Material Waste Research Articles

Theoretical analysis of the forming process of closed die forging with flash and optimization design method of flash gutter

The subject of this article is the forming process of closed die forging with flashes and the optimal design of the flash gutter dimensions. The goal is to conduct an in-depth theoretical analysis of the forming process of closed die forging with flash and to research the optimal design of the flash gutter dimension, aiming to improve the scientificity and efficiency of the forging process, guide the optimization of process parameters in actual production, extend the service life of dies, reduce material waste, and enhance product quality and production efficiency. The tasks were to establish an accurate mathematical model for closed die forging with flash to analyze metal plastic deformation and stress distribution, to conduct in-depth research on key factors such as stress distribution, position of the neutral plane, and flash gutter design during the forming process, and to validate the mathematical model through finite element simulation using DEFORM-2D software. The methods used include theoretical analysis, mathematical modeling, and finite element simulation validation. The theoretical analysis provides a foundation for understanding the forming process and stress distribution, whereas the mathematical model allows for quantitative analysis. Validation of the finite element simulation provides a means to test and refine the theoretical analysis and mathematical model. The following results were obtained: the existing mathematical model underestimates the height of the main deformation zone, which results in an unreasonable flash gutter design. After verification and correction, the error in the optimized mathematical model did not exceed 10 %, and the flash amount was significantly reduced. Additionally, a stress analysis of difficult-to-fill cavity positions revealed that the entrance radius of the cavity significantly affects the final filling. Conclusions. The scientific novelty of the results obtained is as follows: A mathematical model of closed die forging with flash was established to analyze the metal plastic deformation and stress distribution, providing theoretical support for die design optimization, forging quality improvement, cost reduction, and productivity improvement. Using the Deform-2D finite element simulation, the optimal design criterion for the flash was refined, resulting in a substantial reduction in the flash amount and material savings.

A compartmentalized microfluidic platform to investigate immune cells cross-talk in rheumatoid arthritis

The dysregulation of the immune system plays a crucial role in the pathogenesis of manyfold diseases, among which we find rheumatoid arthritis (RA), an autoimmune disease characterized by chronic inflammation in synovial joints, leading to pain and disability. Immune cells such as pro-inflammatory macrophages and T helper 1 (Th1) cells drive the inflammatory cascade. Thus, including immune system inin vitromodels is pivotal to recapitulate and better understand the complex interactions between these immune cell subsets and their secreted mediators. Here, a compartmentalized microfluidic platform is presented, for precise confinement of circulating immune cells in organs-on-chip. The integration of innovative normally-closed sieving valves allows, through minimal waste of biological material, to co-culture different immune cell types (e.g. macrophages and Th1). Moreover, the platform allows to stimulate cell subsets separately, and to assess their cross-talk at desired time points. Functional validation of the platform demonstrates its ability to create stable chemotactic gradients, allowing for induction and evaluation of Th1 cells migration. In a proof-of-concept study, the platform allowed to assess Th1 T cells migration towards pro-inflammatory macrophages, thus replicating a characteristic interaction among immune cells triggered during RA onset. These results thus support the suitability of the platform to study immune cells cross-talk and migration phenomena, being potentially applicable to a manyfold immune cell mechanisms, both involved in RA progression and in different immune-mediated pathologies.

3D digital technology in upcycling apparel design: the creation of a modular redesign system and designer perspectives

ABSTRACT Despite advancements in sustainable apparel design, upcycling practices still face challenges limiting creativity and efficiency. This study develops a Modular Redesign System (MRS) using 3D digital technology to improve the upcycling process. The MRS was created with CLO3D and Aftereffects, producing ten redesign samples and demonstration videos. In-depth interviews with South Korean upcycling apparel designers were conducted to assess the system’s perceived effectiveness and explore key issues in upcycling design. The MRS involves four stages: Selection, Virtualisation, Virtual Ideation, and Construction and Fitting. Findings highlight the MRS’s ability to enhance ideation, reduce material waste, and save time and costs, offering practical solutions to current challenges in apparel redesign. The MRS also shows potential for mass customisation, serving as an effective communication tool for personalised upcycling services. This study bridges a gap in the literature by integrating 3D virtual simulation with modular design to advance sustainable and efficient upcycling practices.

