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Melt-quenching bioglass-ceramics with the following chemical composition have been prepared 44SLS 11Na2CO3 24ES 6P2O5 6CaF2 9Al2O3 (wt%). The bioglass-ceramics were sintered at 650 °C, 750 °C, 850 °C, and 950 °C. The aim was to identify the optimal sintering temperature before glass crystallization. The physical properties were characterized by density and linear shrinkage. To characterize the structure properties, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were utilized. The high composition of Si and Ca in soda lime silica (SLS) glass and eggshells (ES), respectively, encourage the utilization of waste materials in the production of bioglass-ceramics. The results showed that at a sintering temperature of 950 °C, the crystallization of fluorapatite was the main phase. Moreover, the high density and optimum linear shrinkage were obtained as the sintering temperature increased. Additionally, grain growth and densification took place at this temperature. The compressive strength of bioglass-ceramics is influenced by sintering temperature and the optimal compressive strength is 136.58 MPa. [ABSTRACT FROM AUTHOR]

Anaerobic digestion has the potential to convert organic waste materials into valuable energy. At the same time, using press water from biomass materials for energy generation while taking advantage of the resulting cake for other purposes is an emerging approach. Therefore, this study aimed to investigate the residual potential expected from a typical biogas feedstock after it has been mechanically separated into liquid and solid phases. Hence, in this study, the rumen contents of ruminants (cow, goat, and sheep) and their proportionate ratios were obtained from an abattoir in Ghana. Resource characterization of the waste samples was carried out in the central laboratory of the HFR, Germany. Anaerobic batch tests for biogas (biomethane) yield determination were set up using the Hohenheim Biogas Yield Test (HBT). The inoculum used was obtained from an inoculum production unit at the Hohenheim University biogas laboratory. The trial involved two different forms of the sample: mixture of rumen contents, press water, and inoculum, each in four (4) replicates. The trial was carried out at a mesophilic temperature of 37 °C. Results obtained over a seventy (70) day period were transformed into biogas yields. Overall, the results show that the current contents are suitable for biogas generation as an option as opposed to the current form of disposal at a refuse dump. However, using these mixtures in their original forms is more technically viable than using press water without further treatment. [ABSTRACT FROM AUTHOR]

Developing effective, cost‐efficient, and eco‐friendly energy storage solutions is crucial for sustainable building structures. Red mud, a waste material, was used as the electrolyte and separator in supercapacitors, alongside activated carbon derived from jute sticks coated on steel mesh electrodes. Tests on RM‐enhanced supercapacitors showed that 20 % by weight of RM was the best amount. This increased the modulus of elasticity by 33 %, the tensile strength by 3 %, and the compressive strength by 10 %. Durability was largely unaffected, with minimal additional water absorption and slight shrinkage variation. The supercapacitor cell had an extended cell potential of 1.5 V and a maximum specific capacitance of 62.3 F g‐1 at 0.4 A g‐1, as shown by electrochemical tests. This improved energy density to 19.5 Wh kg‐1, with a power density of 301.8 W kg‐1 at 0.4 A g‐1 and a maximum power density of 605.8 W kg‐1 at 0.8 A g‐1. The cell retained 77 % of its initial capacitance after 450 continuous GCD cycles, demonstrating notable stability. This stability is due to the solid electrolyte and the synergy between JC and RM, indicating promising advancements for future energy storage devices. [ABSTRACT FROM AUTHOR]

One of the key trends affecting the future of the construction industry is the issue of ecology; therefore, current activities in construction aim to reduce the use of raw materials, which is made possible by including recycled materials in composites, among other methods. This article describes the results of tests conducted using four types of epoxy composites, i.e., composites modified with waste rubber (WR), composites modified with waste polyethylene (PE) agglomerate, glycolysate obtained using polyethylene terephthalate (PET) waste, and control unmodified mortars (CUM). Selected properties of the mortars were monitored during their maturation under laboratory conditions, as well as after post-curing at elevated temperatures in the range of 60 °C–180 °C. With the increase in the reheating temperature, an increase in the flexural strength of all types of mortars was noted, with the highest more than twofold stronger than the unmodified composites. The compressive strength increased up to a temperature of 140 °C, and then decreased slightly. The highest value of 139.8 MPa was obtained using PET mortars. Post-curing also led to a slight loss of mass of all samples in the range of 0 to 0.06%. Statistical methods were employed, which made it possible to determine the post-curing temperature and composite composition for which the determined properties are simultaneously the most beneficial, especially for the prefabricated elements. [ABSTRACT FROM AUTHOR]

This study provides a comprehensive evaluation of red mud as a sustainable material for road base construction, particularly in combination with bottom ash. Red mud, a by-product of the Bayer process used in alumina extraction, is known for its high alkalinity and heavy metal content. For this reason, this waste material causes environmental challenges. Red mud sourced from the Eti Aluminum Factory in Seydişehir, Konya (Turkey), was stabilized with bottom ash. Then, these waste materials were tested through a number of experiments, such as in relation to their Atterberg limits, compaction characteristics, unconfined compressive strength (UCS), California bearing ratio (CBR), and microstructure through a scanning electron microscopy (SEM) analysis. The results highlight that the UCS of stabilized red mud samples significantly improved with the addition of bottom ash and longer curing periods. Specifically, the UCS values increased from 0.5 MPa to 2.5 MPa after 28 days of curing. Moreover, RM specimens stabilized with 25% bottom ash achieved a CBR value of 146.64% after 28 days, far exceeding Turkey's road fill material requirement, which mandates a minimum unsoaked CBR value of 15%. These findings indicate that red mud stabilized with bottom ash not only meets but exceeds the structural requirements for road base materials. This approach provides a sustainable solution for the environmental management of red mud while contributing to infrastructure development. Through the recycling of these industrial by-products, this study presents a viable method to reduce waste and support economic and environmental sustainability in road construction projects. [ABSTRACT FROM AUTHOR]

