River Sand Research Articles

Mechanical and sustainability performance of concrete with discarded coconut coir as an alternative to conventional sand

Due to increased construction activities, the demand for construction material increases, which causes depletion of natural resources such as river sand in Asian countries. Therefore, the present study aims to replace conventional sand with discarded coconut coir (CC) and examines the engineering and sustainable performance of concrete. The proportion of CC in the concrete mix was 25%, 50%, 75% and 100%. Replacement of river sand with CC tends to decline the strength from 32 to 83% after 28-d of curing. In addition to the mechanical properties, the concrete blended with CC was subjected to temperature exposure as per ISO 834 guidelines. Four different heating durations were adopted, namely, 821 ℃ (for 30 min), 925 ℃ (for 60 min), 986 ℃ (for 90 min), and 1029 ℃ (for 120 min). The mass loss in concrete with the incorporation of CC after subjecting to elevated temperature was found to be 5–14%. Strength loss was observed in the range of 61–85% after subjecting to 30–120 min of heating. In the case of environmental impacts, the carbon efficiency of the concrete without CC was 0.010 t-CO2/MPa whereas the concrete with 100% CC was found to be 0.063 t-CO2/MPa, showing that the concrete blended with CC possesses superior performance. Moreover, in the case of an economic index, the concrete blended with 100% CC possesses 81% higher efficiency than the concrete with conventional aggregates. Similarly, the sustainability index of the concrete with CC shows 83% higher efficiency.

Performance Study and Reliability Analysis of Desert Sand Concrete Under FTC

Using desert sand (DS) to pour concrete is a feasible idea to solve the shortage of river sand. However, the frost resistance of desert sand concrete (DSC) is a key problem that must be solved for applying DSC in practical engineering. Therefore, this study on the performance and reliability analysis of DSC under a freeze–thaw cycle (FTC) was carried out. The DSC specimens were subjected to the FTC test with desert sand replacement ratios (DSRRs) of 0%, 20%, 40%, 60%, 80%, and 100%. Then, the appearance, mass, relative dynamic elastic modulus (RDEM), and compressive strength of DSC were analyzed and discussed. Moreover, the damage mechanism of DSC was discussed via microstructural analysis. The results indicated that as the FTCs increased, the mass loss rate of concrete increased, while the RDEM and compressive strength decreased. Among the samples, DSC-40 showed the best resistance to the FTC. After 250 cycles, the changes in mass, RDEM, and compressive strength of DSC-40 were 2.73%, 15.19%, and 27.2% lower than those of DSC0. Finally, the DSC reliability model was established by using the Weibull probability distribution method. Among all groups, DSC-40 showed the best reliability, and the failure life was 287 FTCs, which was approximately 1.55-times longer than DSC0. This model could provide a theoretical basis for the durability evaluation and life prediction of DSC structures in cold regions.

Study on the Influence and Mechanism of Steel, Polyvinyl Alcohol, and Polyethylene Fibers on Slag–Yellow River Sediment Geopolymers

Steel fibers (STs), polyvinyl alcohol fibers (PVAs), and polyethylene fibers (PEs) were selected to systematically investigate the effects of different fiber types and dosages on the workability (slump and spread) and mechanical properties (compressive strength and splitting tensile strength) of slag–Yellow River sand geopolymer eco-cementitious materials. By combining microstructural testing techniques such as thermogravimetric-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), the influence mechanisms of fibers on the characteristic products and microstructure of the matrix were thoroughly revealed, and the role of fibers in the strength development of Yellow River sediment-based geopolymers was elucidated. The results show that as the fiber content increases, the workability of the mixture significantly decreases. The appropriate incorporation of steel fibers and PVAs can significantly enhance the strength and toughness of the matrix. When the fiber dosage is 1%, the 28-day compressive strength of specimens with steel fibers and PVAs increased by 25.93% and 21.96%, respectively, compared to the control group, while the splitting tensile strength increased by 50.00% and 60.34%, respectively. However, the mechanisms of action differ significantly; steel fibers primarily enhance the compressive performance of the matrix through their high stiffness and strength, whereas PVAs inhibit crack propagation through their flexibility and excellent bonding properties. In contrast, the strength improvement of PEs is mainly reflected in toughening. When the fiber dosage is 1.5%, the 28-day splitting tensile strength of PE specimens increased by 72.61%, and the tensile-to-compressive ratio increased by 92.32% compared to the control group. Microstructural analysis indicates that the incorporation of different types of fibers does not alter the types of characteristic products in alkali-activated cementitious materials, but excessive fiber content affects the generation of gel-like products and the distribution of free water, thereby altering the thermal decomposition behavior of characteristic gel products. Additionally, the matrix incorporating PEs forms a honeycomb-like amorphous gel, resulting in weak interfacial bonding between the fibers and the matrix. This is one of the main reasons for the limited reinforcing effect of PEs at the microscopic scale and a key factor for their inferior long-term performance compared to steel fibers and PVAs. This study provides theoretical foundations and practical guidance for optimizing the performance of fiber-reinforced geopolymer materials.

