Crushed Stone Research Articles

Enhancing blasting efficiency: A smart predictive model for cost optimization and risk reduction

Mineral extraction involves distinct stages, including drilling, blasting, loading, transporting, and processing minerals at a designated facility. The initial phase is drilling and blasting, crucial for controlled dimensions of crushed stone suitable for the processing plant. Incorrect blasting can lead to unsuitable stone grading and destructive outcomes like ground vibrations, stone projection, air blasts, and recoil. Predicting and optimizing blasting costs (BC) is essential to achieve desired particle size reduction while mitigating adverse blasting consequences. BC varies with rock hardness, blasting techniques, and patterns. This study presents a BC prediction model using data from 6 Iranian limestone mines, employing firefly (FF) and gray wolf optimization (GWO) algorithms. With 146 data points and parameters like hole diameter (D), ANFO (AN), sub-drilling (J), uniaxial compressive strength (σc), burden (B), hole number (N), umolite (EM),spacing (S), specific gravity (γr), stemming (T), hole length (H), rock hardness (HA), and electric detonators (Det), the data was split into 80% for model construction and 20% for validation. Using statistical indicators, the model showed good performance, offering engineers, researchers, and mining professionals high accuracy. The @RISK software conducted sensitivity analysis, revealing T parameter as the most influential input factor, where minor T changes significantly affected BC. Lastly, the @RISK software was employed to conduct a sensitivity analysis on the model's outputs. The analyses demonstrated that, among the input factors, the T parameter had the most pronounced effect on the model's output. Even small changes in the value of T led to considerable fluctuations in the predicted BC.

Optimizing decarbonation and sustainability of concrete pavement: A case study

This study focuses on the actual project of rural road ‘concrete to asphalt’ pavement renovation, deeply integrating the design concept of full structure regeneration and the innovation of in-situ regeneration technology for old cement pavement. Through the life cycle assessment method, an environmental impact quantification assessment model is used. Based on the analysis of the environmental benefits of traditional pavement renovation technology (using multi-hammer crushed stone and hot mix asphalt production technology), the environmental advantages of the full-structure regeneration technology scheme are outlined, including the recycling of recycled asphalt pavement materials, application of emulsified asphalt plant mixing cold regeneration technology, and implementation of resonance crushed stone on-site regeneration technology. At the same time, sensitivity analysis methods are used to deeply analyze the sensitivity of changes in parameters such as surface and base thickness, transportation distance, and environmental factors to the overall environmental impact. The research results indicate that the optimization plan can achieve a 57.97 % reduction in total energy consumption and a 71.45 % reduction in total carbon emissions. Additionally, the recycling and utilization of RAP materials significantly reduce the demand for new mineral materials and asphalt. For a 1-kilometer road surface, mineral materials save up to 82.39 % and asphalt saves up to 27.11 %. The energy consumption and carbon emissions generated during the raw material production stage in both schemes contribute the most to the environmental impact of road construction. The analysis found that the environmental benefits of the optimization plan mainly come from the recycling of the old cement concrete pavement as the base layer after resonance crushing, as well as the use of emulsified asphalt mixture cold recycling instead of the lower layer of hot mix asphalt concrete, achieving full-scale recycling of the pavement renovation. The relevant findings provide a data foundation or the improvement and upgrading of energy-saving and emission reduction technologies in road surface renovation and offer valuable insights for future research on sustainable road surface renovation strategies.

