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The bank protection measures of waterways shall become more environmentally friendly in the future including the use of plants instead of stones. The low levels of protection provided by plants in the early phase after planting requires a process-based understanding of soil-wave-interaction. One process that is considered essential is liquefaction where the soil undergoes a phase-change from solid-like to fluid-like behaviour which could reduce the safety of the system. The aim of this publication is to analyse the results of column experiments on wave-induced soil liquefaction and to develop a numerical model which is able to describe the entire process from the pre-liquefaction phase to the following reconsolidation in order to support the analysis of liquefaction experiments. Numerical simulations of the column experiments were done using a fully coupled hydro-mechanical model implemented in the open-source software FEniCS. A permeability model derived from granular rheology allows the simulation of dilute as well as dense suspensions and sedimented soil skeletons. The results of the simulations show a good agreement with the experimental data. Theoretical limits in the liquefied state are captured without the common modelling segmentation into pre-and post-liquefaction phase. Due to the modular structure of the implementation, the constitutive setting can be adjusted to incorporate more complex formulations in order to study the influence of wall friction and non-linearity in soil behaviour.

期刊论文 2025-09-01 DOI: 10.1016/j.compgeo.2025.107321 ISSN: 0266-352X

This study investigates the potential of graphene-based additives to improve the mechanical properties of compacted soil mixtures in rammed-earth construction, contributing to the development of environmentally friendly building materials. Two distinct soils were selected, combined with sand at optimized ratios, and treated with varying concentrations of a graphene liquid solution and a graphene-based paste (0.001, 0.005, 0.01, 0.05, and 0.1 wt.% relative to the soil-sand proportion). The effects of these additives were analyzed using the modified Proctor compaction and unconfined compressive strength (UCS) tests, focusing on parameters such as optimum water content (OWC), maximum dry density (MDD), maximum strength (qu), and stiffness modulus (E). The results demonstrated that graphene's influence on compaction behavior and mechanical performance depends strongly on the soil composition, with minimal variation between additive types. In finer soil mixtures, graphene disrupted particle packing, increased water demand, and reduced strength. In silt-sandy mixtures, graphene's hydrophobicity and limited interaction with fines decreased water absorption and preserved density but likewise led to diminished strength. Conclusions from the experiments suggest a possible interaction between graphene, soil's finer fraction, and potentially the swelling and non-swelling clay minerals, providing insights into the complex interplay between soil properties.

期刊论文 2025-02-19 DOI: 10.3390/c11010016

Sandy soils are a type of geomaterial that may require improvements due to lack of cohesion. In this study, first, the lack of cohesion of sand was resolved using clay, and the soil was stabilized with cement and lime (4% and 3% of the dry weight of materials, respectively) and finally reinforced with recycled tire fibers of 20 to 30 mm in length for improved strength and ductility. Next, 747 samples with different fiber contents at different curing temperatures and ages were prepared and a unconfined compressive strength (UCS) test was carried out. Next, a novel approach employing multivariate nonlinear regression techniques and obtained empirical data was applied to formulate a mathematical model for predicting the UCS and the modulus of elasticity (E-s) of the reinforced and stabilized soil. This model can serve as a valuable tool for building engineers in designing building foundations. The comparison of the obtained UCS and E-s results and those predicted using the proposed model showed a correlation of >95% (R-2 >= 0.95). The fibers effectively increased the failure strain, thus resulting in the greater ductility of the samples. As an example, in 14-day samples cured at 60 degrees C with 0%, 0.4%, 1%, 1.7%, and 2.5% fibers, the failure strain showed an incremental trend of 1.47%, 1.87%, 2.08%, 2.20%, and 2.92%, respectively. Scanning electron microscopy (SEM) was used to study the microstructure of the samples and to explain the strength experimental outcomes. SEM images showed a desirable interaction between the fiber surfaces with the soil mass and the reduction in porosity and the occurrence of pozzolanic reactions through stabilization. The results also showed that the reinforcement effectively improved the ductility, as desired for building foundations; however, it resulted in reduced strength, although a greater strength compared to the untreated soil was achieved. Although soil stabilization has been widely studied, limited research focuses on stabilizing soil with clay, lime, cement, and recycled tire fibers. This study offers design engineers an estimation scheme of the strength properties of stabilized and reinforced foundations.