Sustainability attracts high interest in various fields. Over 95% of roads are paved using Hot Mix Asphalt (HMA), consequently, employing one sustainable material adds significant value. In this work, modified dry methods are suggested to generate modified balls including Palm Leaf Fibers (PLFs). This study aims to evaluate the extent of improvement in HMA crack resistance using these balls. Measurements of volumetric characteristics, mixture sensitivity to moisture damage, and crack-related tests, namely, the Ideal-CT test, the Indirect Tensile Strength test (ITS), the fracture energy (Gf), the Cracking Resistance Index (CRI), the Flexibility Index (FI), and the Toughness Index (TI) were performed to assess the tensile strength of the mixtures. The results showed that the method deployed to create HMA using PLFs was effective in preventing cracks. Moreover, the results suggest that utilizing ITS test alone is insufficient in capturing all phases of mixture behavior since this test resistance to tensile cracking is largely dependent on the peak load whereas there are numerous characteristic indices, such as the CT-index, which provide a more accurate assessment. Therefore, this study offers a significant sustainable approach by modifying the mixing and improving the cracking resistance. [ABSTRACT FROM AUTHOR]

The present study investigates the optimization of the steam gasification process for the conversion of palm oil waste into environmentally friendly energy, utilizing the catalytic properties of calcium oxide and coal bottom ash. The objective of our research is to investigate the enhancement of the conversion process by employing a machine-learning approach. Specifically, we utilize a support vector machine (SVM) to model and evaluate the impact of different operational parameters on the resulting gas mixture. One notable feature of this study involves the incorporation of an adaptive marine predator algorithm (AMPA) into the SVM framework, aiming to enhance the predicted precision and efficiency of the model. The primary focus of this study revolves around the development of an intelligent optimization framework that surpasses conventional machine learning techniques, hence providing a more dynamic and efficient strategy for process improvement. The SVM model's performance, as assessed against experimental benchmarks, exhibits a notable degree of predictive accuracy and substantial concurrence with observed data. This increase in performance indicates that our methodology has the potential to make a significant contribution to the enhancement of renewable catalysts in gasification processes. The findings of this study could potentially have significant ramifications for the advancement of renewable energy production and the creation of intelligent systems in complicated industrial applications. [ABSTRACT FROM AUTHOR]

This study focuses on the integration of sustainable practices in construction projects by utilizing waste materials like waste plastic and rubber tires, specifically in Portland Cement Concrete (PCC) mixes. While adding plastic waste fibers (PF) has shown to enhance the performance of rigid pavements, the environmental and cost benefits are limited. On the other hand, using tire-derived aggregates (TDA) compromises the mechanical properties of PCC but offers significant environmental advantages and cost reductions. This study explores the outcomes of combining PF and TDA in PCC mixtures, assessing their impact on pavement performance through KENPAVE software, which evaluates deflections and cracking indices. Additionally, the environmental and cost effects of this combination are analyzed using the PaLATE 2.0 software, aiming to develop sustainable and economically viable rigid pavements.

There is a global concern with continuous waste production, and efforts are underway to use these wastes in the construction sector. The negative effects of excessive waste production and the use of virgin materials and energy in Hot Mix Asphalt (HMA) construction are challenging and require attention. The right step towards developing resilient road infrastructure is using cold bitumen emulsion mixtures (CBEMs), a cold mix asphalt (CMA). A long-term fix to issues with waste generation and the creation of flexible pavements with HMA can be found by incorporating wastes into CMA. This work reviews the utilization of numerous wastes from different sectors (agricultural, industrial, construction and demolition, and municipal) that are well-known but underutilized and could be used as potential fillers in cold asphalt mixtures. Focus is given to the critical analysis of wastes' physiochemical characteristics and how these affected the effectiveness of mixtures against primary distresses like stability, stiffness, rutting, cracking, fatigue, and moisture susceptibility. Almost all waste materials incorporation reported enhancement in the mechanical performance of CBEM mixes concerning conventional CBEM mixes. The paper sums up the impact on various mechanical properties of CBEM mixes utilizing waste material filler, presents research gaps and a way forward to inspire researchers, and serves as a guideline for using waste materials as fillers in CBEM mixes. This will improve environmental quality and promote sustainability in the paving industry. [ABSTRACT FROM AUTHOR]