The effect of cations and metakaolin on chloride binding properties of mortars using simulated desalinated sea sand

With the scarcity of river sand resources, sea sand is also increasingly being used to prepare cementitious materials. Considering the threat of chloride salts still present in desalinated sea sand, this study investigates the effect of Na+, Mg2+, Ca2+ (contained on the surface of simulated desalinated sea sand) and metakaolin (MK) additions on the chloride binding properties of simulated desalinated sea sand mortar. The chloride binding capacity of the mortar and the hydration products of the mortar were analysed by chloride content measurement, X-ray diffraction, differential thermogravimetry, Fourier transform infrared spectroscopy and energy dispersive spectroscopy. The results show that Ca2+ and Mg2+ have a greater positive effect on improving the chloride binding capacity of mortar than Na+. This is because Ca2+ promotes the positive potential of the C–S–H gel in the mortar and Mg2+ facilitates the generation of a solid solution of Friedel’s salts and AFm in the mortar. The addition of MK in mortar improves the physical binding ability of the mortar to chloride ions. This improvement is primarily attributed to the increased production of C–S–H gel and C–A–S–H gel resulting from the addition of MK. This study is expected to provide theoretical support to facilitate the application of desalinated sea sand.

Utilization of Coal Bottom Ash as a Natural Sand Replacement in Mortar Containing Fly Ash

The substantial generation of waste ashes from coal thermal power plants (CTP), particularly fly ash (FA) and bottom ash (BA), poses significant environmental challenges; meanwhile, the exhaustion of natural river sand for the construction industry is more serious. The study aims to explore the use of BA as a sand replacement and FA as a partial cement substitute in mortar production, focusing on sustainability. In this research, FA and cement served as binder materials, with FA comprising 15% of the total binder mass. BA was incorporated as a fine aggregate, replacing sand at varying levels of 0%, 25%, 50%, 75%, and 100% by weight. The study assessed the effects of BA substitution on the mortar's compressive strength (CS), ultrasonic pulse velocity (UPV), water absorption (WA), thermal conductivity (TC), and resistance to sulfate attack. Additionally, scanning electron microscopy (SEM) was utilized to analyze the mortar's microstructure. Results indicate that substituting sand with BA negatively impacted all tested properties. As BA content increased, CS, UPV, and TC of mortar samples decreased, while WA and sulfate expansion increased markedly. At 56 days, the mortar samples exhibited CS values ranging from 20.6 to 57.0 MPa, UPV values from 3395 to 4203 m/s, WA values from 5.58% to 18.70%, and TC values from 0.89 to 1.73 W/m·K. Furthermore, the control mortar demonstrated a length change of 0.0218% due to sulfate attack, whereas the length changes for specimens with 25%, 50%, 75%, and 100% BA replacement were approximately 68.8%, 96.3%, 155.0%, and 162.4% higher, respectively.

