Blended Materials Research Articles

Recycling of Disposable Face Mask: Experimental Studies on Different Types of Polymer Mixture

The COVID-19 pandemic has caused significant impacts on the environment since the use of disposable face masks leads to the accumulation of plastic waste. In this study, a two-step extrusion and injection molding was performed to manufacture polymer blends consisting of 80% used face mask and 20% fraction of one of these recycled polymer mixtures: polypropylene (PP), high-density polyethylene (HDPE), and PET. ASTM D256 standard was used to evaluate the mechanical properties of the resulting polymer blend materials, while the physical performance was assessed by analyzing the shrinkage. It was found that adding other polymeric mixtures could not enhance the mechanical properties of pure disposable face masks, as measured by the impact strength. However, incorporating the recycled polymer into the face mask mixture is revealed to decrease shrinkage. Observation of the morphology surface of the fracture impact specimen using a Scanning Electron Microscope (SEM) confirmed the less miscibility within the recycled polymer/face mask. The blend, which contains recycled PET, showed the lowest percentage of shrinkage. Taking advantage of its recyclability characteristic, this current work may provide an alternative approach for using the disposable face mask in low load-bearing applications.

Optimization of Inputs for the Application of ANN to Rail Track Granular Materials

Machine Learning (ML) models such as Artificial Neural Networks (ANN) have gained increasing popularity in geotechnical engineering applications as an alternative to conventional empirical and computational models. At present, very few ML models exist for predicting the mechanical responses of track granular materials such as ballast and subballast which may even comprise of composite mixtures of blended granular materials. Moreover, the performance of any ML model depends not only on the quality and quantity of available data but also on the selection process for input parameters, which often lacks adequate justification in the past literature. In this context, the current study introduces ANN models for track granular materials based on published laboratory data with special emphasis on the selection of an optimal set of input parameters. Two applications of ANN are considered to: (i) predict the peak friction angle (ϕpeak') of a variety of granular mixtures under static loading and (ii) predict ballast breakage under cyclic loading. The selection process involves prudent analysis of key influential parameters in a geotechnical perspective, while also ensuring that they are conveniently measurable. Performance evaluation of these models with various input combinations is carried out, while proposing optimal input parameters for both applications.

Impact of calcium carbonate whisker on chloride migration in cementitious materials blended with calcined kaolin tailings

Cement blended with aluminate and carbonate phases has demonstrated potential as a low-carbon binding material, with limestone calcined clay cement (LC3) being a prime example. Given the growing demand for building materials, it is essential to explore alternative raw materials. This study investigates the chloride resistance of cement incorporating aluminate phases from calcined kaolin tailings (CKT) and the carbonate phase from limestone/calcium carbonate whiskers (LS/CW). The rapid chloride migration test is employed to analyze the impact of CKT and its combination with CW on chloride movement. Additionally, microstructural characteristics, phase assemblage, and morphology of the hardened paste are examined using Mercury Intrusion Porosimetry (MIP), electrochemical tests, X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Results indicate that CKT and CW combined exhibit superior chloride resistance. Beyond the filler effect, the pozzolanic and aluminate-carbonate reactions effect, the bridging effect of CW enhances microstructural properties. This study highlights the potential of modifying raw material shapes to improve long-term performance of blended cementitious materials.

Impact of Impurities on the Properties of Recycled Aggregate for Use in Civil Engineering Work and Road Construction. Part 1: Technical Assessment

Abstract Construction and demolition waste (CDW) is a significant source of mineral resources. Recycled concrete aggregate fraction 0/63 mm is among the most used materials. The present study aims to evaluate the influence of impurities such as asphalt, bricks, soil, and lightweight materials on the properties of recycled aggregate. Two types of blended recycled materials are composed – one, representative for recycled aggregate from CDW generated at road projects and another type, representative for recycled materials from buildings rehabilitation and demolition. The main characteristics of blended recycled aggregate with different amounts of impurities are being investigated according to EN 13 242. The maximum dry density and optimum water content according to EN 13286-2 and the California Bearing Ratio (CBR) according to EN 13286-47 are also determined. The source of CDW is found to have a significant impact on the performance of the recycled material. The rule of mixtures and some testing methods are not always appropriate for the recycled materials. Based on the results, some recommendations regarding the management of CDW and the appropriate use of recycled aggregates in civil engineering and road construction are made.