Single-use technologies in bio manufacturing: benefits and implementation challenges

Single-use technologies (SUT) have revolutionized the bio manufacturing industry by offering flexibility, cost efficiency, and improved contamination control. Initially adopted for simpler processes, SUT has expanded to complex bioprocessing operations, driven by the growing demand for biologics, vaccines, and personalized medicines. This review explores the benefits of SUT, including reduced capital and operational expenditures, faster setup and turnaround times, and enhanced product safety. The scalability of SUT allows for rapid adaptation to market demands, significantly accelerating the time-to-market for critical therapies. However, the implementation of SUT is not without challenges. Material compatibility, leachables, waste management, and supply chain reliability pose significant hurdles. Moreover, regulatory and validation challenges complicate the adoption of these technologies in large-scale production. Case studies, including the rapid deployment of COVID-19 vaccines and the production of monoclonal antibodies, illustrate SUT's practical applications and benefits. The review also examines future trends, highlighting advances in materials, automation, and digital integration, as well as the expanding applications of SUT in cell and gene therapy manufacturing. As the bio manufacturing landscape continues to evolve, SUT will play a crucial role in meeting the industry's growing needs, provided the challenges associated with its implementation are effectively managed.

Life Cycle Assessment of Extraction of Cellulose from Date Palm Biomass Using Natural Deep Eutectic Solvent (NaDES) via Microwave-Assisted Process

This study investigates the extraction of cellulose from Saudi Arabia-based date palm biomass utilizing a natural deep eutectic solvent (NaDES) integrated with a microwave-assisted process. A comprehensive life cycle assessment (LCA) was conducted in accordance with the ISO 14040 standard, encompassing four key stages: goal and scope definition, life cycle inventory analysis (LCI), life cycle impact assessment (LCIA) and interpretation. The analysis was confined to a gate-to-gate boundary in which two impact assessment methods, namely, ReCiPe Midpoint (H) 2016 and ILCD 2011 Midpoint, were used to assess the environmental impacts. The OpenLCA software (version 2.1.1) with the European Life Cycle Database 3.2 (ELCD 3.2) was used in the study. The ReCiPe method identified impact categories such as fossil resource scarcity, terrestrial ecotoxicity, freshwater ecotoxicity, water consumption, human carcinogenic toxicity and marine ecotoxicity. Conversely, the ILCD method identified freshwater ecotoxicity, water resource depletion, mineral, fossil and resource depletion, human toxicity and cancer effects. The results indicate that freshwater ecotoxicity presents the most substantial environmental impact across both assessment methods, surpassing other categories. Fossil resource scarcity, even though originally appearing impactful, demonstrated a relatively lower normalized score compared to freshwater ecotoxicity. Terrestrial ecotoxicity and water consumption were found to be negligible in their impact. Our findings provide important insights into sustainable material science and waste management, affording potential applications for biomass utilization in the Gulf region.

Adoption of Lean Construction and AI/IoT Technologies in Iran’s Public Construction Sector: A Mixed-Methods Approach Using Fuzzy Logic