Durability characteristics of geopolymer concrete produced using gold ore tailings along with recycled coarse aggregates

The Gold Ore Tailings (GOTs) are one of the major waste materials in the mining sector. The disposal of these tailings could be a problem for human health and a major environmental concern for several years. In this research work, the GOTs were used as an alternative material to the River Sand (RS) in the production of Geopolymer Concrete (GPC). Thus developed GPC samples were tested for its durability characteristics, such as resistance to sulphates and chlorides. The sulphate attack test was conducted by immersing the Conventional Concrete (CC) and GPC samples in 5% Magnesium Sulphate (MgSO4) solution for various curing periods. In this test, the GPC samples showed a reduction in compressive strength and weight, which is slightly more when compared to CC samples. The Rapid Chloride Penetration Test (RCPT) was also conducted to know the chloride ion penetration in which GPC samples exhibited less chloride penetration when compared to CC samples. Further, the Toxic Characteristic Leaching Procedure (TCLP) analysis showed that the GOTs have very high concentrations of hazardous metals. However, the concentration of Cyanide (CN−) was minimal in GOTs. In this regard, geopolymerization would be a better method for immobilizing the hazardous metals in GOTs.

Experimental study on the mechanical properties of lightweight aggregate concrete mixed with fly ash and shells

In this study, lightweight aggregate concrete [LWAC] was prepared by partially replacing cement with fly ash and partially substituting river sand with shell. The effects of fly ash and shell on the mechanical properties of concrete were studied by compressive test, splitting tensile test and flexural test. In addition, the specimens were microscopically analyzed by SEM electron microscopy. The results showed that both the compressive strength and splitting tensile strength decreased gradually with the increase of fly ash replacement ratio, but the maximum reduction was only 1.4 % and 3.1 % when the fly ash substitution ratio was 5 %. With the increase of shell replacement ratio, the compressive strength and splitting tensile strength of concrete increased first and then decreased, reached their maximum value at a substitution ratio of 10 %. The optimum fly ash substitution ratio and shell replacement ratio for LWAC were 5 % and 10 %, respectively. The compressive strength, splitting tensile strength and flexural strength of the experimental group under the optimum substitution ratio increased by 2.7 %, 0.6 % and 4.6 %, respectively, compared to the control group. The correlation coefficients of compressive strength with split tensile strength and flexural strength were 0.91 and 0.82, respectively. Finally, a compressive strength calculation formula related to fly ash substitution ratio and shell replacement ratio was proposed based on the Bolomy formula, and the correlation coefficient between the calculated value and the experimental value was 0.91.

Influence of Microbially Induced Calcite Precipitation Technique on Mitigating Rainfall-Induced Surface Erosion of the Ganga River Sand

Influence of Microbially Induced Calcite Precipitation Technique on Mitigating Rainfall-Induced Surface Erosion of the Ganga River Sand

Detrital zircon geochronology of river sands from the Salween River: Implications for sedimentary provenance and erosion pattern

Detrital zircon geochronology of river sands from the Salween River: Implications for sedimentary provenance and erosion pattern

Characteristics Of Saddang River Sand, Pinrang Regency, South Sulawesi, Indonesia Based On Grain Gradation, Mud Content And Specific Gravity

The research aims to determine the characteristics of sand grain gradation, mud content and specific gravity of Saddang River sand. Saddang river sand is the main source of sand used in construction activities in South Sulawesi and West Sulawesi. In order to ensure that Saddang river sand meets the quality standards used in the construction world, it is necessary to conduct research related to Gradation of grains, mud content and specific gravity of sand. These three factors are part of the factors that determine the quality of concrete and cement mixtures. The research was located at the Saddang River sand mine in Pincara Village, Patampanua subdistrict, Pinrang Regency, South Sulawesi, Indonesia. The research method uses field surveys and laboratory analysis to analyze the gradation of sand grains, mud content and specific gravity. The results of the sieve analysis show that the Saddang River sand is classified as gradation zone no. 4 or classified as fine sand based on the fine aggregate gradation table SNI 03-2834-2000 and ASTM C-33. The results of the analysis of the Saddang River sand mud content ranged from 2.233% to 2.250%, fulfilling SNI 03-4804-1998 which has been determined at a maximum of 5%. The specific gravity analysis show the average value of bulk specific gravity (2,489 gr/m3), dry specific gravity (2,524 gr/m3), and visible specific gravity (2,600 gr/m3). meets SNI 03-1970-2008 standards ranging from < 1.6 gr/m3 to 3.2 gr/m3. The ater absorption in fine aggregate ranged from 1.5% to 3.8%, meeting SNI 03-1970-2008 with a maximum of 5%.