Foam-based antibacterial hydrogel composed of carboxymethyl cellulose/polyvinyl alcohol/cerium oxide nanoparticles for potential wound dressing.

Foam-based wound dressing materials produced by dispersing gas phases in a polymeric material are soft, adapt to the body shape, and allow the absorption of wound exudate due to their porous structure. Most of these formulations are based on synthetic substances such as polyurethane. However, biopolymers have entered the field as a new player thanks to their biocompatible and sustainable nature. Incorporating biopolymers in formulations is gaining interest in scientific literature, and we extend this approach by adding antibacterial cerium oxide nanoparticles to biopolymer formulation. We introduce a novel biopolymer composite of carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and cerium oxide nanoparticles (CeO2 NPs), namely PVA-CMC@CeO2. This mixture was first foamed and then cross-linked with sodium tetraborate solution, followed by a freeze-thaw process. After the novel material's spectroscopic, structural, and morphological characterization, we investigated its swelling, drug-delivery, antibacterial, and biodegradability properties PVA-CMC@CeO2 dressing effectively inhibits Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) growth and delivers the antibiotic drug silver sulfadiazine for up to 6 h. The antibacterial properties, good swelling, and drug release profile of the blend material show promising potential in wound care applications.

Scientific advances regarding the effect of carbonated alkaline waste materials on pozzolanic reactivity

Using alkaline waste materials as biomass ash (BA), Recycled Concrete Fines (RCF) from constructions and demolition waste (CDW) and ladle furnace slags (LFS), as CO2 massive sinks worldwide through the generation of new potential SCM by Accelerated Carbonation Technologies to reduce the cement industry's carbon footprint is increasingly attracting attention for its environmental benefits and the materials' improved performance in blended cement matrices. This paper employs characterization and identification techniques (XRF, XRD–Rietveld, SEM/EDX, BET, TG/DTG, FTIR, NMR) to analyse the effect of accelerated carbonation of white ladle furnace slag, siliceous construction and demolition waste and biomass ash on those materials' physical and mineralogical properties, their chemical reactivity and their pozzolan/lime systems' mineralogical phases. The results show that although behaviour differs depending on the carbonated waste materials' alkalinity, all three present notable increases in BET surface area (7–17.5 m2/g) and substantially altered potentially carbonatable mineralogical phases (e.g. portlandite, Ca-olivine, periclase, hydrated cement phases), which mostly transition towards calcite, due to the CO2 uptake. Thermodynamic modelling of the pozzolanic reaction indicates that CSH/C(A)SH) gels are the most stable phases, followed by ettringite, C4AH13 and C4AcH12.

Characteristics of OP35E-based phase-change emulsion and its potential applications in thermal management

ABSTRACT A phase-change emulsion was prepared using OP35E (melting peak at 36.58 ℃) as the phase-change material and Span60-PEG600 blend as a compound emulsifier. This phase-change emulsion exhibited low viscosity, low subcooling, low electrical conductivity, high heat capacity, non-corrosiveness, and high stability.The viscosity, subcooling, electrical conductivity, and pH value of the emulsion were 2.67 mPa∙s, 1.03°C, 99.3 us/cm, and 7.80, respectively. No phase separation occurred after the emulsion was left to stand for 1 month. The volume average particle size increased by only 0.14 μm, Neither agglomeration nor stratification of the emulsion occurred after 400 high/low-temperature cycles. The electrical conductivity and pH value of the emulsion were determined to be 150.5 µs/cm and 7.23, respectively, indicating small variations. In the 60-day static corrosion test, the emulsion exhibited low corrosiveness to 304 stainless steel, T2 copper, and H62 brass, with corrosion amounts of 0.240 g/m2, 0.719 g/m2, and 1.438 g/m2, respectively.The melting peak of the emulsion occurred at the temperature of 35.45°C, and the enthalpy of melting was 35.28 J/g. The maximum apparent specific heat capacity of emulsion is 9.94 J/(g∙K), which is more than twice that of conventional coolants such as water and ethylene glycol. In conclusion, the OP35E-based phase-change emulsion has a high heat storage capacity and exhibits great potential application in lithium battery thermal management systems.

