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In civil construction, one of the primary challenges associated with wood application is its high flammability and low durability during fires. Although chemical treatment with fire-retardant properties exists, they are expensive and of non-renewable origin. Tannin, a wood extractive, being a phenolic compound, holds promise for enhancing the thermal properties of wood. This study aimed to assess the efficacy of tannin as a fire retardant and compare it with a commercial product, as well as comparing different application techniques for these products. Wood samples from the Simarouba amara Aubl. species were utilized. Tannin and a commercial flame retardant were applied via immersion, vacuum impregnation, brushing, and a treatment of tannin incorporated into water-based wood varnish. Alongside the burning test performance, assessments of the wood's physical properties, such as colorimetry, thermal stability, and mass retention, were conducted. The application of tannin altered the wood's color and reduced the spread of fire; its presence significantly reduced the flame duration and maintained the wood's structural integrity. However, tannin retention was lower compared to commercial flame retardant, leading to reduced fire retardancy. Among the methods tested, immersion proved to be the most effective in enhancing the wood's resistance to flame contact. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the parameters controlling auto-ignition, degradation and auto-extinction of wood. For this purpose an extensive set of experiments was conducted varying extrinsic parameters such as external heat-flux but also the type of wood. Varying the wood species allowed to explore the role of thermal properties and wood composition. Seven wood samples were tested, some light and some heavy, both hardwood and softwood. The experimental setup was based on a double-cone calorimeter, which allowed to accurately change the imposed heat flux at a predefined moment. More than 600 tests were carried out in a vertical orientation, allowing a statistical analysis. For each test, mass loss, surface temperature and in-depth temperature of the samples were measured using a precision scale, an infrared camera and thin wire thermocouples embedded using a special machining, respectively. The auto-ignition study showed that the time to auto-ignition increases linearly with density. Despite a wide range of these times to ignition, the surface temperatures at ignition were in the same order of magnitude for all species considered: between 450 and 700 °C for auto-ignition before 2 min and between 700 and 800 °C for auto-ignition after 2 min. The onset of char oxidation was observed at low heat fluxes. It occurs at different times depending on the wood species, but at similar surface temperatures, between 380 and 400 °C. The sliding double heating cone made it possible to identify the criteria for auto-extinction: the heat flux for auto-extinction can vary from 40 to 55 kW.m−2 depending on the wood species, and a linear correlation was found between the mass loss rate at extinction and the initial density of each sample studied. The study highlights the dominant role of density for auto-ignition and auto-extinction. • Study of fire behavior in vertical orientation by 600 tests at the cone calorimeter scale. • Comparison of piloted and spontaneous ignition as well as surface temperature at ignition of 7 wood species through more than 150 tests. • Study of the degradation of seven species of wood by measuring the surface temperature, in-depth temperatures and mass loss rate for five heat fluxes. • Study of flame extinction conditions for the seven wood species (critical heat flux and critical mass loss rate). [ABSTRACT FROM AUTHOR]

Polymer composites especially bio composites can be manufactured using different combination of matrix and fiber-reinforcement materials and produces different properties for different combinations. But with the usage of natural fibers and certain matrix materials, it leads to moisture absorption in these materials which causes deterioration of bonding between matrix and fiber. This can lead to reduction in tensile properties, flexural properties, and impact properties of the composite. This problem can be overcome by using chemical-treated fiber, coating fiber, or composite with suitable materials, addition of certain fillers in the composite, or by hybridizing the fibers used as reinforcement in the composite. In this present study, various factors affecting moisture absorption by a composite, its effect on the properties of the composite, different liquids which can get absorbed by the composite, models used to study moisture absorption, and methods to reduce moisture absorption in the composite are discussed. [ABSTRACT FROM AUTHOR]

Plant-based hemp natural fibre-reinforced composites are sustainable in the view of the environment. However, these composites have not attracted many applications due to their less mechanical properties compared to the synthetic fibre-reinforced composites. The present work reports the hemp fibre-reinforced composite loaded with cellulose-based filler to improve their mechanical properties. At equal proportions of cellulose filler such as pistachio shell powder, teak wood powder, groundnut shell powder reinforced with the hemp fibre-reinforced epoxy composite, the improvement in the tensile strength, flexural strength, % of elongation and % of deformation is reported. The hemp fibre/epoxy composite loaded with 5 wt% of pistachio shell powder shows a 9.28% increment in tensile strength, 50.96 % increment in flexural strength compared to hemp fibre/epoxy composite. The hemp/epoxy composite loaded with 5 wt% teak wood powder particles shows enhancement in tensile, flexural by 31.56 %, 35.97%, respectively. The hemp/epoxy composite loaded with 5 wt% groundnut shell powder particles shows enhancement in tensile, flexural by 42.99 %, 83.99%, respectively. [ABSTRACT FROM AUTHOR]