Study of the microstructure of asphalt concrete using X-ray computed tomography

A mechanical digital twin (a mechanical finite-element model) of an asphalt concrete sample has been developed in the framework of a project for recycling polymer composite materials with fibrous reinforcement (fiberglass) as an alternative for crushed stone in the asphalt concrete production. A methodology of using X-ray computed tomography (XCT) for analysis of the asphalt concrete microstructure and calculation of the mechanical properties is developed. The data processing chain for developing a digital twin of the asphalt concrete microstructure, based on X-ray micro-computed tomography (XCT) image includes the following steps: 1) image enhancement; 2) image segmentation; 3) analysis of the morphology of pores and solid particles; 4) transformation of the segmented image into a voxels-based finite element (FE) model. It is demonstrated that the XCT resolution of 40 μm is sufficient for a reliable identification of microstructural parameters, i.e., volume fractions of the components, distributions of voids (pores) in size, shape and spatial position, as well as distributions of the crushed brittle additives (fiberglass chips) in size. The FE model constitutes a digital twin of the material, and, after specifying the characteristics of the material components, can be used for simulation of the thermomechanical and functional properties of the material. The developed procedure is exemplified in the calculation of statistics of the compression and shear moduli of the asphalt concrete with addition of crushed fiberglass particles. The dependence of the calculated elastic properties on the size of the digital twin is studied. It is shown that a model size of 10 mm and more is sufficient for the microstructural representativity and calculation of the homogenization characteristics. The results can be used for analysis of the microstructure and structure-dependent thermomechanical properties of asphalt concrete. The developed finite element model can be used for modelling of the visco-elastic response of asphalt concrete and its behavior under cyclic loading.

A Large-Scale Cross-Sectional Study On Respiratory Health, Lung Function Impairment, And Radiological Assessment Of Stone Crushing Workers In Pakistan

A Large-Scale Cross-Sectional Study On Respiratory Health, Lung Function Impairment, And Radiological Assessment Of Stone Crushing Workers In Pakistan

Utilization Of Sugarcane Bagasse Waste As Green Concrete Using Local Aggregate

Waste in the form of sugarcane bagasse which is processed by burning to turn it into ash has the same content as the main ingredients that make up Portland cement, namely silica (SiO2) and ferrite (Fe2O3), so that sugarcane bagasse ash can be used as a pozzolan which, apart from replacing some of the cement, can also increase the compressive strength of concrete. . The research method is testing concrete making materials and sugarcane bagasse ash. Tests were carried out for variations in the addition of sugarcane bagasse ash at 0%, 3% and 5%. The fine aggregate used in this research is fine coarse aggregate originating from Barito Sand. The coarse aggregate used in this research is coarse aggregate measuring 10 – 20 mm cotton crushed stone originating from Barito Kuala. The results of the concrete mix are made according to SNI 03-2834-2000 regarding the calculation of concrete mix planning (mix design). From the test results, it was found that the materials used, such as water, cement, sugarcane bagasse ash from Landasan Ulin and coarse aggregate crushed stone, 1-2 crushed cotton stones from Barito Kuala, can be made for a concrete mix proportion of K-250 kg/quality. cm2 varies starting from 0% or normal concrete, 3% bagasse ash and 5% bagasse ash.

Effect of Polypropylene Fibre on Self- Compacting High-performance Concrete

This study conducted tests on the design mixture of Polypropylene Fibre Reinforced Self-Compacting High-performance Concrete (PFRSCHPC) and Self-Compacting high-performance concrete (SCHPC) to determine the mechanical properties of the concrete, and the beams behaviour under bending loads. The composition of the mixtures of PFRSCHPC and SCHPC refer to Oesman, et al. (2022), which conducted research on UHPC (ultra-high-performance concrete) using natural sand and crushed stone through a 4.75mm sieve. PFRSCHPC and SCHPC compositions using Portland Slag Cement (PSC); 1% superplasticizer and 30% silica fume of the total binder; 1% Polypropylene fibre (PP); the ratio of� sand to crushed stone 45%: 55%; and the w/b was 0.23. However, SCHPC as the control concrete mixture does not contain PP. The testing results of the PFRSCHPC showed compressive strength, tensile strength, flexural strength, and modulus of elasticity were 42.73 MPa; 4.33 MPa; 8.98 MPa; 45.51 GPa, respectively. When compared to SCHPC, PP has an influence in increasing tensile strength by 2.38 MPa (122.05%), flexural strength by 2.67 MPa (42.77%), and concrete elasticity modulus by 6.67 GPa (17.32%). However, 1% PP decreased compressive strength of PFRSCHPC, lower by 4.93 MPa (10.34%) compared to SCHPC. PFRSCHPC beam reached a peak load of 27.5 kN; initial stiffness of 5.32 kN/mm; ductility of 5.6; and toughness of 1606.08 kNm. PFRSCHPC beam with PP fibre content of 1% are able to increase 17.02% of peak load; 14.75% of ductility, and 113.91% of toughness.