Supporting sustainable development, contributing to reducing waste that causes environmental damage, and reducing the use of natural materials are part of preserving the environment and society. This is done by highlighting the manufacture of sustainable concrete pavement of acceptable quality and according to specifications. The authors previously produced a concrete pavement mixture with optimal properties by partially replacing the Portland cement with 55 wt.% of the ground granulated blast furnace slag (GGBFS) in addition to partially replacing the virgin aggregates with 30 wt.% of recycled aggregate from crushed rigid pavement. The goal of this research work is to produce a self-sensing rigid pavement mixture from wastes with high mechanical properties, that is better than regular concrete and less expensive. The new novel mixture has the ability to detect earlier the damages that occur to the concrete pavement so as to obtain a longer life by periodically maintaining the pavement on time. The previous mixture was improved by adding chopped steel shaving fibers with lengths ranging from 20-60 mm in four different volumetric ratios. These are 0.7%, 1%, 1.1%, and 1.2%. The results were compared with those of the basic mixture, and a decrease in workability and slump values were noticed. Moreover, significant improvements in the mechanical properties were obtained. The concrete's resistance to the applied loads increased by increasing the percentage of steel shaving in the mixtures, due to the increasing of cohesion forces within the mixture. The self-sensing capability for the developed mixtures was tested by measuring the changes in the electrical resistance under different types of mechanical loadings. The results showed that the direction of the applied load and the proportion of steel shavings affect the self-sensing properties in terms of the fractional variation in the electrical resistance (FVER, %), which highlights the importance of using steel shavings in producing smart concrete pavements from reused resources more efficiently and highly cost-effectiveness. [ABSTRACT FROM AUTHOR]

This paper presents an extensive comparative analysis of the experimental results of chemical stabilisation of clayey soil in laboratory conditions by comparing the effects of adding conventional stabilisers (lime, cement binder), stabilisers that can be considered as waste material (fly ash, rock flour), as well as alternative chloride-based materials (ferric chloride, calcium chloride, potassium chloride) on the geomechanical properties of the soil. With the aim of determining the stabiliser optimal content in the mixture with the soil, in the first part of the research, the effects of stabilisation of clayey soil of medium plasticity using the considered stabilisers with different percentage share on the change in uniaxial compressive strength (UCS) and pH value of the soil at different time intervals after the treatment were analysed. In the second part of the research, additional tests were conducted on soil samples with optimal content for each of the considered stabilisers by monitoring changes in the physical and mechanical properties of the soil. These include Atterberg's limits (liquid limit and plasticity limit), modulus of compressibility in the oedometer, California bearing ratio (CBR), and swelling potential at different time intervals after the chemical treatment to determine the durability of stabilisation effects. The results of the conducted research reveal that each of the conventional, waste, and alternative materials considered as chemical stabilisers contributes to the improvement of the geomechanical properties of the clayey soil, primarily in terms of increasing the bearing capacity and reducing the swelling of the treated soil. [ABSTRACT FROM AUTHOR]

In this paper, we aim to demonstrate that sustainability will be a must-have in the coming years. We will explore methods of reusing textile waste and reducing it. Sustainability starts with a global shift in perception, where designers need to change how they view clothes and their functionality. Beyond beauty, we are talking about finite resources, massive consumption, and a significant amount of waste. When we reuse, worn materials can be transformed into new products, reducing the need to consume natural resources for their production. By reusing waste from production or extracting pieces from other used items, we can preserve materials that hold sentimental value for us and utilize waste that would otherwise increase production costs through energy consumption. It is essential to change our habits related to how we "consume" clothes and to start thinking about the impact we have on the environment. It is important to realize that we can have a significant impact on the environment through the choices we make about the clothes we buy and how we manage them after we stop using them. It is our responsibility to change the way we consume and to act to protect the environment for future generations. This paper provides practical information on the process of textile waste recovery. [ABSTRACT FROM AUTHOR]

Mango is a popular tropical fruit known worldwide and mango peel is a waste product worthy of valorization. This study explores the stabilizing effect of hydrocolloids extracted from mango peel in dressing-type emulsions (DE). Emulsions stabilized with different ratios of mango (Mangifera indica) peel-derived hydrocolloids (PE) and guar gum (1 % wt. total concentration) were prepared and characterized: DE1 (0.25/075), DE2 (0.5/0.5), DE3 (0.75/0.25) and DE4 (1/0). Particle size distribution, ζ-potential, proximal composition, color, microstructure, and rheological properties were evaluated. All the samples showed similar proximal compositions. However, PE/guar gum ratio influences color parameters. For the microstructural analysis, Sauter's mean droplet size ranged from 6.41 to 11.11 µm. The ζ- potential values ranged from −18.03±0.21 to −16.97 mV. Emulsions exhibited shear thinning responses that can be well described by the Williamson model, and gel-like viscoelastic character with G’ higher than G”. The activation energy values (Eα) deduced from the application of an Arrhenius model to the viscous flow behaviour of the emulsions ranged from 108.46 to 143.44 Kj/mol. From the microstructural analysis and the rheological characterization, it can be inferred that PE favors the flocculation of the emulsion droplet in high concentrations. Overall, this research contributes to the sustainable exploitation of a mango waste material, such as the peel, in food emulsions.

The presented work was focused on developing a lightweight, quasi self-compacting, fiber reinforced concrete mix for pre-cast use. The research activities covered a complex iteration design process and experimental tests leading to the selection of the final mix. The threshold requirements for the final mix were: strength class of at least LC 25/28, quasi self-compacting properties of the fresh concrete mix and good quality of the surfaces of hardened elements. During the design process a wide array of lightweight aggregates was considered characterized by bulk density ranging from 340 kg/m3 to 750 kg/m3. Ten different concrete mixes were created. Two mixes characterized by most promising properties were further developed by the addition of steel fiber. Eventually, one of the mixes was chosen for the final tests. Compressive strength after different time intervals, tensile strength, shear strength and LOP characteristics of the chosen mix were of key interest. Durability associated properties were also tested. Ultimately, lightweight concrete with the density of 1640 kg/m3 and the strength class of LC 30/33 was obtained.