This study was focused on developing and evaluating the impacts of wood and graphite fillers on an E-glass fibre-reinforced polyester composite. The fillers employed in this study include teak, casuarina, psuedon wood dust, graphite, and hybrid fillers such as casuarina and graphite fillers. They tested for tension, flexural, impact, hardness, and dynamic mechanical analysis. In the current work, the optimum loading level is 15 wt% which was determined through testing at various loading levels. The experimental results have shown that the mechanical, physical, and thermomechanical properties of glass fiber reinforced polyester composites improvement mechanism analysis depend upon chemically treated wood dust fillers by avoiding surface delamination during fabrication. By using the hand layup method, composites were created by maintaining the fibre constant while distributing the fillers following the rule of mixture; a hybrid composite has a filler distribution of 1:1. Hybrid composite has exhibited increased flexural strength and hardness by 72.77%, 63.33% compared to casuarina wood of 15 wt% by avoiding incompatibility of casuarina wood filler with the resin. The glass transition value of the hybrid composite was increased by 1.4% compared to the above said casuarina wood composite, making it a more thermally resistant material. The hardness of the hybrid composite has increased by 2.78% compared to the teak wood of 15 wt% composite. [ABSTRACT FROM AUTHOR]

Buildings consume significant energy, much of which is used for heating and cooling. Insulation reduces undesired heat transfer to save on heating and cooling energy usage. Radiant barriers are a type of insulation technology that reduces radiant heat absorbed by a structure. Applying radiant barriers to buildings reduces costs and improves both energy efficiency and occupant comfort. However, homes often have favorable thermal gradients that could also be used to reduce energy usage if the insulation properties were switched dynamically. This article introduces two dynamic radiant barriers intended for residential attics, which can switch between reflecting and transmitting states as needed. These radiant barriers are manufactured as a single deformable assembly using sheet materials and are compatible with various actuation mechanisms. The efficacy of these radiant barriers is reported based on a hotbox experiment and numerical calculations. The experimental results demonstrate that both proposed dynamic radiant barrier designs increase effective thermal resistance by factors of approximately 2 when comparing insulating to conducting states, and by approximately 4 when comparing the insulating state to the case without a radiant barrier. Additionally, the dynamic radiant barriers achieve heat flux reductions up to 41.9% in the insulating state compared to tests without a dynamic radiant barrier. [ABSTRACT FROM AUTHOR]

A significant waste material threatening sustainability efforts are post-consumer food packaging goods. These ubiquitous multi-materials comprise chemically disparate components and are thus challenging targets for recycling. Herein, we undertake a proof-of-principle study in which we use a single-stage method to convert post-consumer multi-material food packaging (post-consumer peanut butter jars) to a high compressive strength composite (PBJS90). This is accomplished by thiocracking the ground jar pulp (10 wt. %) with elemental sulfur (90 wt. %) at 320 °C for 2 h. This is the first application of thiocracking to such mixed-material post-consumer goods. Composite synthesis proceeded with 100% atom economy, a low E factor of 0.02, and negative global warming potential of −0.099 kg CO2e/kg. Furthermore, the compressive strength of PBJS90 (37.7 MPa) is over twice that required for Portland cement building foundations. The simplicity of composite synthesis using a lower temperature/shorter heating time than needed for mineral cements, and exclusive use of waste materials as precursors are ecologically beneficial and represent an important proof-of-principle approach to using thiocracking as a strategy for upcycling multi-materials to useful composites. [ABSTRACT FROM AUTHOR]

