Movement Of Material Research Articles

Effects of mandrel velocity on residual stresses created in cold expansion process of adjacent holes for AA6016-T6 and AA1100 aluminum alloys

Cold expansion is a mechanical method for creating residual stresses. This method is a proven technique to increase the fatigue life, and checking the residual stress on it, is of particular importance. A cold expansion process is widely used to generate beneficial residual stresses into an annular region around the hole. In the present research work, AA 6016-T6 and AA 1100 aluminum alloys which are two strain rate sensitive materials, were subjected to cold expansion process with different mandrel velocities. In fact, the effect of mandrel velocity on the created residual stresses has been investigated. The constants of the Johnson-Cook material model have been determined for them and the process has been investigated, experimentally and numerically. The obtained results revealed that the values of the residual stresses created in the sheets depend on the velocity of the process especially at the edge of the sheets holes. By increasing the mandrel velocity from 5 to 500 mm/min, depending on the distance from the hole to the edge of the sheet, it is possible to enhance the hoop residual stress by 37.3–41.2% in AA 1100 aluminum alloy and by 37.6–38.1% in AA 6016-T6 aluminum alloy. This research showed that in all cases, the radial residual stresses created around the holes are negative. Also, it was cleared that due to the existence of material constraints and the movement of the sheet material, the amount of hoop residual stress created in the mid-thickness is more than the exit face and in the exit face is also more than the entrance face, exactly unlike the size of their zones.

A Clinical Study on the Efficacy and Safety of Poly-Herbal Formulation in Managing Functional Dyspepsia

IntroductionFunctional dyspepsia is a common condition that affects millions of people worldwide. It is characterized by symptoms such as abdominal discomfort, bloating, and nausea, which can significantly impact a person's quality of life. While there are several pharmaceutical treatments available, many individuals are turning to herbal remedies as a safer and more natural alternative. This clinical study aimed to evaluate the efficacy and safety of poly-herbal formulation (PHF), marketed under brand names like Dizester® Herbal, Great Day®, etc. in patients suffering from functional dyspepsia compared to Pantoprazole, a commonly used pharmaceutical treatment. Materials & MethodsThe study included 80 patients, with 40 patients in each treatment arm. The primary objective was to assess the improvement in symptoms using various questionnaires at All India Institute of Medical Science Bhubaneswar, including the Reflux Disease Questionnaire, Short-Form Leeds Dyspepsia Questionnaire, GERD-Health Related Quality of Life Questionnaire, visual analogue scale (VAS) for pain, and Investigator's Symptomatic Assessment. The secondary objective was to evaluate the safety of PHF by assessing liver and renal function parameters and hemogram. Results & discussionThe results showed significant improvement in symptoms of GERD in the PHF group, which was comparable to the Pantoprazole group. The burning feeling behind the breastbone, pain behind the breastbone, burning feeling in the center of the upper stomach, acid taste in the mouth, and unpleasant movement of material upwards towards the mouth improved significantly from the beginning of the study to the follow-up visits. The mean VAS score reduced by 71.5% in the PHF arm and 67.85% in the Pantoprazole arm. Additionally, the study found no abnormal elevations in liver and renal function parameters in blood or any abnormal changes in hemogram, indicating the safety for use in patients with functional dyspepsia. Since the synthetic anti-dyspeptic drugs like proton pump inhibitors are known to have adverse effects, this natural alternative PHF shows promising results in a safer way. ConclusionIn conclusion, this study provides evidence for the efficacy and safety of PHF in improving symptoms of functional dyspepsia. The use of synthetic anti-dyspeptic medications has been associated with the occurrence of undesirable effects. In light of this, PHF has demonstrated encouraging outcomes in a manner that is considered safer.