The use of pozzolanic materials as a sustainable partial replacement option for portland cement in concrete has been extensively studied over the last few decades. This study aimed to assess the pozzolanic reactivity of seven different powdered materials: pottery cull, brick powder, lightweight aggregate fines, class C fly ash, silica fume, glass powder, and dolostone. Pozzolanic reactivity was evaluated using seven different direct and indirect methods, including the Frattini test, strength activity index (SAI), ultrasound pulse velocity index (UPVI), thermogravimetric and differential thermal analyses (TG/DTA), calorimetry, electrical conductivity, and pH. Robust correlations and a ranking analysis were performed to evaluate the relationship and efficiency between various direct and indirect test methods. Results of the robust regression analyses showed that Frattini and TGA, SAI and electrical conductivity, SAI and calorimetry, and UPVI and calorimetry were well correlated, suggesting that these methods may be suitable alternatives to each other. According to the ranking method, electrical conductivity and calorimetry are the most rapid and efficient methods for the assessment of different pozzolans in comparison to other longer-duration test methods examined in this study.

AbstractWaste is considered a significant environmental issue in modern times thus the purpose of this paper is to compare the use of different waste materials in replacing aggregates in concrete. This study investigates the potential of incorporating plastic waste (PW), textile sludge (TS), and construction and demolition waste (CDW) into concrete as sustainable alternatives to traditional construction materials, by evaluating its mechanical, durability characteristics as well as the cost related to different process of the project. The study focuses on the use of PW and TS as a replacement for fine aggregate, and CDW as replacements for coarse aggregate. Thus, four concrete mixes incorporating PW and TS were prepared, using 0% 10%, 25%, 40% replacement levels. The compressive strength of concrete with 10% plastic waste as fine aggregate was 32.49 N/mm2 showing higher results than that of TS. Furthermore, another four concrete mixes incorporating CDW were prepared, using 0%, 25%, 50%, 75% replacement levels. The compressive strength of concrete with 25% CDW was 30.90 N/mm2 indicating an increase of 2% than the control block. The study concluded that the best strategy is to incorporate construction and demolition waste as a replacement for coarse aggregate in concrete. This is because it resulted in an increase in compressive strength as well as a decrease in cost. Public Interest StatementThis article is discussing the validation of the usage of various waste materials in place of aggregates in concrete, as waste is now considered as a major environmental issue. This study examines the viability of using construction and demolition waste (CDW), textile sludge (TS), and plastic waste (PW) in concrete as sustainable substitutes for conventional building materials, which will be a milestone in reaching the concept of sustainable housing. This will be reached by assessing the material's durability and mechanical properties as well as the associated costs of various project processes. The study focuses on replacing the coarse aggregate which is the dolomite with construction and demolition and replacing fine aggregate which is the sand in this case, with Plastic waste and Textile Sludge.

Abstract The present study investigates the optimization of the steam gasification process for the conversion of palm oil waste into environmentally friendly energy, utilizing the catalytic properties of calcium oxide and coal bottom ash. The objective of our research is to investigate the enhancement of the conversion process by employing a machine-learning approach. Specifically, we utilize a support vector machine (SVM) to model and evaluate the impact of different operational parameters on the resulting gas mixture. One notable feature of this study involves the incorporation of an adaptive marine predator algorithm (AMPA) into the SVM framework, aiming to enhance the predicted precision and efficiency of the model. The primary focus of this study revolves around the development of an intelligent optimization framework that surpasses conventional machine learning techniques, hence providing a more dynamic and efficient strategy for process improvement. The SVM model’s performance, as assessed against experimental benchmarks, exhibits a notable degree of predictive accuracy and substantial concurrence with observed data. This increase in performance indicates that our methodology has the potential to make a significant contribution to the enhancement of renewable catalysts in gasification processes. The findings of this study could potentially have significant ramifications for the advancement of renewable energy production and the creation of intelligent systems in complicated industrial applications.

Green energy harvesting devices are potential sustainable power sources for self-powered sensors, electronics, and the Internet of Things. Triboelectric nanogenerators (TENGs) based on natural polymers and waste materials can harvest green energy from vibration sources to convert it into electrical energy. These nanogenerators could substitute conventional electrochemical batteries to power future smart sensors and electronic devices without contaminating our ambient. Herein, we present a novel portable triboelectric nanogenerator formed by a waste corn husk and a recycled polystyrene (PS) plate as triboelectric layers. This nanogenerator has a compact and lightweight structure developed by a low-cost and eco-friendly fabrication process. This nanogenerator can convert vibrational kinetic energy into electrical energy, achieving a power density of 670.5 mW∙m−2 with a 51.9 MΩ load resistance and operating at 14 Hz. This portable nanogenerator includes simple signal processing and it can power an array of 472 commercial blue LEDs, a digital calculator, and a stopwatch. The output voltage of this nanogenerator is stable even after 25,211 operating cycles at 14 Hz with 25 mm of separation distance between triboelectric layers. The proposed nanogenerator has potential applications to power small electronic devices and sensors using vibrational kinetic energy from the environment.