Lightweight engineered trusses support sustainable construction with the benefits of mass production and fast construction at lower costs. However, the truss system has raised concerns due to premature failure in fire conditions. This study investigates the effect of a thin soot layer on the surface of the gusset plate and the teeth of the gusset plate on the temperature development within lightweight wood specimens in fire conditions. A 10 cm long, 8.9 cm wide, and 3.8 cm thick dimensional lumber (often called 2 by 4) partially covered by a gusset plate was exposed to a constant incident radiant heat flux. A total of 12 experiments were conducted with four different configurations, bare gusset plates with and without teeth and soot-coated gusset plates with and without teeth, at three different external radiative heat fluxes of 10, 15, and 20 kW/m2. The exposure durations were set to be 60, 40, and 30 min, respectively, to allow the total applied amount of radiant energy for each specimen to be identical. Three thermocouples were installed at a depth of 13 mm from the exposed wooden surface: two beneath the gusset plate and one below the uncovered wooden surface, and an additional thermocouple was between the gusset plate and the wood surface. The obtained temperature data showed that soot-coated gusset plates absorb significantly more radiation and record higher temperatures within the specimens than the specimens with the bare gusset plates. It was also found that the bare gusset plate works as a protective layer for the wood at 20 kW/m2, but not at 10 and 15 kW/m2. The teeth certainly contributed to heat transfer increasing the temperatures within the wood higher than those without teeth, but the effect was only meaningful for the soot-covered specimens. Connection strength was also qualitatively analyzed and it was discovered that the bare specimen retained a strong connection between the gusset plate and wood. In contrast, the soot-coated specimen was easily removed by hand, even when exposed to the same heat flux. Applying these results to a realistic scenario, this loss in connection strength could result in truss failure and structural collapse, which may result in injury to or even death of the responding firefighters. Additional gusset plate protection measures may be necessary to prolong the connection strength and prevent structural collapse. [ABSTRACT FROM AUTHOR]

This study aims to investigate the potential of integrating natural biochar (BC) derived from eggshell waste into flexible polyurethane (FPU) foam to enhance its mechanical and acoustic performance. The study explores the impact of incorporating BC at various weight ratios (0.1, 0.3, 0.5, and 0.7 wt. %) on the properties of the FPU foam. Additionally, the effects of modifying the BC with (3-aminopropyl)trimethoxysilane (APTMS) at different ratios (10, 20, and 30 wt. %) and the influence of diverse particle sizes of BC on the thermal, mechanical, and acoustic characteristics of the FPU composite are investigated. The functional groups, morphology, and elemental composition of the developed FPU composites are analyzed using Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FESEM), and energy-dispersive X-ray (EDX) techniques. Characteristics such as density, gel fraction, and porosity were also assessed. The results reveal that the density of FPU foam increased by 4.32% and 7.83% while the porosity decreased to 50.22% and 47.05% with the addition of 0.1 wt. % of unmodified BC and modified BC with 20 wt. % APTMS, respectively, compared to unfilled FPU. Additionally, the gel fraction of the FPU matrix increases by 1.91% and 3.55% with the inclusion of 0.1 wt. % unmodified BC and modified BC with 20 wt. % APTMS, respectively. Furthermore, TGA analysis revealed that all FPU composites demonstrate improved thermal stability compared to unfilled FPU, reaching a peak value of 312.17°C for the FPU sample incorporating BC modified with 20 wt. % APTMS. Compression strength increased with 0.1 wt. % untreated BC but decreased at higher concentrations. Modifying BC with 20% APTMS resulted in an 8.23% increase in compressive strength compared to unfilled FPU. Acoustic analysis showed that the addition of BC improved absorption, and modified BC enhanced absorption characteristics of FPU, reaching Class D with a 20 mm thickness. BC modified with APTMS further improved acoustic properties compared to the unfilled FPU sample (Class E), with 20% modification showing the best results. These composites present promising materials for sound absorption applications and address environmental issues related to eggshell waste. [ABSTRACT FROM AUTHOR]

Wood sandwich panels are widely utilized in residential, commercial, and industrial settings due to their excellent thermal insulation characteristics, ease of installation, and high strength-to-weight ratio. This review provides an overview on experimental outcomes demonstrating the structural integrity and versatility of wood sandwich panels. It highlights recent advancements in meeting payload requirements and their effectiveness in reducing costs and weights for prefabricated houses. The review focuses on structural applications and material efficiency, showcasing their roles in lightweight, durable constructions for retrofitting and new projects. The potential of novel, sustainable materials in construction is explored, addressing current challenges and emphasizing the diverse applications and environmental benefits of wood-based sandwich panels, underscoring their importance in advancing energy-efficient and sustainable construction. [ABSTRACT FROM AUTHOR]