The construction sector in Iran faces substantial inefficiencies, including high material wastage, posing environmental and economic risks. This study investigated the adoption of Lean Construction (LC) practices and AI/IoT technologies in Iran’s public construction sector using a mixed-methods approach. This research examined the organizational, technical, and infrastructural factors across four key provinces—Tehran, Isfahan, Khorasan Razavi, and Fars—and employed fuzzy logic to address the uncertainties in adoption decisions. Data from 28 key stakeholder interviews were analyzed using Python 3.9, with libraries such as Pandas 1.3.3, NumPy 1.21.2, and skfuzzy 0.4.2 for the statistical analysis and NVivo 12 for the thematic coding. The analysis revealed that organizational readiness and leadership support were the critical drivers of adoption, particularly in Isfahan and Khorasan Razavi, which exhibited the highest adoption likelihood scores (0.5000). Tehran and Fars showed slightly lower scores due to regulatory barriers and financial limitations. The findings highlight the need for targeted leadership training, regulatory reforms, and infrastructure investments to accelerate the adoption of these technologies. This study aligned with the Sustainable Development Goals (SDG 9: Industry, Innovation, and Infrastructure and SDG 11: Sustainable Cities and Communities) by offering practical recommendations for advancing sustainable practices in Iran’s construction sector. The insights provided have broader implications for other developing economies facing similar challenges, contributing to global efforts toward sustainable development.

Pathways to a net zero building sector in Colombia: Insights from a circular economy perspective

The rapid urbanization and economic growth in Colombia have made the residential sector one of the largest energy and material consumers in the country. Circular economy (CE) strategies are a promising alternative to decouple the sector from resource depletion and climate change. The analysis shown here is based on the RECC model framework, a dynamic material flow analysis (dMFA) model. Our results suggest that by 2050 without CE strategies, residential building stock will reach 2.5 billion m2 and emit between 13 and 25 Mt CO2/yr, depending on whether carbon forest sequestration is included or not. A complete implementation of CE strategies and lower floor space can reduce 2020–2050 cumulative primary material production, waste generation, and GHG emissions by 48, 5, and 49 %, respectively. There is a potential to achieve net zero emissions by 2050 if, in addition to the measures mentioned above, more wood materials and forest sequestration are considered.

Sustainable Composites from Waste Polypropylene Added with Thermoset Composite Waste or Recovered Carbon Fibres

In order to limit the ever-increasing consumption of new resources for material formulations, regulations and legislation require us to move from a linear to a circular economy and to find efficient ways to recycle, reuse and recover materials. Taking into account the principles of material circularity and waste reuse, this research study aims to produce thermoplastic composites using two types of industrial waste from neighbouring companies, namely waste polypropylene (wPP) from household production and carbon-fibre-reinforced epoxy composite scrap from a pultrusion company. The industrial scrap of the carbon-fibre-reinforced epoxy composites was either machined/ground to powder (pCFRC) and used directly as a reinforcement agent or subjected to a chemical digestion process to recover the carbon fibres (rCFs). Both pCFRC and rCF, at different weight ratios, were melt-blended with wPP. Prior to melt blending, both pCFRC and rCF were analysed for morphology by scanning electron microscopy (SEM). The pCFRC powder contains epoxy resin fragments with spherical to ellipsoidal shape and carbon fibre fragments. The rCFs are clean from the matrix, but they are slightly thicker and corrugated after the matrix digestion. Further, the morphologies of wPP/pCFRC and wPP/rCF were also investigated by SEM, while the thermal behaviour, i.e., transitions and changes in crystallinity, and thermal resistance were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The strength of the interaction between the filler (i.e., pCFRC or rCF) and the wPP matrix and the processability of these composites were assessed by rheological studies. Finally, the mechanical properties of the systems were characterised by tensile tests, and as found, both pCFRC and rCF exert reinforcement effects, although better results were obtained using rCF. The wPP/pCFRC results are more heterogeneous than those of the wPP/rCF due to the presence of epoxy and carbon fibre fragments, and this heterogeneity could be considered responsible for the mechanical behaviour. Further, the presence of both pCFRC and rCF leads to a restriction of polymer chain mobility, which leads to an overall reduction in ductility. All the results obtained suggest that both pCFRC and rCF are good candidates as reinforcing fillers for wPP and that these complex systems could potentially be processed by injection or compression moulding.