Reiβscheiben ingots as markers of copper imports to the market of Medieval Novgorod

During the Middle Ages, massive ingots were the standard type of copper raw material obtained from European mines and exported across the Baltic and North Seas over vast distances. In Russian literature, they are known as “flat cakes” and “loafs”, while in the foreign one they are referred to as Reißscheiben (torn out disk). The article provides information about 24 cases of finding massive ingots. Most of the finds are concentrated on international trade routes and mark the main directions of movement of copper raw materials from mining operations located in the Western Carpathians, Erzgebirge and Eastern Alps, to the North and Baltic Seas. Recording and mapping of Reißscheiben that were not subject to remelting, and, therefore, retained the primary “isotopic marks”, provide valuable information for identifying sources of metal and establishing the routes of importing metal raw materials to the territory of medieval Rus. Huge volumes of copper shipwreck cargoes can be considered as reference samples when interpreting Pb-Pb data obtained for both different types of ingots and finished products.

An Analytical Review for Search of Optimal Selection & Utilization of Earthwork Equipment in Construction

Different types of equipment with various levels/times application times are the characteristic features of all construction projects. Almost every construction project/industry has the most common problem of slow progress and cost overruns due to increasing downtime and decreasing operational efficiency of construction equipment. Construction equipment is involved in construction to such an extent that without it no construction activity can be performed. In recent years, with the continuous advancement in technology and improvement of urbanization, there have been more and more construction project/equipment requirements resulting in either the project delay or cost enhancement As the most critical element earthwork is responsible for not only successful completion of project within schedule but also for the starting of the project, selection of right equipment for earthwork is necessary. Earthwork complexity further increases due to various soil types and equipment, and adverse environmental conditions The present study is concentrated or focused on soil and various costs based practices adopted for the selection of construction equipment and an attempt has been made to find the optimal solution for the most problematic or responsible activities for the delay in project/cost overrun especially in context to excavation, compression, and earth / material movement equipment utilization.

Genotyping-by-sequencing shows high genetic diversity in Corylus avellana germplasm resistant to eastern filbert blight

European hazelnut (Corylus avellana) is an anemophilous, dichogamous, self-incompatible tree nut species. It is native to a large portion of Europe, Turkey, and the Caucasus region, across which a wealth of plant genetic resources is present. The objective of this study was to evaluate the genetic diversity of a core set of C. avellana representing the world’s germplasm using genotyping-by-sequencing derived single nucleotide polymorphism (SNP) markers and to classify novel eastern filbert blight (EFB) resistant or tolerant accessions. Two-hundred-twenty-two accessions underwent next-generation sequencing (NGS) to generate SNP markers. From this, 1,250 SNP markers were used to construct a neighbor-joining (NJ) dendrogram and perform a STRUCTURE and discriminant analysis of principal coordinates (DAPC) analyses. In the dendrogram, five major groups were established, which generally corresponded to geographic origins of the plant materials studied. In STRUCTURE, support was found for groupings at (K) = 3, (K) = 6, and (K) = 10 populations, with the greatest Δ-(K) value occurring at (K) = 10. Although the three different analyses indicated slightly different solutions, the overall results were generally consistent from the standpoint of identifying similar accession groupings. For many of the accessions, recorded origins tended to correspond with their genetic grouping, although there was also evidence of intermixing and likely movement of plant materials. Interestingly, in all three analyses, a vast majority of the new accessions from the Republic of Georgia formed their own distinct group, highlighting this geographic region as a unique pool of C. avellana genetic resources. Overall, EFB resistant/tolerant accessions were placed across a wide range of genetic backgrounds. Thus, our results indicate EFB resistance/tolerance is present across a wide spectrum of C. avellana genetic resources, with the Georgian accessions representing a new and relatively unique germplasm pool that can be incorporated into hazelnut breeding programs.

Identifying and Managing Risks in High-Tech Supply Networks using Explainable Artificial Intelligence