The Application of MgO-Modified Biochars for the Immobilization of Ni, Cu, Pb, and Cr in Stone Crushing and Mining-Polluted Soil

The objective of the present study was to investigate the impact of MgO 0.5 g/kg loaded in different organic waste materials on the properties of the modified biochars obtained. The waste materials included tea waste, wood waste, water chestnut peel, and pomegranate peel, which were used to create tea waste MgO-modified biochar (TWMgO-MBC), wood waste MgO-modified biochar (WSMgO-MBC), water chestnut peel MgO-modified biochar (WCMgO-MBC), and pomegranate peel MgO-modified biochar (PPMgO-MBC). All the MgO-modified biochars were prepared at 600 °C for 2 h and applied at 0.5 and 1% doses for the immobilization of Ni, Cu, Pb, and Cr in stone crushing and mining-polluted soil and the reduction in their uptake by pearl millet (Pennisetum glaucum) plant. The greatest fresh and dry biomasses were observed at 45.04% and 31.29%, respectively, with the application of TWMgO-MBC 1% in stone-crushing-polluted soil. The highest degree of immobilization of Ni (76.67%) was observed for the WSMgO-MBC 1% treatment, Cu (73.45%) for WCMgO-MBC 1%, Pb (76.78%) for WSMgO-MBC 1%, and Cr (70.55%) for WCMgO-MBC 1%, in comparison with the control. The maximum uptake of Ni, Cu, Pb, and Cr in the shoot of pearl millet was reduced by 78.43% with WSMgO-MBC 1%, 75.06% with WSMgO-MBC 1%, 90.81% with WCMgO-MBC 1%, and 85.71% with WSMgO-MBC 1% as compared with the control. The greatest reduction in Ni, Cu, Pb, and Cr in the root of pearl millet was observed at 77.81% with WSMgO-MBC 1%, 68.09% with WCMgO-MBC 1%, 84.03% with WCMgO-MBC 1%, and 88.73% with WCMgO-MBC 1%, in comparison with the control. The present study demonstrated that the TWMgO-MBC 1% treatment was highly effective for improving plant growth, while the WSMgO-MBC 1%, and WCMgO-MBC 1% treatments were found to be highly effective for immobilizing heavy metals in polluted soils, thus facilitating safe crop cultivation. Future studies should concentrate on the long-term application of MgO-modified biochars for the remediation of multimetal-polluted soils.

Exploring Silico-tuberculosis: A Detailed Investigation of 45 Cases in Occupational Settings

Objective: Silicosis is a lung disease caused by inhaling crystalline silica dust, leading to inflammation and scarring of lung tissue. This retrospective study investigates the association between silicosis and tuberculosis (TB) in occupational settings, analyzing 45 male silicosis patients at Ibn Rochd University Hospital in Casablanca from June 2003 to December 2023. Cases: The average duration of occupational exposure was 18 years, primarily in well-digging, stone crushing, mining, and masonry. Clinical symptoms included dyspnea (89%), persistent bronchial syndrome (83%), and hemoptysis (54%). Imaging typically revealed pseudo-tumoral opacities, often with associated mediastinal lymphadenopathy and micronodular or excavated opacities. TB diagnosis was confirmed by GeneXpert (23% in sputum, 70% in bronchial aspirate fluid) and culture (7%). Conclusion: Anti-tuberculous treatment led to clinical improvement in most cases, but there were two deaths from acute respiratory failure and one case of TB relapse. The findings underscore the importance of screening and chemoprophylaxis for TB in managing silicosis. Preventive measures and worker health protections are crucial to reduce the incidence of silicosis and its complications.