Optimization of reduction gear in anchor winch based on modal analysis

In order to achieve more scientific design of the reduction gear and reduce material waste, pre-stressed modal analysis method was combined with multi-objective optimization algorithm to optimize the structure of the reduction gear basic body. The model was simplified and parameterized and the maximum stress and equivalent stiffness under different parameter size combinations were obtained through finite element analysis. Separately, genetic clustering method, neural network method, and Kriging method were used to construct the response surface function. Through error verification and comparison, it was found that the Kriging method was more suitable for the gear model. In the design of variable extremum search, multi-objective genetic algorithm and sequential quadratic programming were compared and analyzed. The results show that the mass of the gear can be reduced by 39.9 %, while the maximum stress remains unchanged, the equivalent stiffness is not reduced, and a good optimization design effect is achieved.

Optimizing Motorcycle Manufacturing Sustainability through the Integration of Waste Heat Recovery and Metal Scrap Recycling: A Process Engineering Approach

The automotive industry manufacturing has experienced rapid growth 2–3 times by 2050, with motorcycles constituting around 30% of vehicles worldwide, but this increase in production has significantly heightened the demand for raw materials and energy. A major challenge arises in managing material waste and waste heat generated during the manufacturing process. This research aims to develop a framework that optimizes the synergy between material waste recycling and waste heat recovery to enhance the sustainability of the motorcycle industry, reduce waste, and lower energy consumption. The design leverages waste heat from the melting process to preheat raw materials, raising temperatures from around 50 °C to 350 °C before melting, thereby reducing additional energy needs, lowering emissions, and decreasing operational costs. Utilizing waste heat for preheating not only mitigates environmental impact and thermal load but also significantly improves energy efficiency, ultimately resulting in cost savings and optimized resource use. Utilizing waste heat directly for preheating raw materials has effectively lowered energy consumption by as much as 30%. This approach not only improves operational efficiency but also decreases production costs and minimizes environmental impact, offering a more sustainable solution for the manufacturing sector.

Obtaining Highly Efficient Radon Adsorbents by Adjusting the Pore Structure of Bamboo Charcoal with Particle Size Fractionated Activation.

To achieve highly efficient adsorbents for radon (Rn), this study prepared bamboo activated carbon (BAC) using bamboo charcoal as the precursor and KOH and NaOH as activators and employed a method of activation by adjusting the pore structure through particle size fractionation. Under the same activation conditions, KOH was consumed less and showed better Rn adsorption performance than NaOH, and the solid milling method saved more activator dosage compared to the liquid immersion method. After carbonizing the bamboo, the highest Rn adsorption coefficients of the bamboo charcoal activated with particle size fractionation (0.43-0.85, 0.25-0.43, 0.18-0.25, and <0.18 mm) were 8.41 ± 0.05, 10.03 ± 0.24, 9.31 ± 0.01, and 8.15 ± 0.21 L/g, respectively under N2 conditions (at a temperature of 25 °C and humidity of 35%), which were significantly greater than those of bamboo charcoal with overall activation (7.05 ± 0.23 L/g). After optimization, all of the bamboo charcoals with different particle sizes had the highest volume ratio for pores with a diameter of 0.77 nm. BC0.43-0.85K1.25 and BC0.25-0.43K0.75 maintained 95.74 and 92.36%, respectively, of the original adsorption coefficient after 5 cycles of regeneration under nitrogen. As the bamboo charcoal particle size decreased, the optimal mass ratio of alkali/carbon also decreased. This indicates that particle-size-fractionated activation can reduce the raw material and activator waste. The optimized BAC has a significantly higher Rn adsorption coefficient than the currently used coconut shell activated carbon (4.13 ± 0.51 L/g), making it an efficient and economical adsorbent with excellent application value for radon removal.