Supply chains have become vital in enabling the smooth movement of material and information in the swiftly changing high-tech industries. By utilising technological innovations like automation and AI, supply chains may improve both safety and effectiveness at every level of the process, from manufacturing to sustainability. The necessity to adjust operations, give the adoption of technology top priority for resilience, and improve supply chain management efficiency. Transformation of the Supply Chain is becoming a choice of subject, when it comes to maintain the ideal inventory levels and Just in Time service deliveries. Both AI and ML are the utmost importance for the maintenance of the inventory or service through the technology. It not only helps in reducing the loss of opportunity costs, but also it resolves the issue of overstocks of any inventory and the enhanced level of service delivery. This ultimately results in the optimum utilization of the resources through the help of technology. Moreover, it is the win-win situation for the customer and provider. Even while technology has only recently begun to be incorporated into supply chains, the manufacturing and distribution sectors have adopted it more quickly, emphasising the need for effective risk identification and mitigation techniques. Notwithstanding the possible advantages of transforming the supply chain, there are obstacles and limitations that make an entire technological shift complex. The chapter also explores the concept explainable AI which can be understood as the set of techniques that makes the decision-making processes of AI systems comprehensible to humans. Acknowledging the inherent complexities and relationships within these chains, the goal of this chapter is to explore risk identification and management in high-tech supply networks. A competent and nimble stakeholder base can manage the complex landscape of the high-tech world through the incorporation of innovative technologies, proactive actions, and constructive alliances.

On plutonium-241 and americium in the two-component nuclear energy system

The paper deals with the influence of the strategy for using separated plutonium from spent fuel of thermal and fast reactors, as well as homogeneous burning of americium in the BN reactor core on the balance of americium in the Russian nuclear fuel cycle throughout the 21st century. The assessment is carried out with the use of mathematical modeling of nuclear materials movement including nuclide transformations throughout the nuclear energy system based on the CYCLE code. Scenario modeling of the americium and Pu-241 accumulation was carried out in Russia’s two-component nuclear energy system model with thermal (VVER) and fast (BN) reactors. In so doing, spent nuclear fuel (SNF) reprocessing was simulated in 2 options: as priority reprocessing of SNF of VVER reactors (1) or SNF of BN reactors (2). In addition to americium accumulation in the system without burning, the accumulation of this actinide was studied taking into account its homogeneous burning in the MOX-fuel of fast reactors at the level of its equilibrium content of ~1%. It has been shown that the priority reprocessing of VVER spent fuel makes it possible to reduce the americium accumulation by the end of the century by ~8 tons, and the effect is achieved by using freshly separated plutonium with short-term cooling, thus, by priority the americium source is eliminated, without directly handling it. Homogeneous addition of americium to the fuel of fast reactors of the BN-1200 type at a level of ~1% makes it possible to stop accumulation of americium in a two-component energy system by 2070, stabilizing it at a level of ~40 tons in the scenario with priority reprocessing of VVER SNF and ~50 tons in the scenario with priority reprocessing of BN SNF.

Circulations: Place, Movement, Belonging

This introduction to the special issue, ‘In(tangible) Circulations: Pathways of Sociality in Highland Asia,’ posits ‘circulations’ as a fundamental modus operandi of place-making and of forms of belonging that transcend geographical or physical boundaries. The notion of ‘circulations’ is conceived as the movement of material and intangible things and beings, the circuits of going forth and coming back, and their role in the continuous entanglements of people with their environment. These material and intangible movements generate what we call ‘pathways of sociality’ considered as sites for exchange that convey human relationships and values. Following these pathways compels us to look at circulations across worlds (human and non-human) and at different scales in their horizontal (societal) and vertical (spiritual) dimensions. The evolution of various circulations and the emergence of pathways contribute to the formation of relationships integral to people’s social landscape.

Blue Light Controlled Supramolecular Soft Robotics of Phenylazothiazole Amphiphiles for Rapid Macroscopic Actuations.

Nature preprograms sophisticated processes in operating molecular machines at the nanoscale, amplifying the molecular motion across multiple length-scales, and controlling movements in living organisms. Supramolecular soft robotics serve as a new alternative to hard robotics, are able to transform and amplify collective motions of the supramolecularly assembled molecular machines in attaining macroscopic motions, upon photoirradiation. By taking advantage of oriented supramolecular macroscopic soft scaffold, here the first rapid macroscopic movements of supramolecular robotic materials driven by visible light are presented. Head-tail amphiphilic structure is designed with the phenylazothiazole motif as the photoswitching core. Unidirectionally aligned nanostructures of the amphiphilic phenylazothiazoles are controlled by non-invasive blue light irradiation and bends toward the light source, demonstrating a fast macroscopic actuation of supramolecular robotic systems (up to 17°s-1) in aqueous media. Through meticulous X-ray diffraction and electron microscopy analyzes, macroscopic actuation mechanism is illustrated in a tight relation to molecular geometric transformations upon photoisomerization. By elucidating the key macroscopic actuation parameters, this paves the way for the next generation design of supramolecular soft robotic systems with enhanced biomimetic actuating functions.