The aim of this research is to investigate whether construction rubbles may be utilized as coarse aggregates in concrete. Experimentally, the slump, unit weight, compressive, tensile, and flexural strength tests were applied on concrete samples with varying percentages of recycled coarse aggregate (RCA) and compared with reference concrete produced with natural coarse aggregate. This research conducted 96 concrete samples with RCA replacement percentages of 0, 35, 65, and 100%, respectively. The control mixture produced with natural aggregate showed better results than the mixtures containing recycled aggregate; thus, compressive, tensile, and flexural strengths reduced as the amount of the recycled aggregate increased. Using 100% RCA, the compressive, tensile, and flexural strength reduction reached up to 64, 29, and 38%, respectively.

One of the most significant environmental issues worldwide is garbage, particularly waste from construction materials, which is generated in substantial numbers. However, in the building industry, the significant extraction of natural resources such as cement, natural sand, and natural gravel poses a critical environmental challenge, depleting these resources at an alarming rate. There are some solutions that developed countries are resorting to, namely the division of construction waste into groups, where it is reused under the name of recycling construction waste to produce new, environmentally friendly building materials. The aim of this research includes a laboratory process study as it includes the use of the following ratios: 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%, under the process of replacing coarse plain aggregates including coarse recycled aggregates and studying the most important mechanical properties of concrete. This research was carried out using fresh concrete properties such as workability tests and hardened concrete properties such as compressive strength, splitting, and flexural tensile strength examined at the durations of 7, 14, and 28 days. The research includes the investigation of the three main properties of concrete. After conducting the tests, the results have shown that the main property of recycled concrete is lower strength than that of conventional concrete, but it can be said that it is within the limits that can be used for construction. The results also showed that compared to normal aggregates, development in the recycled aggregate percentage rates reduces the operational workability of concrete. The research proved that the maximum decrease in compressive, flexural, and tensile strength, density and the slump were 19.4, 18.3, 19.6, 19.5, and 25.0% respectively compared to the control concrete samples. [ABSTRACT FROM AUTHOR]

This paper overviews the use of several waste materials for the construction and reconstruction of surface courses of asphalt pavements in the framework of sustainable perspectives that are adopted in pavement engineering. Based on a relevant literature search, the most commonly investigated alternative materials include waste plastic, crumb rubber, waste glass, steel slag, and Reclaimed Asphalt Pavement (RAP). Although recycling in pavement engineering is not a novelty, the strict performance requirements of the surface layers required to support a distress-resistant behavior possess continuous research challenges about the mechanical behavioral parameters, such as fatigue, rutting, moisture damage, and serviceability requirements, such as skid resistance. While studies in a laboratory environment mainly dominate, the importance of performance observations of real structures in the field is also pinpointed in an effort to provide a comprehensive overview of the so far knowledge status. Thereafter, this paper discusses peculiar issues and criteria for waste material selection that should balance performance requirements, local availabilities, and potential legislation concerns, thereby maximizing the economic or environmental advantages. [ABSTRACT FROM AUTHOR]

Using existing resources more efficiently and effectively becomes important currently. The question of how to make the best use of resources arises in the choice between constructing new roads and improving deteriorated existing roads. It is also important to reduce the amount of consumption and cost of materials. This has emerged the need to use waste materials by recycling and reusing. In this study, a new hot-mix asphalt (HMA) mixture was developed using recycled asphalt pavement (RAP), which was obtained by excavating the surface of a road at the end of its service life, together with a waste material namely natural pozzolan (NP). The final obtained mixture was used as a wear layer on an active highway. Core specimens were extracted from the paved layer for one year and subjected to dynamic and mechanical laboratory tests. Adding NP improved the resistance of the HMA mixture under heavy seasonal effects and traffic loads. In addition, NP increased the tensile strength, making the HMA mixture more resistant to deformation than control and RAP HMA mixtures. Dynamic creep test results showed that the control asphalt mixture had the most deformation and that the RAP mixture with NP had the least. According to the laboratory results, NP addition increased the stability value of the control mixture by 40%. Especially in cold seasons, the role of NP was more evident. In the performance tests that were applied on core samples taken from the field, ITS values for September increased by 98%, and the deformation values obtained as a result of the dynamic creep test decreased by 12%. In summary, adding NP to RAP HMA improves the performance of the pavement and the cost-effectiveness of the environmentally friendly use of RAP in HMA. [ABSTRACT FROM AUTHOR]

Geopolymers are binder materials that are produced by a chemical reaction between silica or aluminum compounds with an alkaline activating solution. Foamed geopolymer materials are increasingly being cited as a viable alternative to popular organic insulation materials. Since the foaming process of geopolymers is difficult to control, and any achievements in improving the performance of such materials are extremely beneficial, this paper presents the effect of the addition of basalt powder on the properties of foamed geopolymers. This paper presents the results of physicochemical studies of fly ash and basalt, as well as mechanical properties, thermal properties, and structure analysis of the finished foams. The scope of the tests included density tests, compressive strength tests, tests of the thermal conductivity coefficient using a plating apparatus, as well as microstructure tests through observations using light and scanning microscopy. Ground basalt was introduced in amounts ranging from 0 to 20% by mass. It was observed that the addition of basalt powder contributes to a reduction in and spheroidization of pores, which directly affect the density and pore morphology of the materials tested. The highest density of 357.3 kg/m3 was characterized by samples with a 5 wt.% basalt powder addition. Their density was 14% higher than the reference sample without basalt powder addition. Samples with 20 wt.% basalt addition had the lowest density, and the density averaged 307.4 kg/m3. Additionally, for the sample containing 5 wt.% basalt powder, the compressive strength exceeded 1.4 MPa, and the thermal conductivity coefficient was 0.1108 W/m × K. The effect of basalt powder in geopolymer foams can vary depending on many factors, such as its chemical composition, grain size, content, and physical properties. The addition of basalt above 10% causes a decrease in the significant properties of the geopolymer. [ABSTRACT FROM AUTHOR]