Luminance-based methodology for assessment of low level haze in glazing

AbstractVisual defects, in particular haze, in glass and façade technologies can significantly impact the aesthetic quality and human experience of daylight and views in buildings. The glass and façade industry increasingly requires methods that can objectively predict and measure the subjective user experience of haze. This is required to appropriately inform the manufacturing process, ensuring optimal functionality and performance, and avoiding material waste and economic losses due to the replacement of defective glazing. Existing methods for measuring haze are not appropriate for assessing large samples, either at manufacturing sites or in-situ. However, haze defects are often only exhibited and visible when glazing is produced in large samples or installed under real luminous conditions. This paper introduces a novel luminance-based method that measures haze by evaluating the halo around a light source that is observed through the glazing. This method is initially tested in a controlled laboratory setting on small glazing samples with varying level of haze. The halo serves as a proxy for haze severity and it is quantified by using luminance-based measurements. In this work, the newly-proposed method is verified by comparing the ranking in haze severity of different samples as performed by means of a standard haze meter and the newly proposed method. Additionally, the paper examines the dependence of this ranking on factors such as camera setup distance and light intensity. It was found that the proposed method was able to effectively ranks samples differing in haze intensity by more than 0.1 orders of magnitude. Positioning the camera closer to the glazing and using higher light intensity yielded more accurate results. However, for haze levels below 1% and differences smaller than 0.1 orders of magnitude, the accuracy is insufficient. To define the expected level of accuracy of methods for haze characterisation in-situ, the sensitivity of the human eye to haze under varying luminous environments and view content needs to be quantified.

Carbon Sequestration by Preparing Recycled Cement, Recycled Aggregates, and Recycled Concrete from Construction and Demolition (C&amp;D) Wastes

As the world’s largest producer of construction waste, China’s recycling and related policies are of the biggest concern to the world. However, the effective disposal and reuse of this waste has become an important issue since currently China still has a very low recycling ratio compared to developed countries, and most of the waste concrete was only simply broken and used as low-grade recycled aggregates for subgrade cushion, cement stabilized crushed stone, and filler wall. In this paper, a concrete cycle model focusing on how to effectively recycle and utilize waste concrete is put forward to prepare high quality recycled concrete, especially through a series of technical means, such as effective separation, carbon sequestration, and reactivation. Producing high quality recycled concrete can not only replace traditional concrete but also effectively reduce the consumption and waste of raw materials. What’s more, the calculation results show a potential of significantly carbon sink; for every ton of recycled cement produced, the CO2 emission could be reduced by 0.35–0.77 tons compared to ordinary Portland cement, corresponding to a reduction of 47%–94%; and for every ton of recycled concrete produced, the CO2 emission could be reduced by 0.186 tons compared to normal concrete. A yearly CO2 sequestration of 1.4–3.08 gigatonnes could happen if the ordinary Portland cement could be replaced by the recycled cement around the world. Taking the currently accumulated construction and demolition (C&amp;D) wastes globally, the production of recycled cement, recycled aggregates, and recycled concrete could induce a significant carbon sink in the world.

Effect of toughening agent and flame‐retardant additives on the recycled polypropylene/oil palm empty fruit bunch laminated composites