Effects of triflute pin geometry on defect formation and material flow in FSW using CEL approach

Complicated tool pin designs in Friction Stir Welding (FSW) need to be considered in terms of material flow and defect formation. This study investigates the effects of the triflute tool's geometrical parameters on temperature, strain, void formation, and material mixing using a numerical method. The numerical model employs a coupled Eulerian-Lagrangian (CEL) formulation and successfully predicts void formation and material mixing during friction stir welding (FSW). Four tool pin designs are considered for material flow, including one cylindrical pin and three triflute pins with flute radii of 1 mm, 1.5 mm, and 2 mm. The findings indicate that the stir zone is divided into shoulder-driven and pin-driven zones, each exhibiting distinct material flow patterns. In the shoulder-driven zone, material flow toward the advancing side is dominant, while in the pin-driven zone, it flows toward the retreating side. Flutes on the FSW pin tool increase the sweeping rate, strain, and material movement in the stir zone. However, flutes with a larger radius sweep a greater amount of material and thus require more softened material to facilitate movement. Therefore, for defect-free joint formation, a higher rotational speed of the tool will be required, which may adversely affect tool lifespan and joint mechanical properties. The effectiveness of flutes with a smaller radius of 1 mm is significantly greater than that of those with a larger radius (1.5 or 2 mm) in enhancing material flow and achieving defect-free welding.

Execution of revised BMIM similarity coefficient for part family formation in reconfigurable manufacturing system

The reconfigurable manufacturing system (RMS) is an advanced manufacturing strategy that enables precise adjustment of functionality and capacity to meet fluctuating demands economically. RMS focuses on part families, allowing configurations to be adapted for new part requirements. Optimizing flow line design to produce various parts involves minimizing reconfigurations and associated costs by enhancing operation sequence similarity. This article proposes a novel sequence optimization using the Longest Common Subsequence (LCS) method to reduce bypassing moves and machine idle times. The study introduces a similarity coefficient derived from LCS and employs average linkage hierarchical clustering to categorize parts in a case study. Unlike traditional methods, this approach considers material movements both before the initial machine and after the final processing station, addressing gaps in bypassing move calculations. The impact of different weighting scenarios for Type-II moves (ω) and machine idleness (β) on clustering was examined. For example, with Type-II move weights (ω) of {1.0, 0.6, 0.3, 0.0} and equal weightings for bypassing moves (α) and machine idleness (β) set at 0.5, a threshold value of 0.3 results in eight clusters, such as Cluster 1 {1, 11, 10, 12} and Cluster 3 {3, 5, 6, 4, 15, 9, 13, 14, 7, 8}. Lower threshold values lead to fewer clusters with larger sizes, indicating a more consolidated part family grouping. Various Type-II move weights and material handling scenarios demonstrate how different weighting configurations affect clustering and part family sizes. This approach enhances RMS efficiency by integrating comprehensive material handling considerations and optimizing clustering based on operational similarities.

Spectral ruins: Empathy with inanimate material movements

Simulations are interactive, lively models of material events. Working with simulations that require the consideration of mass, gravity, and texture becomes an embodied experience. Much like video games, simulations imitate the physics of the material world and, as such, engage us corporeally. This dynamic between interactive model and user is particularly generative when the content of a simulation is inanimate, or inorganic materials. Digital models of static matter in motion offer the user a unique opportunity to relate to things that are typically understood as inert or nonliving. While empathy with the nonliving is a complex relationship to authentically construct, the ecological implications of this interaction are significant. This paper uses critical tools from video game studies and media theory to study simulations in experimental architecture and contemporary fine art practice. The essay posits a thesis informed by ecocriticism that users can build a tactile, bodily understanding of material behaviors by designing and interacting with tools built into animation, gaming, and visual coding platforms. A series of case-studies in art and design are examined with particular emphasis on their use of digital physics engines and code libraries that imitate natural behaviors.