Properties of recycled coarse aggregates obtained from crushed concrete waste

According to the Kyiv School of Economics as of January 2024, the losses from the destruction and damage of buildings and structures as a result of military actions in Ukraine amount to at least 75 billion dollars. Now contractors carrying out the liquidation of the consequences of armed aggression are required to take measures to reuse construction waste. Taking into account the presence of natural crushed stone in concrete scrap, the question arises about the possibility of using crushed concrete in new construction. During the design a concrete mixture it is necessary to know such characteristics of aggregates as grain size composition, bulk density, specific density, voids, strength.Three mixtures of concrete were designed and aseries of cube samples were made from them to determine the specified characteristics of recycledcoarse aggregate obtained from crushed concrete on local materials. At the appropriate age the samples of origin concrete were crushed using a laboratory jaw crusher.The results of sieve analyses showed that ungraded mixtures of fine and coarse fractions do not meet the requirements of national standard due to the large content of coarse fractions. At the same time, in general, the granulometric composition of only coarse fractions meets the requirements of standards in Ukraine. The obtained bulk densities and specific densities differ in different fractions with a large dispersion even within the same fraction. The strength of the aggregate decreases with a decrease in grain sizes. Thus, the main factor that has a decisive influence on the properties of RCA and concrete with their use is the presence of residual mortar. The smaller the fraction of the RCA, the higher the residual mortar content, up to individual grains that are entirely composed of it. Therefore, one of the methods of improving the properties of RCA is to reduce the content of the residual mortar.

Manufacturing Environmentally Friendly Hollow Blocks using Different Aggregates: Effect on Mechanical Properties

Hollow concrete block (HCB) is one of the most fundamental materials in building and construction worldwide. Therefore, HCB has emerged as a viable alternative to traditional building materials likebrick. It is an excellent choice for constructing walls, pavements, and other masonry work construct a long-lasting structure. Today's new world requires a green, eco-friendly, and sustainable world, and HCB can play a significant role in achieving that goal. HCB has superior thermal and fire resistance properties, greater strength, cost-effectiveness, and eco-friendliness. Only a small amount of construction in Bangladesh is done using HCBs. However, as sustainable structural technology advances, more frequent use of HCBs will be required. As a result, this article will provide a brief overview of the various applications of HCBs in Bangladesh, including the manufacturing process and its benefits and drawbacks. Specifically, this work investigates and compares the effect of different natural fine aggregates collected from different areas of Bangladesh on the mechanical properties of HCB. The fine aggregates used in this study came from the Dharala, Patgram, Lalmonirhat, and Someshwari rivers in Durgapur, Netrokona, Bangladesh. HCBs were manufactured using a hydraulic press machine and were constructed using mix design ratios of 1: 5: 1: 3 (Cement: Gravel Sand: Sylhet Sand: Crushed Stone), 1: 4.17: 1.67: 1.5 (Cement: Gravel Sand: Sylhet Sand: Crushed Stone), 1: 2.33: 2: 1.33 (Cement: Gravel Sand: Stone Dust: Crushed Stone), 1: 3.33: 2.33 (Cement: Gravel Sand: Stone Dust) and 1: 2.5: 1: 0.50 (Cement: Gravel Sand: Stone Dust: Crushed Stone) with water cement (W/C) ratio of 0.37. The specimens' dimensions were chosen to be 390 mm x 190 mm x 100 mm. The specimens were tested for unit weight, water absorption, compressive strength, and tensile strength after 28 days of water curing. The results showed that HCBs made with different fine aggregates from the Dharala, Patgram, Lalmonirhat, and Someshwari rivers in Durgapur, Netrokona, Bangladesh, have different compressive strengths at 28 days, namely 978 PSI, 1604 PSI, 1267 PSI, 1162 PSI, and 2128 PSI. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 12(2), 2023, P 153-158