AbstractThe increasing awareness of the environmental problems caused by the use of plastics has led to a demand for sustainable materials. The concept of turning waste into wealth has been considered in the study where the waste materials are value‐added into new composite materials that are recyclable, durable, and fire‐resistant. This effort aims to meet global environmental goals and the demand for high‐performance and sustainable building materials. The purpose of this current study is to develop laminated composites based on the combination of recycled plastic and oil palm empty fruit bunch (OPEFB). The addition of various loading of ammonium polyphosphate (APP) and 6 wt% of ethylene vinyl acetate (EVA) in the formulation was considered to enhance the performance of the composite laminates. The rPP and additives were compounded using a two‐roll mill. Then the rPP sheet and OPEFB were laminated using compression molding techniques. Results showed that rPP with addition of 30 wt% APP and 6 wt% EVA exhibited the highest thermal stability and the lowest melt flow index (MFI) value compared to other samples. Composites with 20 wt% APP and 6 wt% EVA showed 56% increase in flexural properties and 33% increase in impact strength compared to that of rPP/OPEFB composite sample without EVA. Addition of 30 wt% in recycled PP and OPEFB demonstrated self‐extinguished properties when exposed to fire compared to other samples. These findings indicated that rPP/OPEFB laminated composites with the addition of APP and EVA have a potential to be used in applications that require good strength and fire performance. The use of rPP/OPEFB composites with addition of APP and EVA has a potential to reduce virgin plastic consumption and agriculture material waste and establishing an environmentally friendly material for construction sector.Highlights Additives included in recycled PP enhance its thermal stability and reduce MFI. Recycled PP with OPEFB composite self‐extinguished at 30 wt% APP. The highest flexural strength is shown by composite laminates with 20 wt% APP and 6 wt% EVA. rPP/OPEFB laminates are ideal for building materials.

Understanding of additively manufactured material cyclic behavior at the grain scale by neutron diffraction and crystal plasticity modeling

Additive manufacturing (AM) offers distinct advantages in terms of complexity, reduced material waste, and shorter production times. However, the microstructures of AM alloys differ significantly from conventionally manufactured ones, and their impact on grain behavior remains uncertain. This study employs neutron diffraction, coupled with Crystal Plasticity Finite Element (CPFE) modeling, to investigate microstructural effects on cyclic behavior in 316L LPBF alloys. Neutron diffraction provides high-resolution strain and stress data at the polycrystalline level during loading, offering valuable insights into grain behavior. The CPFE model is initially validated at the grain scale using neutron diffraction, demonstrating its ability to predict local mechanical behavior in additively manufactured materials. This methodology holds promise for broader applications in various AM alloys, particularly when macroscopic identification of mechanical behavior is insufficient. Furthermore, the comparison between neutron diffraction and CPFE predictions allows to identify the influence of dendrites and dislocation substructures on the mechanical behavior at the grain scale. Notably, the micromechanical anisotropy resulting from dislocation organization along dendritic structures with specific orientations is highlighted. This study shows that despite the observed anisotropy, experimental measurement of intragranular strain distribution are correctly captured with a quantification of the deviation observed on some specific orientations due to the above cited microstructure sub-structures.

Mechanistic modeling of the dynamics of phage attack during milk acidification in the cheese-making process

Bacteriophage attacks represent a major threat in the dairy industry. Here, an unstructured mechanistic model predicting the dynamics of milk acidification in case of phage attack was developed and experimentally validated. Multiple acidification experiments were run with different combinations of initial phage titers and bacterial concentrations and the resulting pH dynamics were recorded. The model could successfully predict the success or failure of milk acidification. Using the model, important biological parameters were deduced from simple, low-cost acidification measurements. These parameters included bacteria’s maximum growth and lysis rates, phages’ burst size, etc. Sensitivity analysis helped identify biologically relevant aspects of phage-host interactions. Growth and lysis kinetics were shown to have the most important impacts. This knowledge can be used to develop easy routine strategies to fight phage attack in the dairy industry. The model can be used to raise awareness amongst cheese makers on the importance of cleaning to avoid food and material waste.