A Review on the Recycling of Spent Garnet as a Mixing Ingredient in Concrete

Construction industry has increased rapidly leading to increase in concrete usage. This contributes to its limitation of natural resources and issue of sand shortage in certain place. This problem primarily due to the uncontrolled river sand mining. The demand for eco-friendly construction methods has driven research into substitute materials for conventional sand, and aggregates. Thus, embracing industrial by-products known as spent garnet as alternative materials presents an appealing solution to mitigate reliance on sand resources, thereby contributing to the sustainability of river ecosystems. Spent garnet is a waste derived from the surface treatment process in the shipping industry and is usually dumped in landfills. This review critically examines the viability of integrating spent garnet into construction materials. Comprehensive assessments of the physical and mechanical properties of these composite materials shed light on the potential improvements and challenges associated with the use of spent garnet. Ultimately, the review synthesizes the current state of knowledge on spent garnet in construction, offering valuable insights for researchers and industry professionals seeking innovative, sustainable solutions in materials science and waste management.

Palm fruit bunch fiber impact on compressive strength of cement mortar with different fine aggregate types

Depletion of high-quality natural sand deposits and sustainability concerns are popularizing manufactured sand use in cementitious composites. Meanwhile, palm fruit bunch fiber (PFBF) improves the properties of cementitious composites, but it is unclear how PFBF interacts with different fine aggregates to affect mortar strength. This study investigated the impact of PFBF on the compressive strength of cement mortars containing manufactured sand (granite quar- ry dust) and natural sands (river and pit). The aggregates were used with Portland cement to fabricate mortar cubes, which were tested after 28 days. The control mortars (0% PFBF) of quarry dust, river sand, and pit sand recorded strength of 24.2 MPa, 21.5 MPa, and 10.4 MPa, respectively. At the optimum fiber content, the strength of the quarry dust and pit sand mor- tars increased marginally to 24.7 MPa and 12.2 MPa, respectively. However, river sand mortar strength considerably increased to 26.1 MPa. Interestingly, the quarry dust and pit sand mortars generally experienced strength loss before reaching their peak at 2.0% and 2.5% fiber content, respectively. In comparison, river sand mortar consistently gained strength before peaking at 2.5% PFBF. Hence, pre-optimum fiber contents could enhance river sand mortar strength but hinder quarry dust and pit sand mortar strengths. By standardizing the PFBF-reinforced mortar strengths against the control strengths, PFBF enhanced pit sand mortar strength the most, fol- lowed by river sand mortar, but it mainly reduced quarry dust mortar strength. Mortar design must, therefore, optimize PFBF dosage considering the unique characteristics of each sand type.

An Experimental Study on the Performance of Strength of Concrete by Partial Replacement of Cement by GGBS and Complete Replacement of Sand by M-Sand