Wet Procedure-Driven Performance Enhancement of Poly-Crystalline Cathodes in All-Solid-State Batteries

As the demand for electrical energy continues to rise, battery systems have gained significant attention. All-solid-state batteries (ASSBs) have emerged as promising candidates for the next generation of energy storage systems due to their enhanced safety and high energy density. By replacing the flammable organic liquid electrolytes used in conventional lithium-ion batteries (LIBs) with solid-state alternatives, ASSBs offer enhanced safety features, eliminating risks of leakage, fire, and explosions. Furthermore, recent research efforts have been directed towards improving energy density by increasing the capacity of nickel-rich layered oxide cathode materials (NCM), facilitating safer and more efficient energy storage system[1].Conventional dry methods for manufacturing bulk-type electrodes in all-solid-state batteries (ASSBs) are limited in scalability, posing challenges for commercialization. Wet-slurry casting methods are essential for synthesizing large-area cathodes; however, difficulties arise due to the severe reactivity between sulfide solid electrolytes (SEs), such as Li6PS5Cl (LPSCl), and polar solvents like N-Methyl-2-pyrrolidone (NMP).Kim et al. proposed an infiltration method as a solution to address this issue. By elevating the temperature during the infiltration process, we enhance the molecular motion of the SE, facilitating its efficient incorporation into the cathode structure. This approach enabled the fabrication of a high-energy-density NCM622/Li–In half cell with a capacity of 136 mA h g-1 and a loading level of 17 mg cm-2. Electrochemical testing with cathode materials of varying particle sizes revealed that hybrid cathodes containing a mixture of large and small particles exhibited optimal SE infiltration, minimizing void formation within the electrode. Among the fabricated ASSBs, those with SE–NCM electrodes comprising a blend of active materials demonstrated superior electrochemical performance, achieving a capacity of 108.6 mA h g-1[2].In this study, a scalable infiltration sheet-type process was used to fabricate composite electrodes with different cathode-material morphologies for ASSBs. LPSCl-infiltrated polycrystalline electrodes showed an excellent retention performance and rate capability. Galvanostatic intermittent titration technique (GITT) analysis and transmission electron microscopy (TEM) confirmed severe polarization and the presence of a rock-salt-structure layer in single-crystalline cathode particles. In contrast, composite electrodes comprising polycrystalline cathode materials infiltrated with the SE LPSCl showed an excellent electrochemical performance owing to intimate electrode–electrolyte interfacial contact. The as-fabricated poly-NCM infiltration electrodes showed an excellent electrochemical performance (with an initial discharge capacity of 196 mA h g−1, a discharge capacity of 112 mA h g−1 at a high rate of 2 C, and a retention of 81 % after 30 charge–discharge cycles). The infiltration method proposed in this study could enable the fabrication of high-performance composite electrodes for ASSBs in the future.

An Analysis of Nanoparticles in Composite Materials

A blend of various materials with nano-scale dimensions is called a nanocomposite. Combining the qualities of various materials to create a unique nanomaterial with improved and increased chemical and physical capabilities is the goal of creating nanocomposites. The characteristics of nanocomposites and raw materials are very different. On comparing nanocomposites to standard composite materials, a big surface area and a remarkable surface-to-volume ratio are seen. Environmental professionals have taken an interest in these composite materials, particularly in relation to their ability to remove pesticides from various samples. This is mostly due to the many special qualities that the nanomaterials which help with pesticide remediation offer. The necessity of composite materials above conventional materials is demonstrated by this study. Composite parts are produced in several industries using various moulding techniques. The main benefits of composites are their relative stiffness, strength and lightweight. The physical characteristics, material qualities, design, tooling, inspection and repair of composites are its fundamental ideas. Strong, lightweight materials are crucial for military vehicles like rockets, helicopters and aeroplanes. In terms of mechanical qualities, the metallic components that had been utilised until that point undoubtedly performed the job, but their large weight was prohibitive. The polymer industry was expanding rapidly and aimed to broaden the market for plastics to include a wider range of applications. A potential remedy was provided by the introduction of novel, lightweight polymers from research and development facilities.