A socio-economic assessment of an emerging technology in the mining industry

Abstract Purpose This article provides methodological insights to evaluate the socio-economic risk of an emerging froth flotation technology for the mining sector with the goal of guiding the design and development process. This technology is used to separate valuable particles based on surface properties among minerals and, if properly developed, could be used to valorize fine particles that currently existing technology cannot separate and thus become waste material. Methods The Social Hotspot assessment utilized the Product Social Impact Life Cycle Assessment (PSILCA) database to analyze social hotspots in the relevant industrial sector. In addition, a survey captured the viewpoints of technology developers regarding additional potential social risk and opportunities. The final results were defined by combining these two analyses, conducted according to the 2020 UNEP guidelines for Social Life Cycle Assessment of Products and Organizations. For the economic assessment, the Material Flow Cost Accounting (MFCA) methodology (ISO14051) was applied, considering material costs, system costs, energy costs, and waste management costs for both the current situation and a future industrial-scale scenario. Results and discussion The study emphasizes the importance of tailoring methodological approaches for case studies involving low Technology Readiness Level (TRL) technologies based on available data. The state of technology development has led to different results for the economic and social analyses, primarily due to the difficulty in accurately predicting potential social impacts at this stage. The social analysis identified potential risks and 28 subcategories of impacts across different stakeholder categories. The economic assessment found that energy costs (49%) were the highest contributor to the MFCA cost of the future scenario, followed by system costs (29%). Conclusions and recommendations The study concludes that conducting a socio-economic analysis during the developmental stage of a technology is valuable for identifying critical hotspots that require monitoring, effectively guiding the research and development phase. This application represents a unique case in the mining sector and could be a first step in defining a methodological approach suitable for low TRL technologies. Analyzing both social and economic risks provides a more comprehensive perspective on sustainability, complementing environmental risk assessments.

Optimal Layout of Modular Systems by Geometric Perturbations

In this study, we investigate the potential of integrating geometric perturbations into the design process to optimise modular systems such as floor coverings, façade claddings, and masonry walls. By allowing small geometry adjustments of the initial design, we achieve significant reductions in material waste or labour requirements, leading to cost-saving and environmental benefits without compromising the design concept. We compared our approach to traditional methods, where the layout of the modular system is determined after the geometry of the design is finalised. To illustrate our method, we present case studies for two- and three-dimensional modular designs.

Novel Ceramic Clay Automatic Feeding System and Simulation Analysis

This study aims to verify the feasibility and effectiveness of an automatic feeding system in the ceramic clay-forming process. Through a series of clay-forming experiments, the system’s performance under various process parameters was examined. Precision sensors and data recording devices were used to monitor and record key data during the experimental process in real-time. The results demonstrate that the automatic feeding system can supply clay steadily and continuously under set parameters, ensuring a smooth forming process and significantly improving efficiency. Quantitatively, the system achieved a 30% increase in Vickers hardness, reflecting enhanced mechanical properties of the formed clay bodies. Additionally, there was a notable improvement in axial stress–strain characteristics, indicating better structural integrity and consistency. These improvements reduced human errors and material waste, enhancing production efficiency and product quality. Future research will focus on further optimizing system design and exploring its applications in a broader range of ceramic manufacturing processes.

Estimating construction and demolition waste in the building sector in China: Towards the end of the century

Amid China’s rapid urbanization and economic growth, increasing construction and demolition waste (CDW) has become a critical environmental and management challenge. In the present study, we introduce a dynamic recursive-based CDW assessment model designed to systematically track and analyze the origins, distribution, and composition of CDW across China. Our results show that China is projected to generate 224.08 billion tonnes (Bt) of CDW from 2000 to 2100, mostly gravel (34.15%), sand (30.08%), and brick/tile (14.37%). Additionally, the primary source of CDW generation will shift from rural to urban public and commercial (P&C) buildings. The proportion of metals such as steel in CDW is rapidly increasing, rising from 2.11% in 2000 to 17.66% in 2100. From 2020 to 2100, reducing material waste during the construction phase can decrease the amount of CDW by 6.88 Bt. Extending the building lifespan during the operation phase can further reduce the amount of CDW by 50.25 Bt. In comparison, implementing recycling strategies during the demolition phase can achieve the most significant reduction in the amount of CDW, with an estimated cumulative decrease of 151.25 Bt. The amounts of gravel, sand, and steel are anticipated to contribute the most to this reduction, accounting for 44.93%, 37.66%, and 8.8% of the total reduction in the amount of CDW, respectively.