The main aim of the present work is to evaluate and characterize the mechanical, morphological and thermal properties of wastes coming from the textile industry, mainly composed of cotton and polyester. These wastes will be thereafter implemented in commodity plastic such as polyamide, in order to develop new formulations of environmentally friendly materials. The composites were produced by extrusion and injection-molded processes in amounts between 15 wt.% and 60 wt.% of textile waste. With the objective of improving the properties of the materials, silanes were used as a compatibilizer between the textile fibers and the polymeric matrix. The effect of the compatibilizer in the composites was studied together with the effect of the amount of textile fiber added to the composites. Mechanical, thermal, morphological and wettability properties were analyzed for each composite. The results show that the use of silanes improves the interaction especially in those composites with a higher amount of textile waste, offering a balanced mechanical behavior with significantly high quantities. On the other hand, the melting temperature does not vary significantly with the introduction of silanes and textile waste content, although the incorporation of textile waste slightly reduces up to 23% the degradation temperature of the resulting composites. The wettability of the composites is also increased up to 16% with the incorporation of textile waste. Finally, the appearance of the composites with textile waste is strongly influenced by the incorporation of the reinforcement, offering shades close to dark brown in the whole range of compositions. [ABSTRACT FROM AUTHOR]

The increasing global commitment to carbon neutrality has propelled a heightened focus on sustainable construction materials, with wood emerging as pivotal due to its environmental benefits. This review explores the development and application of eco-friendly polymer nanocomposite coatings to enhance wood's fire resistance, addressing a critical limitation in its widespread adoption. These nanocomposites demonstrate improved thermal stability and char formation properties by integrating nanoparticles, such as nano-clays, graphene oxide, and metal oxides, into biopolymer matrices. This significantly mitigates the flammability of wood substrates, creating a robust barrier against heat and oxygen. The review provides a comprehensive examination of these advanced coatings' synthesis, characterization, and performance. By emphasizing recent innovations and outlining future research directions, this review underscores the potential of eco-friendly polymer nanocomposite coatings as next-generation fire retardants. This advancement supports the expanded utilization of wood in sustainable construction practices and aligns with global initiatives toward achieving carbon neutrality. [ABSTRACT FROM AUTHOR]

This article presents the results of research on the development of chemically resistant polymer–mineral casting composites based on industrial waste. The aim of this work is to develop a technological basis for obtaining effective inorganic fillers and highly filled composites for use in chlorine-containing environments. On the basis of theoretical data, mineral fillers and a polymer binder for filling composites were selected, optimal quantities of input hardeners and an appropriate thermal curing mode were determined, and the influence of the filling degree on the properties of composites was studied. The influence of various factors on the properties of the obtained composites was also studied, and the possibility of using local raw materials to obtain special-purpose composites was investigated. Ash from a thermal power plant (TPP) was used as an acid-resistant filler in composites. Two components were chosen as binders: phenol formaldehyde resin and mineral filler (TPP ash). As the third component, hydrolytically active fillers—anhydrite, phosphogypsum and phosphate slag—were used. The degree of filling has a significant influence on the properties of composites, including the compressive strength, chemical resistance and degree of curing, the values of which were elucidated across a wide range of composite variations based on the degree of filling. The conducted research allowed us to establish the limit of admissible anhydrite content, which should not exceed 15 mas.%. To optimize the chemical resistance and durability of the composites of the investigated substances, the method of mathematical planning was used. According to the results of this study, the optimal compositions of composites, in terms of anhydrite, phosphogypsum and phosphorus slag contents, were selected. At the maximum possible degree of filling, these composites exhibit high target characteristics. [ABSTRACT FROM AUTHOR]

All-cellulose composites (ACCs) have been fabricated by using a variety of cellulosic sources, versatile technologies, and are sustainable alternatives for traditional composites. In this study, nonwoven-woven ACC laminates were created from wood-based Spinnova short fibers and Lyocell fabrics via partial dissolution and an NaOH-urea solvent system. The less-known wood-based Spinnova fiber is created for the textile industry, but it also has great potential for the composite industry. To identify the mechanical properties of ACCs--which greatly influence the range of material application--tensile, impact, and flexural tests were conducted. The mechanical properties indicated only moderate properties, which are influenced by high porosity and weak fiber bonding. Despite this, valuable information on the nonwoven-woven structured ACCs was obtained. To improve the ACC laminate's ability to resist moisture, biobased coatings (e.g., commercially available birch bark betulin and suberin acid mixture) were applied on the surface of ACCs and it successfully improved the wetting resistance. The results of contact angle analyses demonstrated that the highest contact angle of 128° was measured for betulin-coated laminates and the best stable hydrophobicity calculated a minute after the beginning of the experiment were observed at 109° for the uncommercial pressurized hot ethanol (PHE) extract of birch bark. [ABSTRACT FROM AUTHOR]