期刊论文 2025-02-01 DOI: 10.3390/buildings15030382

Natural rubber (NR) is a material with a wide range of industrial and commercial applications, including agriculture, defense, transportation, and domestic use. However, the mechanical properties of natural rubber treated by traditional acid coagulation are limited, which restricts its application in high-end products. Furthermore, the wastewater generated also causes soil acidification. Consequently, there is a necessity to investigate new coagulation methods to enhance the comprehensive performance of natural rubber and reduce environmental pollution. In this work, a novel method for the preparation of environmentally friendly high-performance natural rubber by alkaline protease/calcium chloride coagulation of natural rubber (AC-NR) is reported. The research demonstrates that the products of protein cleavage by alkaline protease together with calcium ions can greatly enhance the cross-linking between rubber particles, form the network structure of natural rubber well. Furthermore, increasing the pH at the isoelectric point of the discharged wastewater reduces the impact on soil acidification. In comparison with those from conventional acid coagulation of natural rubber (A-NR), the tensile strength of AC-NR was increased by 7.9 MPa, the tear strength was increased by 5.3 kN/m, the final temperature rise was lowered by 6.5 degrees C, and abrasion performance was improved. This study demonstrates that by utilizing the collaborative impact of alkaline protease and calcium chloride on the rubber molecular chain during the coagulation process of natural rubber, environmentally friendly high-performance natural rubber with excellent mechanical properties and reduced environmental pollution can be prepared without the necessity for chemical modification or cumbersome processes, which is conducive to the green development and high-quality pursuit of NR materials.

期刊论文 2025-02-01 DOI: 10.3390/polym17040490

Root-knot nematodes (Meloidogyne spp.) are significant pests that cause considerable damage to crops, prompting a need for sustainable control methods. This study evaluated the nematicidal potential of fungal culture filtrates and botanicals as eco-friendly alternatives. In vitro tests demonstrated that Lemongrass oil (LG) (0.2%) achieved the highest mortality of nematode juveniles (J2s) at 99.44% within 48 h, while Pochonia chlamydosporia (Pc) (2%) and Purpuricillium lilacinum (Pl) (2%) reduced egg hatching rates to 9.57% and 11.43%, respectively. Neem oil (NM) (0.2%) was the most effective in preventing J2 root penetration (4.42%). In vivo, a combination treatment (T7) of NM (0.2%), Trichoderma harzianum (Tz) (2%), Pl (2%), and LG (0.2%) applied at 10 day intervals significantly reduced the nematode reproduction factor to 0.035, comparable to the chemical control Bayer Velum Prime (R) (Fluopyram 34.48% W/W SC) (0.031). T5 (NM and Tz) resulted in the highest shoot biomass (236.73 +/- 1.38 g), while Bayer Velum Prime (R) (Fluopyram 34.48% W/W SC) increased root biomass (31.75 +/- 1.24 g). Additionally, T7 produced the longest shoots (63.37 +/- 0.74 cm) and roots (36.80 +/- 0.3 cm), with fewer root galls (55.67 +/- 1.53) and egg masses (4 +/- 0.01). T7 also minimized the final soil nematode population to 106.33 +/- 1.01 per 100 g, closely followed by T8 (94.67 +/- 0.89). These results indicate that combining NM, Tz, Pl and LG provide effective nematode control without phytotoxic effects, enhancing plant growth and offering a promising sustainable alternative to chemical nematicides.