Radiation shielding properties of shotcrete containing different aggregates

In this study, the physical and mechanical properties of wet mix shotcrete produced using crushed stone aggregate (CS), ferrochrome slag aggregate (FS), and barite (B) aggregate have been investigated. Furthermore, the radiation shielding properties have been determined experimentally, theoretically, and through simulation. A control sample was produced using 50 % CS and 50 % FS. Subsequently, shotcrete groups were produced by substituting B aggregate at replacement rates of 25 %, 50 %, 75 %, and 100 % instead of FS. The mechanical properties such as density, ultrasonic pulse velocity (UPV), compressive strength, flexural strength, and splitting tensile strength of the produced spray concrete groups were investigated. Additionally, experimental radiation shielding measurements were conducted using a high-purity germanium (HPGe) detector system with emissions from four different radioactive sources (133Ba, 137Cs, 60Co, and 22Na) spanning nine different gamma energies ranging from 276.5 to 1332.5 keV. As a result of the experimental measurements, the linear attenuation coefficients (μ) of the shotcrete samples were obtained. A proportional increase in μ was determined with increasing barite content. Using the experimental mass attenuation coefficient (μ/ρ) results, half-value layer (HVL) and tenth-value layer (TVL) thicknesses, as well as mean free path (MFP) values, were calculated. An increasing B aggregate ratio did not have a significant effect on the μ/ρ value, while an increase was observed in the HVL, TVL, and MFP values. Moreover, the WinXCOM interface was employed for theoretical calculations, and the FLUKA Monte Carlo code was utilized for simulation calculations. The obtained data were compared with experimental results, revealing a good agreement between them. Based on the obtained data, it was concluded that increasing the B aggregate ratio resulted in improvement in mechanical properties compared to the control sample, and additionally, it was determined that B aggregate-added shotcrete is an effective gamma radiation shielding material.

Evaluation of As, Cd, Ni and Se Content of Some Mineral Concrete Agents

In this study, the variation of arsenic (As), cadmium (Cd), nickel (Ni) and selenium (Se) concentrations in some materials used as concrete admixtures were evaluated. These heavy metals are extremely hazardous elements for both human and other living organisms and the environment. Due to these hazards, they are on the priority pollutant list of both ATSDR and EPA. Study results show that heavy metal concentrations in some additives are at very high levels. As a result of the study, the highest As concentrations were obtained in copper slag, vermiculite and cem III cement, the highest Cd concentrations in crushed stone and copper slag, the highest Ni concentrations in copper slag, wood ash and brick powder, and the highest Se concentrations in blast furnace slag and cem III cement. This may pose a great risk to the health of people working in the industry and the environment.

Optimization of pre-grouting construction and evaluation of grouting effect in a deeply buried silt-filled shield tunnel

Controlling strata deformation during shield tunneling beneath unconsolidated soil layers poses a significant challenge in engineering construction. Limited research exists on optimizing pre-grouting mechanisms for shield tunnels in unconsolidated soil layers and controlling strata deformation. Therefore, conducting on-site optimization experiments for pre-grouting is crucial for controlling strata deformation. The paper employs crushed stone aggregate as a basis for modifying the shield jacket material. The primary method of verifying grout strength involves direct detection of foundation bearing capacity using a heavy-duty probe inside the tunnel. The feasibility of the comprehensive evaluation scheme is further confirmed through a combination of multi-point core sampling, five-point water pressure tests, and on-site shield monitoring data. The research results indicate that this technology effectively enhances the stability of deep-buried weak strata. By improving the physical and mechanical properties of backfill soil through a combination of crushed stone-cement slurry-soil skeleton, the self-stabilizing ability of surrounding rock is enhanced, and strata deformation is controlled. Additionally, a set of pre-grouting reinforcement and evaluation techniques suitable for deep-buried weak strata is proposed, providing valuable references for similar projects.

ASSESSMENT OF THE POSSIBILITY OF USING RECYCLED COARSE AGGREGATE IN A WOOD-SOIL CONCRETE SLAB

Problem statement. During the process of post-war reconstruction in Ukraine, there will be a need for a large number of affordable and ecological building materials, especially in the part of restoration and construction of low-rise buildings. Such building materials can be soil-concrete and aggregates from crushed concrete waste. The proposed constructive solution of the ribbed floor, in which the ribs are made of pine beams and OSB sheets, and the slab part is made of soil concrete on fixed formwork. The purpose of the article is to determine the optimal composition of the soil-concrete mixture using crushed stone obtained after crushing concrete scrap, taking into account the configuration of the wood-soil concrete slab, to determine the strength of soil-concrete of this composition, to determine the possibility of using recycled coarse aggregates. Conclusions. Based on the results of determining the optimal composition of soil-concrete, it was established that the maximum compressive strength is achieved when the mass content of the binder in the cement-soil mixture is at the level of 20 %. Taking into account the configuration of the slab part of the floor, a fraction of 5...7.5 mm is accepted for coarse aggregate. During the test of soil-concrete samples with recycled aggregate with a mass content of 10 %, 20 % and 30 %, the compressive strength of soil concrete decreased. Obviously, the presence of a clay component (loam) in the mixture reduces the adhesion in the contact zone between the aggregate and the soil-concrete, which increases the heterogeneity of the entire structure of the soil-concrete. Thus, the use of natural or recycled coarse aggregates in soil-concrete is impractical. Taking into account the determined strength of soil-concrete without aggregate, a scheme of combined concreting of the soil-concrete slab is proposed – heavy concrete above the rib and soil-concrete in the overhangs. In this case, there is a need for research on the possibility of using recycled coarse aggregate of the required size in heavy concrete.