This study involved the optimization of the molded pieces manufacturing process from a poly-3-hydroxybutyrate-co-3-hydroxyvalerate biocomposite containing 30% wood flour by mass. The amount of wood flour and preliminary processing parameters were determined on the basis of preliminary tests. The aim of the optimization was to find the configuration of important parameters of the injection process to obtain molded pieces of good quality, in terms of aesthetics, dimensions, and mechanical properties. The products tested for quality were dog bone specimens. The biocomposite was produced using a single-screw extruder, whereas molded pieces were made using an injection molding process. The Taguchi method was applied to optimize the injection molding parameters, which determine the products quality. Control factors were selected at three levels. The L27 orthogonal plan was used. For each set of input parameters from this plan, four processing tests were performed. The sample weight, shrinkage, elongation at break, tensile strength, and Young's modulus were selected to assess the quality of the molded parts. As a result of the research, the processing parameters of the tested biocomposite were determined, enabling the production of good-quality molded pieces. No common parameter configuration was found for different optimization criteria. Further research should focus on finding a different range of technological parameters. At the same time, it was found that the range of processing parameters of the produced biocomposite, especially processing temperature, made it possible to use it in the Wood Polymer Composites segment. [ABSTRACT FROM AUTHOR]

Particleboards have gained attention in the global market. Understanding their physical–mechanical behavior in the current technological context is essential due to adhesive polymerization, which depends on variables such as pressing time and temperature. Today, the use of nanoparticles has become a plausible option for improving the properties of polymers used in wood-based composites. This study evaluates the influences of the addition of non-commercial 0.5% aluminum oxide (Al2O3) and aluminum oxide copper (CuO) nanoparticles using a greener route with a lower environmental impact obtaining a urea-formaldehyde (UF)-based polymeric adhesive to manufacture particle composites of Eucalyptus urophylla var. grandis wood. Regarding characterizations, the resin properties analyzed were viscosity, gel time, and pH, as well as panel properties, including density, moisture content, thickness swelling, modulus of elasticity, modulus of rupture, and thermal conductivity. The results were compared with scientific publications and standards. The addition of nanoparticles interfered with viscosity, and all treatments indicated a basic pH. It was not possible to determine the gel time after 10 min. Nanoparticles added to the polymers in the internal layer did not cause an improvement in the swelling properties in terms of thickness, with no significant statistical difference for density and moisture content. The increase from 150 °C to 180 °C may have caused an improvement in all physical–mechanical properties, indicating that the higher temperature positively influenced the polymerization of the formaldehyde-based adhesive. Therefore, the additions of both nanoparticles (0.5% in each condition) led to a limitation in the material influence with respect to physical–mechanical performance. [ABSTRACT FROM AUTHOR]

The growing need for materials that are eco-friendly and sustainable in the industrial sector has shifted focus from synthetic fossil to natural fibers, alongside the utilization of recycled polymer textiles. This research introduces a novel method for using end-of-life textiles, such as polyester and polyamide fabrics, in the production of composite materials, aiming to lessen textile waste and enhance material longevity. The mechanical attributes of flax fabric (FF), flax–recycled polyamide fabric (F/RPA), and flax–recycled polyester fabric (F/RPES) composite laminates are assessed through tensile, flexural, interlaminar shear, and Charpy impact tests. The study revealed that the addition of end-of-life synthetic fibers improves tensile strength, while the trend in modulus values suggests that flax provides a high degree of stiffness to the composites, which is moderated by the addition of synthetic fibers. This effect is consistent across both tensile and flexural testing, although the impact on stiffness is more significant in bending. The inclusion of polyester fibers in the composite laminate resulted in significant enhancements, with an 11.1% increase in interlaminar shear maximum force, a 17.4% improvement in interlaminar shear strength, and a 67.1% rise in un-notch impact energy, compared to composites made with only flax fiber (FF). The microscopic examination uncovered the internal structure and demonstrated a clear, strong bond between the polyester and polyamide fiber layers with the flax fibers. Additionally, the life cycle assessment revealed that the F/RPES composite had less environmental impact than FF and F/RPA in all 18 categories analyzed. This indicates that the environmental footprint of producing F/RPES is smaller than that of both FF and F/RPA. [ABSTRACT FROM AUTHOR]