期刊论文 2025-01-02 DOI: 10.1038/s41598-024-84292-5 ISSN: 2045-2322

Civil and geotechnical researchers are searching for economical alternatives to replace traditional soil stabilizers such as cement, which have negative impacts on the environment. Chitosan biopolymer has shown its capacity to efficiently minimize soil erosion, reduce hydraulic conductivity, and adsorb heavy metals in soil that is contaminated. This research used unconfined compression strength (UCS) to investigate the impact of chitosan content, long-term strength assessment, acid concentration, and temperature on the improvement of soil strength. Static triaxial testing was employed to evaluate the shear strength of the treated soil. Overall, the goal was to identify the optimum values for the mentioned variables so that the highest potential for chitosan-treated soil can be obtained and applied in future research as well as large-scale applications in geotechnical engineering. The UCS results show that chitosan increased soil strength over time and at high temperatures. Depending on the soil type, a curing temperature between 45 to 65 degrees C can be considered optimal. Chitosan biopolymer is not soluble in water, and an acid solution is needed to dissolve the biopolymer. Different ranges of acid solution were investigated to find the appropriate amount. The strength of the treated soil increased when the acid concentration reached its optimal level, which is 0.5-1%. A detailed chemical model was developed to express how acid concentration and temperature affect the properties of the biopolymer-treated soil. The SEM examination findings demonstrate that chitosan efficiently covered the soil particles and filled the void spaces. The soil was strengthened by the formation of hydrogen bonds and electrostatic interactions with the soil particles.

期刊论文 2025-01-01 DOI: 10.3390/polym17020151

Concrete curing is a critical factor influencing its mechanical properties and durability. Traditional curing methods, such as water curing and plastic film curing, have significant limitations, including high water consumption and environmental pollution. This study introduces Microbial Induced Carbonate Precipitation (MICP) as an innovative, environmentally friendly curing method for ready-mixed concrete, addressing the urgent need for sustainable construction practices. The feasibility of MICP surface curing is investigated through comprehensive mechanical and durability tests, coupled with microscopic analyses to understand the underlying mechanisms. The results demonstrate that MICP curing substantially enhances concrete performance. Compared to traditional water curing, the samples cured using MICP have increased compressive strength and splitting tensile strength by up to 31.69% and 24.66%, respectively. Additionally, MICP surface curing significantly reduced capillary water absorption, electric flux, and chloride ion migration coefficient by 12.83%, 15.50%, and 17.36%, respectively. It is found that the optimal concentration of Ca2+ in the MICP solution initially improves concrete performance, which then diminishes at higher concentrations due to bacterial activity inhibition. Spraying the MICP solution at appropriate intervals and increasing the number of treatments further improved concrete properties by ensuring a more extensive and dense deposition of CaCO3. Microscopic analyses, including XRD, TG, and SEM-EDS, revealed that MICP surface curing leads to the formation of vaterite and calcite, which densely cover and fill microscopic cracks and pores, ensuring adequate hydration and simultaneously enhancing the concrete's mechanical and durability properties. This study concludes that MICP surface curing provides superior performance than traditional methods and offers a more sustainable and environmentally friendly curing method.

期刊论文 2024-11-01 DOI: 10.1016/j.jclepro.2024.143962 ISSN: 0959-6526

In light of the growing plastic waste problem worldwide, including in agriculture, this study focuses on the usefulness of both conventional, non-degradable plastics and environmentally friendly bioplastics in the agricultural sector. Although conventional plastic products are still essential in modern, even ecological agriculture, the increasing contamination by these materials, especially in a fragmented form, highlights the urgent need to search for alternative, easily biodegradable materials that could replace the non-degradable ones. According to the literature, polymers are widely used in agriculture for the preparation of agrochemicals (mostly fertilizers) with prolonged release. They also play a role as functional polymers against pests, serve as very useful super absorbents of water to improve crop health under drought conditions, and are commonly used as mulching films, membranes, mats, non-woven fabrics, protective nets, seed coatings, agrochemical packaging, or greenhouse coverings. This widespread application leads to the uncontrolled contamination of soil with disintegrated polymeric materials. Therefore, this study highlights the possible applications of bio-based materials as alternatives to conventional polyolefins or other environmentally persistent polymers. Bio-based polymers align with the strategy of innovative agricultural advancements, leading to more productive farming by reducing plastic contamination and adverse ecotoxicological impacts on aquatic and terrestrial organisms. On the other hand, advanced polymer membranes act as catching agents for agrochemicals, protecting against environmental intoxication. The global versatility of polymer applications in agriculture will not permit the elimination of already existing technologies involving polymers in the near future. However, in line with ecological trends in modern agriculture, more green polymers should be employed in this sector. Moreover, we highlight that more comprehensive legislative work on these aspects should be undertaken at the European Union level to guarantee environmental and climate protection. From the EU legislation point of view, the implementation of a unified, legally binding system on applications of bio-based, biodegradable, and compostable plastics should be a priority to be addressed. In this respect, the EU already demonstrates an initial action plan. Unfortunately, these are still projected directions for future EU policy, which require in-depth analysis.