Optimization of Warehouse Operations for Upstream Service Companies in the Oil & Gas Industry: A Case Study of XYZ Company

The oil and gas (O&G) sector drives various parts of Malaysia's economy and accounts for 19% of government revenue in 2021. The volatility of oil prices and the COVID-19 pandemic problem in recent years has taught O&G enterprises, especially upstream players, to focus on business needs and employ cost optimization techniques to compete and survive uncertain circumstances. This study seeks to analyze and describe the warehouse operations setup of an onshore supply base service organization that manages and maintains offshore O&G facilities. This study examines space utilization variables from several supply chain perspectives, particularly operations performance. Semi-structured interviews, site observations, and documentation review are used to collect data for the single-case study. The study findings suggest the organization under study has a basic warehouse setup with lean operations staff to complete business functions. In general, the warehouse arrangement for the organization under investigation is comparable to a distribution center, where 70% of warehouse activities comprise, material receiving, handling, and distribution (loading) to several offshore locations. Findings also showed that two factors, namely: material handling flow and movement, and inventory movement affect warehouse space utilization. The volume of material handled by the warehouse based on business demand, as well as the seasonal trend from offshore activities contribute to the frequency of material loading and impact the material throughput and transit time, which were found to have an impact on space utilization too.

Comparison of active and passive vibration control techniques for electric drive power electronic subsystem: Experimental validation

Reducing vibration and noise from power electronics components is vital for enhancing the performance and acceptance of electric vehicles, emphasizing the need for effective mitigation strategies in sustainable transportation. This paper compares passive and active vibration techniques, with a specific focus on utilizing particle damping for passive vibration control. The method achieves vibration reduction through viscoelastic deformation and friction resulting from the movement and collisions of granular material within the cavity. This contribution outlines diverse design strategies for integrating particle dampers into power electronic components. The active control approach, operating typically in the 50 Hz to 1200 Hz frequency range, can concurrently support passive noise treatments. Piezoelectric ceramics serve as both actuators and sensors in active noise reduction. Following the identification of dominant mode shapes, appropriate actuator and sensor positions are chosen. The control problem of the smart system is then addressed, opting for a velocity feedback control algorithm in a real collocated design. This algorithm computes input signals for actuators bonded to the outer surface, achieving significant active damping effects. Lab-tested techniques are validated in real-world conditions with a full-scale electric-drive toolkit, affirming their efficacy in reducing vibration and noise and underscoring their potential for implementation in electric vehicles.

Pengaruh Rantai Pasok Halal Terhadap Kinerja Produksi Makanan UMKM

The supply chain is a series of overall processes starting from the management, movement, storage and handling of raw materials, inventory of semi-finished goods, which ends with satisfied customers. Researchers use the R-A theory (Resource-Advantage Theory) to explain internal factors and the role of company performance. Researchers use quantitative research with survey methods with data collection techniques, namely questionnaires. The level of potential for the development of MSMEs in Jember Regency is large and continues to increase based on data from the Central Statistics Agency (BPS) Jember Regency also has the largest number of MSMEs in East Java with a total of 647,416. In addition, the market coverage it has is already extensive to various cities and provinces. This is supported by data obtained from media such as Jember radar, detik.com, Tv One, and Kompas Tv. Seeing from these data, its distribution and marketing in Mayang District are areas with the highest production compared to other areas. The population in this study were all Mayang Peanut Cake MSMEs as many as 31 Mayang Peanut Cake MSME business actors in Jember Regency. The results of this study used multiple linear regression analysis by conducting a t-test (partial) and f-test (simultaneous). The results of the analysis indicate that partially the three variables in this study, namely the halal supply chain, HR quality, marketing have a positive and significant influence on production performance. Simultaneously, the three independent variables in this study have a positive and significant influence on the performance of MSME food production.