Analysis and Optimization of the Noise Reduction Performance of Sound-Absorbing Materials in Complex Environments

The acoustic performance of sound barrier absorption materials utilized in substations is subject to variations due to factors such as sandstorms, corrosion, and rainfall. In this study, a model of the absorbing material was developed based on the Delany–Bazley model using COMSOL simulation software, version 5.6. The influence of porosity and material thickness on the absorption coefficient was analyzed, and the patterns of change were summarized. The results indicated that porosity significantly affected the entire analysis frequency range, while material thickness had a more pronounced impact in the low-frequency range. Building upon these findings, a blended fiber absorption material was formulated through research efforts. Experimental results demonstrated that the aluminum fiber diameter measured 30 microns, while the aramid fiber diameter was 12 microns; additionally, their mass ratio was established at 3:1. The material thickness was determined to be 10 cm with a face density of 2500 g/m2, resulting in optimal absorption performance. Durability tests revealed that this material could sustain effective acoustic performance across various complex environments. Finally, simulations and analyses regarding noise reduction effects were conducted within actual application scenarios; it was found that the noise reduction capability of the blended fiber sound barrier absorption material exceeded that of glass wool by 4.78 dB.

The Flexural Strength and the Effect of the Autoclave Sterilization of Polypropylene/Natural Rubber Blended Materials.

Background: Rubber dam clamps are used extensively in dentistry, especially during root canal treatment. However, existing rubber dam clamps have several drawbacks, including discomfort and potential damage to vital tissue in the oral cavity. To address these existing issues, a new rubber dam clamp should be developed. The aim of this study was to identify the optimum ratios of polypropylene and natural rubber (PP/NR) for a customized rubber dam clamp in dentistry. This study was focused on the flexural strength of PP/NR in various ratios. Moreover, the impact of autoclave sterilization was also considered. Methods: Six proportions of PP/NR blends (100/0, 90/10, 80/20, 70/30, 60/40 and 50/50) were prepared and assessed for flexural strength using a three-point bending test. After this test, the PP/NR blends with 100/0, 90/10 and 80/20 ratios were selected and underwent autoclave sterilization for 1, 5 and 10 cycles. Eventually, the flexural strength testing was repeated and investigated. An analysis of variance and Tukey's test were used to evaluate the flexural strength of various PP/NR blends before autoclave sterilization at p < 0.05. An analysis of variance and Dunnett's T3 test were used to evaluate the flexural strength of selected PP/NR blends before and after autoclave sterilization at p < 0.05. Results: The results revealed that the flexural strength of PP/NR blended materials showed a statistically significant difference in every group of this study. The autoclave sterilization test revealed that the flexural strength of the PP/NR 90/10 and 80/20 ratios was significantly increased after sterilization for 1, 5 and 10 cycles. In addition, the PP/NR 90/10 ratio was also comparable to the 100/0 ratio. The lower NR content in PP/NR blends resulted in significantly higher flexural strength, and autoclave sterilization had an effect on this property. Conclusions: This study suggested that the PP/NR blend with a 90/10 ratio might be considered as an alternative material for developing rubber dam clamps.

Utilization of coalmine overburden-furnace slag and fly ash mixed cement-treated subbase/base course material for sustainable flexible pavements: mechanical performance and environmental impact.