High-temperature vapour-phase acetylation (HTVPA) is a simultaneous acetylation and heat treatment process for wood modification. This study was the first investigation into the impact of HTVPA treatment on the resistance of wood to biological degradation. In the termite resistance test, untreated wood exhibited a mass loss (MLt) of 20.3%, while HTVPA-modified wood showed a reduced MLt of 6.6–3.2%, which decreased with an increase in weight percent gain (WPG), and the termite mortality reached 95–100%. Furthermore, after a 12-week decay resistance test against brown-rot fungi (Laetiporus sulfureus and Fomitopsis pinicola), untreated wood exhibited mass loss (MLd) values of 39.6% and 54.5%, respectively, while HTVPA-modified wood exhibited MLd values of 0.2–0.9% and −0.2–0.3%, respectively, with no significant influence from WPG. Similar results were observed in decay resistance tests against white-rot fungi (Lenzites betulina and Trametes versicolor). The results of this study demonstrated that HTVPA treatment not only effectively enhanced the decay resistance of wood but also offered superior enhancement relative to separate heat treatment or acetylation processes. In addition, all the HTVPA-modified wood specimens prepared in this study met the requirements of the CNS 6717 wood preservative standard, with an MLd of less than 3% for decay-resistant materials. [ABSTRACT FROM AUTHOR]

This article summarizes findings in the field of the history, composition, and mechanical properties of WPCs (wood–plastic composites) formed by combining two homogeneous substances, i.e., a polymer matrix with cellulose fibers in a certain ratio (with the addition of additives). In relation to a wide range of applied natural reinforcements in composites, it focuses on wood as a fundamental representative of lignocellulosic fibers. It elucidates the concept of wood flour, the criteria for its selection, methods of storage, morphological characteristics, and similar aspects. The presence of wood in the plastic matrix reduces the material cost while increasing the stiffness. Matrix selection is influenced by the processing temperature (Tmax = 200 °C) due to the susceptibility of cellulose fibers to thermal degradation. Thermoplastics and selected biodegradable polymers can be applied as matrices. The article also includes information on applied additives such as coupling agents, lubricants, biocides, UV stabilizers, pigments, etc., and the mechanical/utility properties of WPC materials. The most common application of WPCs is in automotive sector, construction, aerospace, and structural applications. The potential biodegradability and lower cost of applications featuring composite materials with natural reinforcements motivated us to delve into this type of work. [ABSTRACT FROM AUTHOR]

Commercial products made of plastics or wood have always been in high demand until now. Consequently, waste from these products has increased, accumulated, and catastrophically impacted the environment. Through recycling, waste products are not only reduced but will also be easily available for improvement or manufacturing new products. This research focused on the fabrication of lightweight composites using plastic waste (PW) and wood waste (WW) as reinforcement and epoxy as a matrix suitable for tile applications. It was revealed that the density of PW-WW polymer composite increased with increasing PW loading up to a 4.0 ratio at 1.070 g/cm³ with a porosity of 0.05%. Optical microscope analysis at 100X magnification showed good bonding between the reinforcements (PW and WW) and matrix (epoxy). With a maximum bending strain of 2.41%, the 3.0 ratio achieved the highest bending strength of 2069.20 N, followed by the bending stress at 8.28 MPa. The PW-WW polymer composite with a composition ratio of 3.0 showed a maximum tensile force of 313.8 N and a tensile strength of 1.79 MPa. The composite with a 4.0 ratio had the greatest impact strength (1.67 kJ/m²), followed by the composite with a 3.0 ratio (1.44 kJ/m²). In summary, a 3.0 ratio is the best polymer composite composition for tile applications. [ABSTRACT FROM AUTHOR]

The unique properties and sustainability advantages of sulfur polymer cement have led to efforts to use them as alternatives to traditional Portland cement. The current study explores the impact of environmental stresses on the strength development of polymer composite SunBG90, a material composed of animal and plant fats/oils vulcanized with 90 wt. % sulfur. The environmental stresses investigated include low temperature (−25 °C), high temperature (40 °C), and submersion in water, hexanes, or aqueous solutions containing strong electrolyte, strong acid, or strong base. Samples were analyzed for the extent to which exposure to these stresses influenced the thermo-morphological properties and the compressional strength of the materials compared to identical materials allowed to develop strength at room temperature. Differential scanning calorimetry (DSC) analysis revealed distinct thermos-morphological transitions in stressed samples and the notable formation of metastable γ-sulfur in hexane-exposed specimens. Powder X-ray diffraction confirmed that the crystalline domains identified by DSC were primarily γ-sulfur, with ~5% contribution of γ-sulfur in hexane-exposed samples. Compressive strength testing revealed high strength retention other than aging at elevated temperatures, which led to ~50% loss of strength. These findings reveal influences on the strength development of SunBG90, lending important insight into possible use as an alternative to OPC. [ABSTRACT FROM AUTHOR]

