regions of the world. Shea butter residues addition to earth renders decreases their linear shrinkage.Earth renders amended by shea butter residues have good water resistance.Shea butter residues addition to earth renders decreases their thermal conductivity.Lipidic molecules in shea butter residues explain these observed improvements.

In order to study the improvement effect of the CG-2 curing agent and cement on loess, a series of physical and mechanical property tests and microstructure tests were carried out on loess improved with different dosages of curing agent and cement to study the physical and mechanical properties, durability and microscopic pore characteristics of the CG-2 curing agent and cement-improved loess. The results show that the unconfined compressive strength of improved loess increases gradually with the increase in curing agent and cement dosage, and the higher the compaction degree and the longer the curing age, the higher the unconfined compressive strength. In the case of the same cement content, the higher the dosage of curing agent, the more the unconfined compressive strength of improved loess increases. Under the condition of reaching the same unconfined compressive strength, the addition of curing agent can significantly reduce the amount of cement. The more the content of cement and curing agent, the less the unconfined compressive strength decreases after a certain number of freeze-thaw cycles, and the higher the dry-wet cycles index after a certain number of dry-wet cycles, indicating that the addition of curing agent can significantly improve the ability of the sample to resist freeze-thaw cycles and dry-wet cycles. According to the microscopic test results, it is found that the addition of curing agent can reduce the porosity of soil particles, change the contact and arrangement mode between soil particles, and enhance the agglomeration and cementation characteristics between soil particles, and obviously improve the physical and mechanical properties of soil. The research results can provide new ideas and methods for the improvement technology of loess.