Researching and Evaluation of Thermal Properties of Foamed Glass Crushed Stone in Conditions of Problem Soils

Researching and Evaluation of Thermal Properties of Foamed Glass Crushed Stone in Conditions of Problem Soils

Mixture composition design of magnesium oxychloride cement-stabilized crushed stone materials applied as a pavement base

Conventional binding materials, such as silicate cement and lime, present high energy consumption, pollution, and carbon emissions. Therefore, we utilize crushed stone as a stabilization material. Magnesium oxychloride cement (MOC) is modified and used as an inorganic admixture owing to its eco-friendly nature and low carbon content. We analysed the control indicators of an integrated design of MOC-stabilized crushed stone by conducting unconfined compressive strength and water-resistance tests. The optimum mixing composition of the MOC-stabilized crushed stone was determined through the response surface methodology. We determined the best approach and dosage for improving the water resistance of MOC-stabilized crushed stone by comparing the effects of four modification methods: fly ash, citric acid + silica fume, phosphoric acid + waterborne polyurethane, and dihydrogen phosphate potassium salt. We also perform a comparison with 5% ordinary silicate cement-stabilized crushed stone. The results indicate that the MOC-stabilized crushed stone exhibits a rapid increase in strength in the early stage, but this rate reduces after 28 days. The mixing design employs the 4-day unconfined compressive strength and 1-day water resistance coefficient as the technical indicators. The best mixing composition includes a 4.27% MOC dosage and a molar ratio of MgO/MgCl2 of 5.85. We use 1% citric acid + 10% silica fume in equal amounts to replace the MOC dopant method for composite modification of the MOC stabilized crushed stone. Consequently, the 1-day water resistance coefficient before water immersion is significantly increased from 0.78 to 0.91 and its 4-day unconfined compressive strength is only reduced by 0.10 MPa. This significantly improves the water resistance of the MOC-stabilized crushed stone and ensures that its strength remains unaffected, which is the optimal modification method. However, this method must ensure that a small amount of citric acid and silica fume are uniformly distributed in the MOC-stabilized crushed stone, which increases the construction difficulty of the road base.

Experimental evaluation of mechanical characteristics of concrete composites reinforced with jute fibers using bricks waste as alternate material for aggregates

In order to achieve high strength in concrete composites, various fiber reinforcements in plain concrete composites (PCC) are used. Steel is widely used for this purpose but the main issue in using steel as a reinforcement member is rusting, which results into structure deterioration. So, the alternative is to use a durable, environment friendly, and cost-effective natural fiber. Jute Fiber is used in this study for the reinforcement of plain concrete composites while, the plain concrete composites were made with cement, sand, and bricks waste. The comparative study of using bricks waste as an alternative material to crush bricks is also presented in this research study. Bricks waste and its disposal is becoming an environmental challenge. This study proposes jute fibers as a reinforcement element and uses bricks waste as an alternative material to crushed stone. M20 grade concrete with various volumetric percentages (0.05%, 0.10%, 0.25%, 0.50%, and 1.00%) of 10 mm long jute fibers are produced. An increase of 39% and 37% in compressive strength and split tensile strength, respectively, was observed after the addition of jute fibers. Therefore, the use of jute fibers and bricks waste to replace crushed stone is an effective way to mitigate environmental pollution and sustainability issues.