Metallurgical characteristics and mechanical properties of dissimilar friction stir welded DH36 steel and UNS G10080 steel joints

The present study expanded the scientific comprehension of the friction stir welding process for dissimilar steels, namely high-strength shipbuilding grade DH36 steel and UNS G10080 steel. The effect of tool traverse speed and plunge depth on temperature history, microstructure characteristics, and mechanical properties is investigated experimentally. The metallographic characterizations were examined through an optical microscope and field emission scanning electron microscopy equipped with an energy-dispersive X-ray system. Microhardness, impact, and tensile tests were carried out on the friction-stir-welded specimens. Increasing the plunge depth and reducing the traversal speed resulted in an augmentation of the peak temperature, primarily attributable to higher heat generation. Within the range of process parameters used, the tool produced complex material movement, resulting in swirl-like and vortex-intercalated features, particularly adjacent to the stir zone/workpiece interface. These vortex-like features exhibited dynamically recrystallized fine-grained microstructures. The grain size in the stir zone and the thermo-mechanically affected zone is reduced by increasing the plunge depth and decreasing the traverse speed due to enhanced dynamic recrystallization, subsequently improving the hardness and toughness values. In the stir zone, the microstructure revealed the acicular-shaped bainite ferrite in the DH36 steel and the Widmanstatten ferrite in the UNS G10080 steel. The microhardness contours revealed the uneven hardness distribution across the weld cross-section due to the microstructural heterogeneity in the dissimilar steels. The maximum welding efficiency of 106 % and toughness of 46 J are obtained at 40 mm/min traverse speed with a plunge depth of 0.2 mm, which is attributed to sufficient heat generation and grain refinement.

Preliminary Removal of Mercury from Depleted Coal Sorbents by Thermal Vacuum Method with Associated Extraction of Precious Metal Composite

This paper presents the results of laboratory studies for the distillation of mercury from depleted coal sorbents produced in gold recovery factories using CIP technology. The mercury content in these materials is more than 1%. The developed technology was tested in a large-scale laboratory on a pilot vacuum sublimation electric furnace with the rheological movement of dispersed material. The use of this equipment makes it possible to demercurize various materials with fairly high moisture (up to 20%). It eliminates the use of an additional technological operation—drying the material in a vacuum drying oven. It has been shown that a high degree of mercury distillation is achieved (more than 99.8%) at 350–400 °C in the reaction space and residual pressure in the system of less than 1.33 kPa, with residual mercury content in the material of less than 0.001% (10 mg/kg), which complies with the European environmental standards. Mercury-free coal sorbents are sent for combustion for the additional extraction of precious metal composites. The proposed vacuum technology is characterized by its environmental safety because the process is performed in sealed equipment, eliminating toxic emissions of mercury vapor into the atmosphere. The proposed vacuum technology equipment is characterized by reliability and ease of use.

Crafting shape-changing experiences: emotional evaluation of morphing metamaterials

ABSTRACT We introduce a novel approach to evaluate how the design properties of morphing metamaterial influence shape-changing experiences. We leverage parametric design to create cutting patterns that change the Density and Geometry material properties. Using laser-cutting, we apply the patterns to a non-stretchable woven textile, resulting in a stretchable metamaterial that we actuate using an electromagnetic coil. This systematic design approach leads to programmatic control over the material movement, making it suitable for controlled evaluation of perceived experience. In a 2×2 mixed-method study, we assess how the metamaterial’s Density and Geometry properties impact the observed experience. Our findings indicate that such changes significantly and independently affect participants’ perceived emotions, mood, associations, and preferences. Our research contributes to the body of work of systematic studies in the shape-changing community. By using our morphing metamaterial design and implementation technique, coupled with our controlled evaluation of specific design properties, we have revealed new insights about the influencing factors of shape-changing experiences. We have incorporated these insights into our morphing metamaterial design guidelines, which outline the impact of Density and Geometry properties on an observer’s perceived emotions. We hope our work will open up new possibilities for expressive, evocative metamaterial-focused shape-changing experiences.