期刊论文 2024-10-01 DOI: 10.3390/su16198439

The utilization of lignosulfonate (LS) as a naturally derived biopolymer sourced from lignin in soil stabilization has gained significant attention in recent years. Its intermolecular interaction, hydrophobic and hydrophilic effects, adhesive and binding properties, erosion control abilities, compatibility with various soil types, and environmental sustainability make it a promising alternative to traditional soil stabilizers as well as highlighting its importance. By integrating LS into soil stabilization practices, soil properties can be enhanced, and an ecofriendlier approach can be adopted in the construction sector. This comprehensive review paper extensively examines the applications and structure of LS, as well as their efficacy and mechanisms on a micro-level scale. Afterward, it discusses the geotechnical characteristics of LS-treated soils, including consistency characteristics, dispersivity properties and erosion behavior, electrical conductivity, compaction parameters, permeability and hydraulic conductivity, compressibility characteristics, swelling potential, strength and stiffness properties, durability, and cyclic loading response. In general, LS incorporation into the soils could enhance the geotechnical properties. For instance, the Unconfined Compressive Strength (UCS) of fine-grained soils was observed to improve up to 105 %, while in the case of granular soils, the improvement can be as high as 450 %. This review also examines the economic and environmental efficiency, as well as challenges and ways forward related to LS stabilization. This can lead to economic and environmental benefits given the abundance of LS as a plant polymer for cleaner production and owing to its carbon neutrality and renewability.

期刊论文 2024-09-15 DOI: 10.1016/j.scitotenv.2024.173500 ISSN: 0048-9697

State of the problem. In the article, it is justified that the provision of a green economy based on environmentalization, modernization, innovation and new technologies in the production and processing of agricultural products leads to a radical improvement of production, protection of natural capital and ecosystem services, and reduction of pollution and greenhouse gas emissions. It was noted that the regulation of agricultural production systems in the country requires the expansion of agricultural practices that increase productivity and production, contribute to the protection of ecosystems, adaptation to climate change, extreme weather events, droughts, and floods. Research object. It is the production, processing, consumption and export of agricultural products of Azerbaijan. The purpose of the study is to promote the production of ecologically clean and export-important consumer products in Azerbaijan and the stimulation of its export. Introducing the country to the world with branded products, attracting foreign investments to this field, increasing the population's interest in the agricultural field, and attracting innovative technology to the field are also considered important. It is the determination of the damage caused by the impact on the agricultural sector and nature due to the degradation of the growing environmental components. Minimizing losses at this stage and optimizing the development of the agro-industrial complex is one of the main factors. Methodology. Generalization, historical, statistical, systematic analysis and comparison methods were used in the preparation of the article. Scientific novelty of the research. Implementation of the production and processing of ecologically clean agro-industrial products that do not harm human health and the environment, regular monitoring of the ecological condition of the soil, and the provision of increasing the production and assortment of ecologically clean export-oriented food and light industrial products. Research results. In the article, it is explained that the development of the green economy in Azerbaijan is an integral part of the state policy, and it occupies an important place in the state administration, on the example of export-oriented food and light industrial products. It is noted that the sustainability of the development of the green economy acts as a criterion for the production of competitive products of the state, which contributes positively to the provision of people's vital needs.

期刊论文 2024-01-01 DOI: 10.26565/2410-7360-2024-60-32 ISSN: 2410-7360
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