This work reviews Machine Learning applications in the sustainable utilization of waste materials as energy source so that analysis of the past works exposed the lack of reviewing study. To solve it, the origin of waste biomass raw materials is explained, and the application of Machine Learning in this section is scrutinized. After analysis of numerous papers, it is concluded that Machine Learning and Deep Learning are widely utilized in waste biomass production areas to enhance the quality and quantity of production, improve the predictions, diminish the losses, as well as increase storage and transformation conditions. The positive effects and application with the utilized algorithms and other effective information are collected in this work for the first time. According to the statistical analysis, in 20% out of the studies conducted about the application of Machine Learning and Deep Learning in waste biomass raw materials, Artificial Neural Network (ANN) algorithm has been applied. Afterward, the Super Vector Machine (SVM) and Random Forest (RF) are the second and third most-utilized algorithms applied in 15% and 14% of studies. Meanwhile, 27% of studies focused on the applications of Machine Learning and Deep Learning in the Forest wastes. [ABSTRACT FROM AUTHOR]

To solve the problems of difficult treatment and environmental pollution of regolith granite sand washing sludge (RGSWS 1 1 Regolith granite sand washing sludge.), the study was carried out to prepare ultra-lightweight ceramsite using RGSWS as the main raw material, silica fume as a conditioning agent, red mud as cosolvent, and phosphorus tailings as a pore-foaming agent. The effects of raw meal ratio, sintering temperature (1130–1280 °C), and sintering time (5–25 min) on the properties of ceramsite were investigated. Under the optimal preparation conditions (RGSWS: red mud: silica fume: phosphorus tailings = 60:20:20:10 and sintering at 1220 °C for 15 min). The ceramsite showed a high compressive strength of 2.63 MPa, an expansion rate of 133.7 %, a 1-h water absorption rate of 1.32 %, an apparent density of 792.3 kg/m3, and a bulk density of 349.2 kg/m3. The sintering process transforms the raw meal into substances such as mullite, diopside, and anorthite, which helps to improve the strength of the lightweight ceramsite. At the same time, harmful substances in the raw materials can be effectively solidified in the internal structure of the ceramsite, making the ceramsite have excellent environmental safety. Moreover, the full characterizations have been made to reveal the structure and formation mechanism of ceramsite. This research utilizes four kinds of solid waste to prepare valuable material, which is helpful for the development of environmentally friendly and ultra-lightweight construction materials. [ABSTRACT FROM AUTHOR]

This research addresses the importance of hybrid composites in material science, specifically, demonstrating the effective reinforcement of unsaturated polyester with bamboo and coconut husk fibre through alkali treatment. The primary problem this work aims to solve is the improvement of the mechanical properties of unsaturated polyester by combining it with bamboo and coconut husk fibres which contain both lignocellulosic and cellulose fibres. Alkali treatment, particularly, sodium hydroxide (NaOH) solution, was used in this study due to its cost-effective nature and its ability to enhance the strength of both individual fibres and resulting composite. The effect of NaOH treatment with concentrations ranging from 2 - 10 wt.% on dried hybrid fibres was investigated. Chemically treated fibre composites were discovered to have improved mechanical characteristics as both tensile tests and thermogravimetric analysis (TGA) showed higher strength and thermal stability after being treated. Notably, findings identified an optimal content of 8 wt.% NaOH solution for surface modification, showcasing the potential for using NaOH-treated waste fibres to reinforce polyester resin. The implications of this study extend to a promising avenue for enhancing the performance and application of natural fibre-reinforced composites. The insights provided here offer a foundation for advancing the utilization of hybrid composites. [ABSTRACT FROM AUTHOR]

The utilization of reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) in road infrastructure construction projects contributes significantly to the sustainable reduction of solid wastes being landfilled. This research aims to evaluate the mechanistic performance of asphalt concrete with RAP and RCA modified with natural hemp fiber (HF) reinforcement (HF-RAP-RCA-AC). The effect of influence factors, such as RAP/RCA ratio, HF length, and HF content, on the static and dynamic-mechanistic performance was evaluated. The static performance of HF-RAP-RCA-AC was assessed through the Marshall stability (MS), strength index (SI), and indirect tensile strength (ITS), while the dynamic performance was evaluated through the indirect tensile resilient modulus (IT Mr), indirect tensile fatigue life (ITFL), and rutting resistance tests. The HF-RAP-RCA-AC sample was found to have comparable static properties (MS and SI) to conventional asphalt concrete. The dynamic-mechanistic performance of HF-RAP-RCA-AC was however found to be significantly lower and hence HF-RAP-RCA-AC was found to be suitable for low-traffic roads. The improved ITS due to the addition of RCA and HF was found to influence the IT Mr improvement in the linear relationship. The improved resilient properties contribute to the ITFL and rutting resistance improvement. The optimum mix was found to be at 0.05%HF content, for all HF lengths and RAP/RCA ratios. The potential of HF reinforcement on the material properties was positively impacted by increasing the RCA content. The proposed distress model based on the critical analysis of the cyclic test data of HF-RAP-RCA-AC was developed and was found to have the same logarithm relationship. The outcome of this research will encourage the application of HF-RAP-RCA-AC as a sustainable pavement material for low-volume roads. [ABSTRACT FROM AUTHOR]