When detection and quantification of mineral fibres in natural raw materials are at their limit – the case of a clay from the Gomsiqe–Puka mining area (Albania)

Abstract. In today's global market, the movement of raw materials and goods in the free global market can lead to unintended consequences. One significant concern is the potential presence of contaminants and carcinogens, particularly when products originate from regions with less strict regulations and enforcement. This issue is particularly pertinent in the natural raw materials utilized in the global building materials market, where contamination by asbestos minerals can occur. Therefore, the screening of natural raw materials for asbestos content is crucial to mitigate the risk of exposure to carcinogens for both workers and the general public. In this study, we examine a challenging case involving a smectite–kaolinite clay from Gomsiqe–Puka, Albania, possibly containing mineral fibres. Detection and quantification of asbestos in this material push the boundaries of current experimental methods. Using transmission electron microscopy (TEM), micro-Raman spectroscopy, and electron probe microanalysis (EPMA), we identified the presence of asbestos tremolite, along with a rare fibrous variety of diopside. EPMA data allowed the advancement of some speculations on the origin of the observed tremolites, showing that Al-rich tremolites are typical of oceanic settings and Al-poor tremolites are more similar to continental tremolites. We also investigated the impact of milling on the detection and quantification of mineral fibres, testing different milling times. This investigation is crucial as it can influence the classification of the raw material as asbestos-containing material or not. Our findings indicate that tremolite, cleavage fragments, and elongated particles break down into smaller World Health Organization (WHO) fibres with increasing milling times (1–5 min). However, prolonged milling (10 min) leads to overgrinding, resulting in a decrease in the number of counted WHO fibres with a length exceeding 5 µm.

Performance and behaviour of prebored and precast pile with floating pile tip based on A full-scale field static axial load test

This study investigates the load transfer mechanism of a Prebored and Precast pile (PP pile), constructed installed in accordance with the rules applicable to the Hyper-Straight pile method (HS pile), in clay soils. While the HS pile method, developed in Japan, typically results in high bearing capacity piles in various soil types, its performance in clay soils remains understudied. Our research focuses on a unique configuration where the pile tip “floats” within a soil–cement mixing (SCM) column near the bottom of the borehole, a condition that significantly influences the system’s performance.We conducted a full-scale axial static load test on a 500 mm diameter and 140 mm thickness straight shaft precast prestressed concrete spun pile. The pile was instrumented with vibrating wire strain gauges (VWSG) and displacement measuring devices (tell-tales), embedded 15 m deep in a 750 mm diameter SCM column (15.75 m long). The pile tip was positioned 75 cm above the bottom of the borehole, creating a floating condition within the SCM material. Both the pile and the surrounding SCM were instrumented to provide comprehensive data on the system’s behavior.The test involved two loading–unloading cycles. The 1st Cycle reached a maximum load of 3627 kN, resulting in a 75.52 mm pile head settlement. The 2nd Cycle achieved a maximum load of 4181 kN, leading to a 118.04 mm pile head settlement. In the 1st Cycle, we observed upward movement of the SCM material around the shaft after the pile skin friction reached its maximum capacity. Stress at the pile tip exceeded the unconfined compressive strength of the SCM material, indicating potential local shear failure.Contrary to expectations based on HS pile performance in other soil types, the ultimate bearing capacity of our pile was determined to be 2000 kN, comprising 545 kN from skin friction and 1455 kN from end bearing. This result aligns more closely with the behavior of conventional bored pile rather than the “hyper” capacity typically associated with HS pile. Consequently, we classify our pile as a “prebored and precast pile,” like systems used in China and Korea.Our study concludes that the strength of the SCM material and the pile tip location significantly influence the pile’s bearing capacity in clay soils. These findings highlight the critical impact of soil type on the performance of piles constructed using the HS method. The observed behavior suggests that current design methods for HS pile may overestimate capacity in clay conditions, emphasizing the importance of soil-specific analysis and testing.This research contributes to the understanding of PP pile behavior in clay soils, providing valuable insights for geotechnical engineers. It underscores the need for refined prediction models and design methods specific to these soil conditions, paving the way for more accurate and reliable foundation designs in regions with predominant clay soils.