Concrete is the most widely used material in the construction industry. Possessing high strength and stability, concrete is also an economical building material. Cement required in the concrete leaves enormous carbon foot print which shows an alarming impact on the global environmental conditions. Hence, there is a requirement of some material which can be effective in supporting cement when added along with it shows similar characteristics. Due to increased construction and infrastructure activities, we are consuming more quantity of concrete and hence we are consuming more energy in the extraction of mineral ores for the production of cement concrete. This in turn is contributing more production of carbon elements which is a challenge for the sustainable development. Hence, there is a need of utilization of waste materials which are produced as byproducts in the industries which can replace cement, fine and coarse aggregates to some extent. Ground Granulated Blast Furnace Slag (GGBS) is found to be one such material which has similar characteristics when mixed with cement. GGBS is a waste material (byproduct obtained from iron industry) which is required to be disposed. Similarly, in recent days, the demand for river sand is increasing due to its lesser availability and environmental considerations. Also, there are stringent norms for the extraction of river sand which is coming under the category of mining which is creating environmental issues during the rainy season. M-Sand is obtained as byproduct from quarry industry which has similar properties and characteristics to that of river sand. Hence the practice of replacing river sand with M-Sand is taking a tremendous growth. The main objective of this study is to investigate the performance of strength characteristics of concrete by replacing cement and fine aggregates, to provide an economical and environmentally friendly concrete, to make use of waste materials in useful manner, to reduce the demand of cement and hence to promote green concrete, sustainable construction and sustainable development. In this project work, the strength characteristics of M30 grade concrete is analysed. Concrete cubes, beams and cylinders are casted for the normal concrete as well as concrete with GGBS and M-Sand. The cubes, beams and cylinders casted with the different proportions of cement, GGBS and River Sand / M-Sand are tested for the compressive strength at the end of 7, 14 and 28 days of curing, and split tensile strength and flexural strength at the end of 28 days of curing at room temperature. Based on the test results, the optimum percentage of GGBS was found.

Design and development of self-compacting alkali-activated concrete for energy-efficient building material

Anticipated urbanization and population growth, particularly in developing countries, are expected to boost demand for concrete, resulting in higher emissions and raw material consumption. In response to growing global sustainability awareness, various industries and countries have implemented diverse initiatives aimed at significantly reducing their greenhouse gas emissions. Alkali Activated Concrete (AAC), often known as zero cement concrete, is a viable substitute for conventional concrete. This study developed self-compacting alkali-activated concrete (SCAAC) using agro-industrial wastes and curing at ambient temperatures. The precursors were ground granulated blast furnace slag (GGBS) and fly ash (FA), which were activated with sodium hydroxide flakes and liquid sodium silicate. Co-fired bio-blended ash (BA), an agro-industrial waste, was used to partially replace river sand. The physical, chemical, mineral, and morphological properties of BA were thoroughly investigated. The BA was found suitable to use as a partial replacement for river sand in self-compacting alkali-activated concrete. The curing at ambient temperature was effective in producing a high-strength and durable concrete material. The thermal conductivity of the developed concrete was determined. The reduction in embodied energy for the developed material was calculated. The reduction in peak cooling load was found using computational modeling for cement based concrete and SCAAC. The developed concrete successfully met the specified compressive strength requirement for M30 grade concrete, achieving a value of 38.12 MPa. Reduction in embodied energy (7.37%) of the developed concrete was observed as compared to conventional concrete. Results show that the peak cooling load reduced by 35% compared to conventional concrete [1.9 W/(m.K)] due to the lower thermal conductivity of the developed material [1.247 W/(m.K)]. The use of agro-industrial wastes in the concrete mixture not only reduced the environmental impact but also utilized waste materials that would otherwise be disposed of in landfills. Overall, this study demonstrates the potential for sustainable and environmentally friendly construction materials using agro-industrial wastes.

Denudation rates and Holocene sediment storage dynamics inferred from in situ14C concentrations in the Feshie basin, Scotland

SummaryScotland's Highlands are tectonically quiescent but have experienced high rates of isostatic uplift in response to deglaciation. To understand the effects of both deglaciation and regional uplift on landscape evolution, we measured the concentration of cosmogenic in situ 14C in river sands collected in Glen Feshie (Cairngorms). Like other terrestrial cosmogenic radionuclides, in situ 14C can be used to calculate basin‐wide denudation rates over millennial timescales. 14C has a short half‐life relative to other in situ cosmogenic radionuclides, giving it an advantage in post‐glacial landscapes: Very little 14C will be inherited from exposure before glaciation of the landscape, meaning that concentrations will reflect sediment production and transport dominantly in the Holocene. When we calculate denudation rates based on the common assumption of basin‐wide homogeneity of erosion, we find no correlation between topographic metrics such as the normalised channel steepness index and inferred denudation rates, which range between 0.175 and 1.356 mm/year. Based on field and remote sensing observations, we suggest that 14C becomes diluted downstream due to sediment supply from paraglacial terrace material, and develop a mixing model to test this hypothesis. We identify the terraces that are likely to contribute sediment to the channels through flood modelling, geomorphic mapping and remote sensing observations. Our mixing model indicates that the observed distribution of 14C concentrations can be explained if terrace escarpments have basin‐averaged migration distances of 8 to 30 cm during large flood events. This interpretation is consistent with remotely sensed images of channel activity and terrace bank retreat within the catchment. Our results show that paraglacial sediment stores contribute to sediment fluxes in the late Holocene and highlight the on‐going glacial legacy on landscape evolution.