The scarcity of conventional aggregates with tremendous growth in highway construction and the indiscriminate dumping of industrial waste materials in precious landfills has become a huge global concern. This study is aimed at utilizing wastes from various industries, including coalmine overburden (OB) dump, basic oxygen furnace (BOF) slag, and fly ash to produce suitable and sustainable cement-treated subbase/base course layers (CBSB/CTB) for flexible pavement construction. Response surface methodology was used to optimize the composition of the blended material considering unconfined compressive strength (UCS) and Poisson's ratio. Results demonstrated that 50% OB dump, 40% slag, 5% fly ash, and 5% cement achieved a 7-day UCS of 4.84MPa and Poisson's ratio of 0.25, in line with IRC:37-2018 guidelines. X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) analysis confirmed the presence of ettringite crystals, calcium-silicate-hydrate (C-S-H), and calcium-aluminosilicate-hydrate (C-A-S-H) gels which are the source of strength development in the blend. Further, a soaked California bearing ratio (CBR) of 136.08% and flexural strength of 2.06MPa after 7days and 28days of curing, respectively, demonstrates the overall strength of the stabilized waste. Approximately 4% weight loss was observed after wet-dry durability tests, indicating exceptional performance of the optimal blend in inclement weather conditions. Furthermore, the environmental impact of the blended material was studied through a leaching study. Fly ash had a high zinc (Zn) level, while BOF slag showed a rich concentrationof chromium (Cr), manganese (Mn), and iron (Fe) in the acid digestion test. In spite of this, the toxicity characteristics leaching procedure (TCLP) test indicated that the levels of heavy metals that leached from the stabilized material stayed considerably below the permissible limits set forth in Indian Standard, IS:10500 (2012). Finally, cost analysis showed a 51.6% reduction in construction cost with cement-treated industrial wastes instead of granular base/subbase made with conventional aggregates. The study recommends the suitability of the stabilized waste material as an alternate construction material for large-scale field applications, which could encourage the construction of flexible pavements that are environmentally benign, economical, and sustainable.

University instructors’ and students’ perceptions of blended learning and perceived determinant factors

The purpose of this study was to examine the perceptions of instructors and students towards blended learning and perceived determinant factors at Jimma University. A concurrent mixed-methods research design was used. Data were collected from 145 students and 70 instructors by using questionnaires and interviews. The findings showed that both instructors and students confirmed the lack of facilities, lack of technological knowledge, and instructors’ lack of technological pedagogical knowledge. On the other hand, both instructors and students believed that the BL approach had a positive impact on students learning. In addition, the major challenges identified were teachers’ increasing workload, lack of access to internet connections, non-compliance of learners’ educational backgrounds to permit effective use of BL, non-suitability of the approach for all learning styles, slow internet connectivity, lack of organization of blended learning materials, and lack of IT knowledge. Based on the findings of the study, it is recommended that the concerned university officials give thoughtful attention to the provision of necessary facilities to implement BL and design appropriate training and capacity-building programs for university instructors and students to increase students' and instructors’ knowledge and skills in technology use. Keywords: Blended learning; challenges; determinant factors; instructors; perceptions

Optimization of Barrier Properties of PLA/PBAT Polymers in Biodegradable Materials

AbstractDespite its popularity as a bio‐based biodegradable material, polylactic acid (PLA) has a number of shortcomings. Nevertheless, the combination of poly(butylene adipate co‐terephthalate) (PBAT) and thermoplastic starch (TPS) to enhance the mechanical properties of PLA was achieved through the utilisation of PLA/PBAT/TPS ternary composites, which were created through the calendering method. These composites exhibit advantageous characteristics, including high ductility, enhanced toughness, and biodegradability. The results of the water vapour permeability test indicate that the proportion of the material composition exhibiting the lowest value of water vapour permeability is 2.0571 g/m²·24h. The results of the water vapour transmission test demonstrate that the material generated by the composition ratio has the lowest water vapour transmission, indicating that the composite material blending effect is superior. The majority of current research employs nanocellulose as a substrate in PLA, with a paucity of studies investigating its use in PLA/PBAT/TPS composites. These composites are modified due to the notable divergence of nanocellulose from the hydrophobicity of the composite and its susceptibility to decomposition at elevated temperatures. This study establishes a foundation for future research in this field.