Hybrid composites are an advanced solution that offers multifunctional capabilities, including exceptional strength-to-weight ratios, vibrational damping and impact absorption. This work describes the damping capacity and flexural behaviour of a hybrid fibrous-particulate system composed of glass/carbon fabrics and three distinct micro-inclusions: silica particles, carbon waste microfibres, and cement. A statistical methodology based on the full factorial design is applied to identify the effects of fibre stacking sequence, including carbon-C5, glass-G5, C2G3, G3C2, GCGCG and CG3C, microparticle inclusions and matrix/fibre volume fraction (40/60 and 60/40) on damping and bending responses. A non-linear finite element (FE) analysis is conducted to explore the stress distribution based on the stacking sequence and predict the failure mechanisms of the hybrid laminate. The results indicate significant interaction effects, with hybrid architectures showcasing approximately 33% higher performance compared to glass fibre composites. A greater dependence on the fibre layup sequence is found for the damping factor, flexural modulus and strength. Notably, the incorporation of silica microparticles leads to an increase in flexural strength. Furthermore, a greater volume fraction of the matrix phase enhances the rheological efficiency in terms of the fibre-particle interface. Carbon fibre layers placed symmetrically on both beam sides (CG3C) and bottom layers (G3C2) significantly enhance the bending performance of hybrid composites. [ABSTRACT FROM AUTHOR]

This paper investigates the durability of geopolymers and geopolymeric mortars made with metakaolin and alkaline activators, with and without a coconut fiber addition, after immersion for seven days into solutions of citric acid (1%, 2.5%, 5%, and 10%); hydrochloric acid (1%, 2.5%, 5%, and 10%); and sulfuric acid (1%, 2.5%, 5%, and 10%). The study focuses on mass changes, uniaxial compressive strength, flexural strength, and ultrasound pulse velocity measurements. X-ray diffraction and scanning electron microscopy are used to analyze the degradation products and microstructural changes. The aim is to assess the effect of acid exposure on the strength and stability of geopolymer materials and identify any protective effects of coconut fiber reinforcement. The samples are immersed in acid solutions of varying concentrations, and their mechanical properties are measured. The presence of coconut fibers slightly modifies the physical properties and the compressive strength, improving the mechanical flexural strength. Geopolymer and geopolymeric mortar materials experienced a weak decrease in strength when exposed to solutions of citric acid and a significant one when exposed to solutions of hydrochloric and sulfuric acids, attributed to depolymerization of the aluminosilicate binders. Brick waste geopolymeric mortars reinforced with coconut fibers showed the best performance in acid solutions with respect to geopolymers and quartz-rich sand geopolymeric mortars, suggesting a more stable cross-linked aluminosilicate geopolymer structure in this material. [ABSTRACT FROM AUTHOR]

To make full use of plant shell fibers (rice husk, walnut shell, chestnut shell), three kinds of wood-plastic composites of plant shell fibers and polyvinyl chloride (PVC) were prepared. X-ray diffraction analysis was carried out on three kinds of plant shell fibers to test their crystallinity. The aging process of the composites was conducted under 2 different conditions. One was artificial seawater immersion and xenon lamp irradiation, and the other one was deionized water spray and xenon lamp irradiation. The mechanical properties (tensile strength, flexural strength, impact strength), changes in color, water absorption, Fourier transform infrared spectroscopy (FTIR), and microstructures of the composites before and after the two aging experiments were analyzed. The results showed that the chestnut shell had the highest crystallinity, which was 42%. The chestnut shell/PVC composites had the strongest interface bonding, the least internal defects, and the best general mechanical properties among the three composites. Its tensile strength, bending strength and impact strength were 23.81 MPa, 34.12 MPa, and 4.32 KJ·m, respectively. Comparing the two aging conditions, artificial seawater immersion and xenon lamp irradiation destroyed the quality of the combination of plant shell fibers and PVC, making the internal defects of the composites increase. This made the water absorption ability and changes in the color of the composites more obvious and led to a great decrease in the mechanical properties. The general mechanical properties of the chestnut shell/PVC composites were the best, but their water absorption ability changed more obviously. [ABSTRACT FROM AUTHOR]