Mix Design and Field Detection of Large-Particle-Size Graded Crushed Stone Mixtures for Pavement Reconstruction

Large-particle-size graded crushed stone mixtures (LPS-GCSMs) can improve the shortcomings of conventional graded crushed stone, such as low strength, high deformation, and a low modulus of resilience. At present, there is no systematic research on the gradation design and field evaluation of the LPS-GCSMs. In this study, compaction and California bearing ratio (CBR) tests and field construction conditions were combined to design six kinds of gradation of LPS-GCSM, and the optimum gradation was revealed. In order to improve the mechanical properties of LPS-GCSM, 2.5% cement was added to the mixture to prepare a low-content cement-modified LPS-GCSM (LCC-LPS-GCSM) based on the suggested gradation. The mechanical properties of the LCC-LPS-GCSM were investigated through unconfined compression strength (UCS) and compression rebound modulus (CRM) tests. Moreover, the compaction and deflection properties of LPS-GCSM and LCC-LPS-GCSM were examined through the test battery. The results showed that the optimum gradation of LPS-GCSM can be achieved with a combination of aggregate sizes of 20–40 mm, 10–20 mm, 5–10 mm, and 0–5 mm at a ratio of 44:20:10:26. The passing rates of 19 mm and 4.75 mm should be approximately at the median value of the gradation in view of field construction uniformity and a coarse aggregate interlocking effect. The UCS and CRM values of LCC-LPS-GCSM increased rapidly from 0 day to 28 days while they slowed after 28 days, which was similar to those of cement-stabilized materials. The field detection suggested that LPS-GCSM exhibited favorable compaction and that the addition of cement improved the stability of the field compaction of the mixture. Adding a subbase course of LPS-GCSM between the old pavement and the LCC-LPS-GCSM base can lead to more uniform stress on the base. The results of this study provide a reference for the gradation design of LPS-GCSM and optimization of the design indicators.

Design and Fabrication of Atmospheric Dust Collector for Stone Crushers and Crematorium Units

This project aims at developing a machine for reducing the dust from stone crushers and crematorium unis. Most of the manufacturing industry faces significant challenges in the control of dust to ensure continued sustainable operation and to meet emissions regulations and goals. The methods for controlling dust emissions can either lie in the prevention of dust emissions or in the removal of dust once it has become airborne. Though the concept for dust collection system seems simple, many things can go wrong if don’t pay careful attention to the design details. Dust control systems involve multiple engineering decisions, including the efficient use of available space, the length of duct runs, the ease of returning collected dust to the process, the necessary electrical requirements, and the selection of optimal filter and control equipment. Further, key decisions must be made about whether a centralized or multiple system are best for the circumstances. Critical engineering decisions involve defining the problem, selecting the best equipment for each job and designing the best dust collection system for the needs of an operation. Well-designed dust collection systems need to consider not only the dust as a potential contaminant, but also the attributes of the dust capturing system. There are four key components in a dust collection system is very important like dust collector body, dust collector and the air mover/fan. This project helps to understand as a design guide which provides information that will help to achieve optimum performance and energy efficiency in commercial dust collection systems by properly selecting and sizing of dust collector and air blower or fan. A well-designed dust collection system has multiple benefits resulting in a dust-free environment that increases productivity, comply with emission regulations, and improve industry employee morale

Investigation of the Possible Correlations between Specific Characteristics of Crushed Stone Aggregates

This study rigorously investigates the interdependencies among a suite of crushed stone aggregate characteristics to enhance material selection for infrastructure projects. Utilizing data from Colas Északkő Ltd. (andesite quarries), the authors explore the relationships between mechanical and geometrical properties, particularly focusing on the interplay between the flakiness index, shape index, Los Angeles abrasion, Micro-Deval wear, and methylene blue assessments. The presented analysis reveals an unexpectedly robust correlation between FI and SI, proposing a novel paradigm for evaluating grain shape. Notably, the relationship between Los Angeles abrasion and micro-Deval wear values, typically considered disparate, is re-examined, unveiling potential predictive capabilities for environmental wear, especially as indicated by magnesium sulfate soundness testing. Additionally, the current study delineates a significant correlation between methylene blue values and micro-Deval wear performance, highlighting the intrinsic mineralogical influences on aggregate durability. The implications of findings are twofold: they suggest a streamlined approach for aggregate quality assurance and offer strategic insights into the refinement of material selection processes, thereby promising to enhance the durability and service life of transportation infrastructure.