Vertical Response of Stress Transmission Through Sand–Tire Mixture Under Impact

This study evaluates the vertical stress transmission through a sand–tire mixture layer under impact, focusing on this innovative blended material that can impact underground structures such as tunnels or pipelines. By conducting consolidated undrained triaxial tests, the friction angle (φ) of the sand–tire mixture was determined, ranging from 29° for pure tire to 41° for pure sand. The vertical stress factor (α), representing the ratio of response load to applied load, was found to decrease significantly with increased tire content, with a reduction of up to 50% for mixtures containing 20% tire. Additionally, the vertical stress response decreased from 35 kPa for pure sand to as low as 15 kPa for mixtures with a high tire content under a consistent applied load of 65 kPa. This study not only presents a methodological advancement in analyzing sand–tire mixtures under dynamic loads but also suggests a sustainable approach to utilizing waste tire material in civil engineering projects, thereby contributing to environmental conservation and improved material performance in geotechnical applications.

Study on Phase Change Materials' Heat Transfer Characteristics of Medium Temperature Solar Energy Collection System.

Within the next five years, renewable energy is expected to account for approximately 80% of the new global power generation capacity, with solar power contributing to more than half of this growth. However, the intermittent nature of solar energy remains a significant challenge to fully realizing its potential. Thus, efficient energy storage is crucial for optimizing the effectiveness and dependability of renewable energy. Phase-change materials (PCMs) can play an important role in solar energy storage due to their low cost and high volumetric energy storage density. The low thermal conductivity of PCMs restricts their use for energy storage, despite their immense potential. Hence, the primary goal of this study is to experimentally investigate the energy storage capacity of two blended phase-change materials (paraffin and barium hydroxide octahydrate) through integration with a medium-temperature solar heat collection system. The experimental findings reveal that the blended PCMs possess the highest cumulative charge fraction (0.59), energy capacity, and low energy loss compared to each PCM alone. Furthermore, the phase change storage tank achieves higher heat storage (27%) and exergy storage efficiency (18%) compared to the stored tank water without any PCMs. The blended PCMs enhanced their performance, exhibiting improved interaction and excellent thermal storage properties across a range of temperatures, offering an opportunity for the design of an energy-efficient, low-cost storage system.

Investigating the Influence of Protic Ionic Liquid on the Triboelectrical Properties of Trimethylolpropane Trioleate (TMPO)

Under triboelectric conditions, where tribocharging accelerates lubrication failure, lubricants with enhanced electrical properties are essential. Trimethylolpropane Trioleate (TMPO) oil, derived from esters that possess good lubricating properties and wear performance but is lacking in terms of electrical properties which can be further improved when blended with Ionic Liquid. This study blends 1 – 5 wt% of Protic Ionic Liquid (PIL) into TMPO and evaluate the frictional and wear performances of the blends under 1 – 2 A current conditions to understand the behaviour towards the tribological properties of different blends of material. Electric currents ranging around 1 – 2 A are implemented to the custom-designed ball-on-disc tribometer, with a constant 4.5 V voltage supply and the static resistance are measured. Mechanical wear properties are observed after the tribological test with different samples. The frictional properties of all concentrations of PIL in TMPO showed significant frictional improvements with 1%wt PIL showed 53% better results indicating improvements in frictional properties and wear performance under 2A current conditions, owing to its lowest film resistivity of 0.14 mΩ.

Fresh and Hardened Properties of Alkali-Activated POFA-GGBFS Pastes Cured in Ambient Temperature – An Initial Mix Design