Nitrogen-Fixing Bacteria Promote the Growth of Fritillaria taipaiensis P. Y. Li by Regulating Physiological and Biochemical Reactions and Protecting Enzyme System-Related Gene Expression

The widespread application of chemical fertilizers and pesticides has resulted in environmental pollution. With the growing emphasis on ecological agriculture in traditional Chinese medicine, microbial fertilizers are increasingly recognized for their potential. The aim of this study is to investigate the effect of inoculating nitrogen-fixing bacteria on the soil (yellow loam, river sand, and organic fertilizer in a 2:1:1 ratio) of Fritillaria taipaiensis, with a focus on the leaf changes in terms of physiological parameters, antioxidant enzyme activity, and corresponding gene expression levels. The experiment involved three nitrogen-fixing bacteria, namely Rahnella aquatilis, Pseudomonas chlororaphis, and Paenibacillus stellifer, with a total of eight treatment groups. The objective was to assess how these bacterial treatments influenced physiological parameters, photosynthetic characteristics, pigment content, and both antioxidant enzyme activities and gene expression in the leaves of F. taipaiensis. The experimental results demonstrated statistically significant reductions (p < 0.05) in malondialdehyde (MDA) content and stomatal limitation value (LS) in F. taipaiensis leaves under treatment conditions relative to the control group (CK). The most substantial decreases were observed dual-inoculation with R. aquatilis and P. stellifer (N5), showing reductions of 38.24% and 20.94% in MDA and LS compared to CK values. Additionally, leaf area, leaf thickness, stem thickness, plant height, photosynthetic parameters, pigment content, soluble sugars, soluble proteins, proline levels, and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) exhibited varying degrees of increase. Compared to the CK group, the SOD, POD, and CAT activities of the N5 group increased by 141.06%, 160.59%, and 106.23%, respectively. The relative gene expression patterns of SOD, POD, and CAT corresponded with the trends observed in their respective antioxidant enzyme activities. Pearson correlation analysis further demonstrated that leaf area and net photosynthetic rate (Pn) were significantly correlated with respect to SOD, POD, and CAT activities, as well as their corresponding gene expression levels. In conclusion, inoculation with nitrogen-fixing bacteria improved the growth and stress tolerance of F. taipaiensis, with the combined application of Rahnella aquatilis and Pseudomonas stellifer yielding the most effective results. This study establishes that different rhizosphere nitrogen-fixing bacteria, either individually or in combination, influence the photosynthetic characteristics, physiological and biochemical parameters, and protective enzyme systems of F. taipaiensis. These findings provide a theoretical foundation for the selection of nitrogen-fixing bacteria as biofertilizers in the artificial cultivation of F. taipaiensis and highlight their potential application in the cultivation of traditional Chinese medicinal materials.