The goal of this study was to produce sustainable concrete by reducing reliance on cement, which contributes to high carbon footprints, and natural sand, which is being depleted. Sugarcane bagasse ash (SCBA) was used to partially replace cement at 5 %, 10 %, and 15 %, while recycled polyethylene terephthalate (RPET) was used to partially replace sand at 5 %, 10 %, 15 %, and 20 %. The effects of these substitutions on concrete's mechanical and physical properties were examined after 28 days of water curing. The study observed a decrease in fresh density by 0.36 %–2.67 % with SCBA and RPET inclusion. The slump values ranged between 93 mm and 140 mm, indicating good workability. The reference concrete's compressive strength was 39.65 MPa, while the mix with 5 % SCBA and 10 % RPET achieved 38.23 MPa. This mix also showed a 1.2 % higher split tensile strength than the reference concrete. Although the reference concrete's flexural strength was the highest at 4.56 MPa, all SCBA-RPET mixes remained within 86 % of this value. All modified mixes weighed less than the reference concrete, with the compressive strength-to-weight ratio of the mix with 5 % SCBA and 10 % RPET being closest to the reference mix with only a 2.44 % reduction. These findings suggest that SCBA and RPET can be effectively used to produce sustainable concrete with comparable mechanical properties to conventional concrete.

The partial replacement of conventional natural coarse aggregate (NCA) with artificial light weight aggregate (LWA) manufactured from local clay and solid waste to develop a lightweight aggregate concrete (LWAC) for the structural use was studied in this paper. Red clay and Savar clay were used individually with solid wastes like rice husk ash (RHA) and waste glass to produce LWA. The suitability of raw materials and LWA was evaluated by investigating various properties. The mechanical, thermal and durability properties of manufactured LWAC were explored. The results of physical, chemical, thermal and geotechnical properties revealed that Red clay is better than Savar clay for the preparation of LWA. All the physical and mechanical properties of LWA prepared from Red clay are suitable for the preparation of LWAC compared to Savar clay. The test results demonstrated that the concrete manufactured by replacing 30 % of NCA with LWA produced a concrete of lightweight properties. The compressive strength of LWAC for 7 and 28 days was observed as 28 and 48 MPa, respectively. The results of modulus of elasticity, splitting tensile strength, flexural deformation, and creep test of LWAC revealed that these mechanical properties meet the requirements for the structural concrete. The RCP test proves that chlorine permeability of LWAC is comparable with NCA. It was observed that the superior performance of LWAC can be achieved only when the optimized mix designed is followed strictly. The suitability of the replacement of natural aggregate by LWA may be helpful for Bangladesh due to the scarcity of natural coarse aggregate and reusability of solid waste materials.

Copper tailings are a category of solid waste discharged after the beneficiation process in mining plants. The significant concern raising stringent environmental issues give impetus to explore the multi-channel utilization of copper tailings in a sustainable manner. Concerning the fact that no study has systematically compared properties of copper tailings filled (CTP) asphalt mastic with conventional limestone filler mastic (LP) at different filler-to-asphalt ratios, multiscale and multi-dimensional comparisons between the characteristics of CTP-asphalt and LP-asphalt mastics were made in this study to thoroughly explore the feasibility and potential of recycling CTP as alternative filler in asphalt materials. Four ratios from 0.3 to 1.2 were used to manufacture asphalt mastics. The in-service pavement performance of asphalt mastics including resistances to rutting, low-temperature cracking and moisture damage was explored. Finally, the environmental and economic perspectives regarding the recycling of copper tailings are analyzed. Results indicate that CTP possesses a rougher surface, a larger specific surface area, and a more uniform pore size distribution than LP, particularly across the mesopores range. These characteristics could promote the adsorption of asphalt on its particle surface, potentially leading to enhanced filler-particle interaction. Regarding pavement performance, CTP-asphalt mastic outperforms LP-asphalt mastic in terms of high-temperature performance. Meanwhile, its low-temperature performance and moisture stability are only limitedly declined with the acceptable performance. Further, heavy metals leaching tests suggest that the risk for the substantial utilization of CTP in paving asphalt is absent. The related outcomes have verified the promising potential of CTP as an alternative candidate to substitute the conventional filler in paving asphalt from comprehensive consideration of in-service performance, and environmental and economic benefits.

Anaerobic digestion has the potential to convert organic waste materials into valuable energy. At the same time, using press water from biomass materials for energy generation while taking advantage of the resulting cake for other purposes is an emerging approach. Therefore, this study aimed to investigate the residual potential expected from a typical biogas feedstock after it has been mechanically separated into liquid and solid phases. Hence, in this study, the rumen contents of ruminants (cow, goat, and sheep) and their proportionate ratios were obtained from an abattoir in Ghana. Resource characterization of the waste samples was carried out in the central laboratory of the HFR, Germany. Anaerobic batch tests for biogas (biomethane) yield determination were set up using the Hohenheim Biogas Yield Test (HBT). The inoculum used was obtained from an inoculum production unit at the Hohenheim University biogas laboratory. The trial involved two different forms of the sample: mixture of rumen contents, press water, and inoculum, each in four (4) replicates. The trial was carried out at a mesophilic temperature of 37 °C. Results obtained over a seventy (70) day period were transformed into biogas yields. Overall, the results show that the current contents are suitable for biogas generation as an option as opposed to the current form of disposal at a refuse dump. However, using these mixtures in their original forms is more technically viable than using press water without further treatment.