Weak soils are characterised by their high compressibility and low shear strength, which requires stabilisation to improve their compaction and strength characteristics before being used for construction projects. Recent trends in soil stabilisation show an increased interest in the application of waste-derived geopolymers as low-carbon materials to address the carbon emission problem related to cement production. This paper presents the preliminary findings of using Palm Oil Fuel Ash (POFA) and Ground Granulated Blast Furnace Slag (GGBFS) binary blends as geopolymer precursor materials. These binary waste material blends were activated using alkaline solutions, namely Sodium Hydroxide (NH) and Sodium Silicate (NS), to synthesise geopolymers at ambient temperatures. Three main factors were considered for the optimisation of the geopolymer mix design, as recommended by past research: alkali equivalent (8-11.5%), activator modulus (0-0.7), and slag replacement (fixed at 30%). Alkali equivalent and activator modulus parameters were varied and tested to establish its initial and final setting times, workability and strength properties, while the slag replacement percentage was set at 30%. This study aimed to determine the most influential parameters to produce the geopolymer material with the highest compressive strength and satisfactory setting times and workability. Single-source alkali activators (NH only) used on POFA-GGBFS produced specimens with smaller flow diameters, longer initial and final setting times, and lower compressive strength than specimens activated with NH and NS. Geopolymer specimens synthesised with NH and NS produce stiffer compounds possessing higher compressive strength values and explosive-type failure modes due to their higher silica content. At ambient temperatures, TM-Mix 2 (7% alkali equivalent and 0.7 activator modulus) produced the highest compressive strength value of 67.3 MPa at 28 days curing, flow diameter of 227 mm, with the initial and final setting time of 25 minutes and 45 minutes, respectively. Consequently, the results show that the preliminary POFA-GGBFS geopolymer mix design could produce sustainably sourced geopolymer compounds with adequate strength and acceptable setting time and workability. This study is part of a current investigation to further optimise the POFA-GGBFS mix design for the purpose of weak soil stabilisation.

Valorization and investigation of volcanic ash as an aggregate building brick component

Abstract The devastating series of Taal volcanic eruptions from 2020 to 2022 covered several locations in the Philippines under a thick layer of ashes, destroying properties and halting business operations. In response, the Biñan City Government in Laguna, Philippines, proposed the development of eco-friendly bricks by leveraging the pervasive amounts of spewed volcanic ash as part of its solid waste management program. The materials recovery facility of the city produced several brick blends of combined Taal volcanic ash, cement mortar, and plastic waste materials. This study investigates the potential of Taal volcanic ash as an aggregate building brick component by measuring the compressive strength of the formulated bricks. With different blends of aggregate components, the bricks were tested for their durability based on the ASTM C67/C67M-20 standard after curing between 15 to 30 days. Per the ASTM C62-17 standard, all brick blends that were cured for 30 days including those with volcanic ash and plastic waste as aggregate components fall under the negligible weathering grade. This indicates that these bricks will be durable in building and structural applications where the average compressive strength requirement for bricks is at least 10.3 MPa. A regression model was also fitted with an adjusted r 2 value of 0.9413 and a p-value of &lt; 2.2 × 10−16 using the experimental data.

Effect Of Post-Curing Treatment Temperature On The Tensile Strength And Impact Resistance Of Coconut Fiber-Reinforced Polyester Composites

Composite material is an engineered material created by combining two or more materials to produce enhanced mechanical properties compared to its constituent materials. This study focuses on natural fiber composites using coconut fiber as reinforcement with a polyester matrix. Post-curing treatment is applied to improve the mechanical strength of the composite. Post-curing is a heating process at a specific temperature aimed at enhancing the properties of the composite. The purpose of this research is to determine the effect of post-curing temperature on the impact strength of polyester-coconut fiber composites. The specimens were fabricated using the mixing method for material blending and hand lay-up for composite formation, following the standards of ASTM D638-02 Type I and ASTM D256 for impact testing. The specimens were heated in an oven at various temperatures: non-post curing, 110°C, 120°C, and 130°C, each for one hour. Impact testing was conducted using a Mory Testing Machine. The results showed that the composite with a post-curing temperature of 120°C achieved optimum tensile strength of 9.2 N/mm² and impact strength of 0.1663 J/mm². Based on these findings, the polyester-coconut fiber composite can be used as material for particleboard type 100 and meets the SNI 03-2105- 1996 standards for tensile and impact strength. Additionally, this composite has the potential to be used as an alternative material for manufacturing SNI-standard helmet