Governing Artisanal and Small‐scale Sand Mining in Bangladesh

ABSTRACTThis article uses an in‐country comparative approach to investigate the governance of artisanal and small‐scale river sand mining in Bangladesh, focusing particularly on sector heterogeneity, tax farming and power imbalances. It analyses sand governance in two diverse sand‐mining sites in Bangladesh — one mechanized and large, and the other manual and small‐scale. Drawing on in‐depth interviews and focus group discussions, the study reveals that the more mechanized site faced greater regulatory challenges due to its complex web of political and economic relations, contrasting with the simpler governance dynamics of the smaller site. The findings demonstrate that power distribution among stakeholders, including local administrations, leaseholders and miners, significantly shapes governance outcomes. Tax farming, whereby leaseholders but also administrations prioritize short‐term profits over sustainable practices, emerges as a critical issue. This research contributes to ongoing discussions about sand governance, advocating for a nuanced understanding of how the specific characteristics of mining contexts influence regulatory effectiveness. Ultimately, the study calls for a reform of leasing practices and governance models to improve sustainability and inclusivity in sand mining in Bangladesh and beyond. This work not only adds to the literature on artisanal and small‐scale mining but also emphasizes the importance of contextualized governance frameworks in sand resource management.

Modeling of sand-cultivated substrate for Gobi facility agriculture and validation of trenching test

Accurately simulating the interaction between trenching devices and river sand substrates is crucial for optimizing agricultural practices in Gobi Desert facility agriculture. This study calibrates Discrete Element Method (DEM) parameters for river sand substrate in the Gobi Desert of Northwest China, utilizing the Hertz-Mindlin contact model coupled with the Johnson-Kendall-Roberts (JKR) contact model in EDEM software. Key parameters, including stacking angle, particle size distribution, and morphology of the river sand, were measured using various methods and tools, such as an image acquisition system, vibration grading device, and stacking angle test apparatus. A model was developed to simulate the interaction between the river sand substrate and trenching device. The river sand matrix exhibited a stacking angle of 31.91°, with 9.85% of particles smaller than 0.25 mm, 52.60% ranging from 0.25 to 0.6 mm, and 37.55% exceeding 0.6 mm. A Plackett-Burman experimental design was employed to identify the sensitive parameters, including the static friction coefficient between river sand particles, the rolling friction coefficient of river sand and steel, and the restitution coefficient between river sands. The steepest ascent approach established the parameter ranges, and the Box-Behnken design (BBD) was used for optimization, resulting in the following parameter values: 0.533 for the static friction coefficient between river sand particles, 0.209 for the rolling friction coefficient of river sand and steel, and 0.213 for the coefficient of restitution between the river sand particles. A DEM model was developed based on these optimized parameters. Validation through experiments demonstrated that the simulation closely matched field test results, with errors in trench depth, surface width, and bottom width, all within a 9% margin of 8.8%, 4.8%, and 7.9%, respectively. These findings confirmed the accuracy and applicability of the DEM model for stimulating the interaction between river sand substrate and trenching equipment in Gobi Desert facility agriculture. This study provides a theoretical framework for optimizing trenching devices and rapidly constructing DEM models for river sand in sand farming systems.

Optimizing Concrete Properties with Stone Dust and Banana Peel Admixture

Concrete's widespread use has intensified the demand for river sand, leading to scarcity and environmental concerns. This project investigates stone dust and brick crusher dust as sustainable fine aggregate replacements in M35 concrete. Stone dust, a byproduct of quarrying, and brick crusher dust, from construction waste, offer viable alternatives. The study aims to evaluate their impact on concrete strength and workability. Replacing river sand with stone dust (0%, 50%, 60%, 70%) demonstrated a 10% increase in compressive and tensile strength up to a 60% replacement. Additionally, brick crusher dust shows potential as a cost-effective, eco-friendly fine aggregate. Furthermore, dried banana peel powder (DBPP) is explored as a natural admixture. Its cellulose content may enhance workability and reduce shrinkage, offering a sustainable alternative to synthetic additives. However, proper treatment is essential for durability. This research highlights the effectiveness of stone dust and brick crusher dust as fine aggregate replacements, maintaining design strength while promoting waste utilization. The incorporation of DBPP presents an innovative approach to sustainable concrete production. This project aims to contribute to eco-friendly construction practices by demonstrating the viability of these alternative materials Key Words: Compressive strength, Durability, Workability improvement, Waste material utilization, Eco-friendly construction.

Wetland plant growth in recycled glass sand versus dredged river sand: evaluating a new resource for coastal restoration

Wetland plant growth in recycled glass sand versus dredged river sand: evaluating a new resource for coastal restoration