Global development has led to the generation of substantial levels of hazardous contaminants, including pesticides, which pose significant environmental risks. Effective elimination of these pollutants is essential, and innovative materials and techniques offer promising solutions. This study examines the modification of natural zeolite (clinoptilolite) and fly ash-based NaA and NaX zeolites with hexadecyltrimethylammonium bromide (CTAB) to create inexpensive adsorbents for removing 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide from water. Detailed characterization of these materials was performed, along with an evaluation of the effects of pH, contact time, temperature, and initial 2,4-D concentration on their sorption capacities. The modified samples exhibited significant changes in elemental composition (e.g., reduced SiO2 and Al2O3 content, presence of Br) and textural properties. The adsorption of the pesticide was found to be an exothermic, spontaneous process of pseudo-second-order kinetics and was consistent with the Langmuir model. The highest sorption capacities were observed for samples modified with 0.05 mol L−1 CTAB, particularly for CliCTAB-0.05.

Land scarcity has prompted civil engineers to develop ground improvement techniques that enable construction, for instance, on grounds with expansive soils. Stone or granular columns inserted into the soft soil are frequently used for this purpose. In this study we investigate a ground improvement technique using multi-blended columns. Multi-blended columns contain a mix of industrial waste like fly ash, iron dust or stone dust in replacement of sand and cement as a binder. The continuously increasing volume of waste material makes it attractive for engineers to utilise such waste for construction purposes. In the present work we tried to utilise the waste in certain mixes and cast columns with these specific mixes in expansive soil. The parameters considered were the different blends of waste material in column design, different diameters of the single multi-blended column and bearing strength of single vs. groups of multi-blended columns. The experiments were conducted in the laboratory using a mould with a diameter of 15 cm and a height of 17 cm. Multi-blended granular columns using waste materials like fly ash, stone dust, iron dust, and cement as a binder were cast in moulds of 2, 3 and 5 cm diameter. The replacement technique was used for the installation of the columns in expansive soil. The column's compressive strength was compared with and without the use of iron dust. The load-deformation curve was obtained with the help of a plunger of 5 cm in the CBR machine. The encasements were made from two types of geosynthetics, i.e. geogrid and geotextile. The mix design was followed by the UCS (unconfined compressive strength) tests performed on soil samples and the granular mix of different ratios with and without iron dust called as multi-blended columns. The mix used for the design of the multi-blended granular column showed optimum compressive strength compared to the expansive soil. The SEM and XRD analysis of the materials, i.e. soil, fly ash, stone dust, iron dust, and the mix used for the multi-blended column were done. The experimental results were validated with numerical modelling using Plaxis 3D. With the Plaxis software package, finite-element analyses (FEM) were also done utilising 10-noded triangular elements. For soft clay and column mix a draining analysis was performed using Mohr-Coulomb's criterion. The numerical findings from the FEM were compared to the experimental results, and they were found to be in good agreement. There is no noticeable benefit when columns are spaced more than three times the diameter of the column. Design charts are created based on the findings, and a design procedure is offered. [ABSTRACT FROM AUTHOR]

Patching is a common pavement treatment, and it is implemented using hot and cold process patching. Hot process patching is not an efficient implementation method because keeping asphalt temperature in long hauls is difficult, on-site mixing equipment is required, and transport costs are generally high. Moreover, hot process patching requires a significant amount of energy, so it is not an eco-friendly process. Although cold process patching significantly reduces the energy consumption of patching, its implementation reduces the patching quality. To this end, this study aimed to propose a new cold process patching using induction heating. Furthermore, this study attempted to apply waste materials in the proposed mixtures to preserve the environment. Accordingly, high percentages of reclaimed asphalt pavement (RAP) were used in the proposed mixture. Since induction heating was applied in the introduced patching method, two waste materials, including steel slag and electronic waste, were utilized in the mixtures to enhance the sensitivity to electromagnetic radiation. Moreover, different experimental tests were conducted to evaluate the mixtures' mechanical properties. Ultimately, gray relational analysis was performed to assess the proposed mixtures' sustainability. The results indicated that using steel slag and electronic waste as conductive materials could considerably reduce the heating time to raise the fabricated mixtures' temperature. Moreover, replacing the Neat mixture with the proposed asphalt mixtures containing the waste materials significantly reduced the unit price, greenhouse gas emission, energy consumption, and raw material utilization. [ABSTRACT FROM AUTHOR]

In this Article, we will introduce several interrelated problems present in municipal solid waste recycling efforts, both globally and locally. The introduction serves to demonstrate how the lack of adequate global waste tracking and community-level waste contamination are related issues. This article elaborates on how these issues could be addressed with the Internet of Things (IoT), artificial intelligence (AI), and open data technology deployment. We will investigate the existing and possible applicability of this solution in resource-constrained environments, as opposed to exclusive use in the typical “smart city” context. Finally, we will discuss the risks and limitations of this approach. [ABSTRACT FROM AUTHOR]