Lignocellulosic-based polymer composites have gained significant interest due to their ''green" character as a response to environmental concerns. A diverse array of lignocellulosic fibers is utilized, depending on fiber dimensions, chemical composition, moisture content, and the fiber–matrix interface. The aim of this study is to establish an alternative standardized methodology, aimed at comparatively estimating the performance of polymer composites through the examination of individual plant fibers. The fibers studied are ramie, hemp, flax, and kenaf, and HDPE-based corresponding composites were analyzed for their performance across various fiber-content levels (10, 20, and 30 wt.%). It was found that kenaf showcases the largest average fiber diameter, succeeded by hemp, ramie, and flax. Additionally, ramie and kenaf exhibit elevated levels of crystallinity, suggesting increased cellulose content, with kenaf having the lowest crystallinity index among the fibers compared. Based on Thermogravimetric analysis, ramie displays the lowest moisture content among the examined fibers, followed by hemp, flax, and ultimately kenaf, which is recorded to have the highest moisture content, while, similarly, ramie exhibits the lowest mass loss at the processing temperature of the corresponding composites. Composites containing fibers with smaller diameters and higher crystallinity indexes and lower moisture absorptions, such as ramie and hemp, demonstrate superior thermal stability and exhibit increased Young's modulus values in their respective composites. However, poor interfacial adhesion affects mechanical performance across all composites. Understanding fiber morphology, inner structure, and thermal stability is important for developing new composite materials and optimizing their selection for various applications. [ABSTRACT FROM AUTHOR]

In the present work, a combination of virgin polypropylene and E-glass fiber was subjected to ten (10) reprocessing cycles via extrusion and compression molding techniques to mimic recycling and its impacts on the bending properties of the composites. The samples were characterized using Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM), and melt flow index (MFI). The results revealed a gradual depreciation in flexural properties after each reprocessing cycle. The XRD analysis indicated a substantial reduction of peak intensities, degrees of crystallinities, and average crystallite sizes, explaining the lowered flexural properties in addition to a possible reduction in glass fiber lengths (fiber attrition). Melt-processing behavior shows a progressive increase of MFI from 7 to 19.16 g/10 min, confirming the probable damage in molecular weight and loss of complex viscosity. Chemical and structural analysis showed no alteration in the polypropylene major functional groups. It is concluded that the reductions in molecular weight and composites' properties occurred due to chain scission from recycling effects; hence, glass fiber-reinforced polypropylene composites can be recycled only three (3) times unless it is refreshed by the addition of virgin parts to compensate for the lost property. [ABSTRACT FROM AUTHOR]

This study investigates the mechanical properties of coconut sawdust powder combined with polypropylene (PP). The effect of compatibility content, wood powder (WP) content, and injection molding parameters on the properties of coconut wood powder composite (WPC) is evaluated. The results could be used to figure out the optimal mechanical properties such as tensile strength, elongation, elastic modulus, and flexural strength by selecting suitable parameters and composition. The bonding between the WP particles and the PP matrix is good, and the WP is uniformly distributed across the composite matrix, as indicated in the scanning electron microscopy (SEM) results. Interestingly, with the presence of the compatibilizer oleamide, increasing the WP content from 20 wt.% to 40 wt.% did not result in WP accumulation in the composite matrix. Notably, at 20 wt.% WP, the elongation is the highest (at 7.40 wt.%), while at 30 wt.% WP, the elastic modulus reaches the highest value. The maximum ultimate tensile strength (UTS) value is obtained at 35 wt.% WP. Higher WP mostly results in greater flexural strength and shore D hardness. At 40 wt.% WP, the WPC achieves its peak shore D hardness of 77.6. The Taguchi results suggest that WP content is the most critical factor in the UTS value of coconut WPCs. The filling pressure ranks second, followed by the packing pressure. Finally, unlike the other characteristics, the melt temperature has a minimal impact on the UTS value. [ABSTRACT FROM AUTHOR]

Wood is a primary building tool for ancient buildings and structures, but for those that survive to date, naturally aged wood may pose a noteworthy fire hazard. There are potential risks to health, safety, and substantial cultural loss if fire risks in such buildings are not mitigated. We obtained several samples of aged wood commonly used in ancient structures (elm, pine, and aspen), and compared the kinetic and thermal characteristics to fresh wood examples to determine potential methods of enhancing safety. Differential scanning calorimetry was used to establish the heat release characteristics of the fresh and aged samples, and the characteristics of the thermal reaction stages were characterized using the temperature range and heat release laws for each reaction stage. The heat release characteristics during combustion were investigated for different heating rates, and the influence of aging on temperature change and heat release rate characteristics during different exothermic stages was assessed. Finally, using heat flow data, the apparent activation energy (AAE) of the samples and their distributions during different exothermic stages were calculated and analyzed via the Friedman differential iso-conversion method. Results showed that the exothermic energy of the aged samples was higher than that of the fresh samples, indicating that aging does impact the thermal reaction process. The aged samples in this study had a greater heat diffusion capacity, transmitted more heat, were more susceptible to burning (by spreading that heat), and generally posed a greater fire hazard. During the rapid exothermic phase, the AAE of aged wood increased as the reaction progressed, and exhibited lower AAE with a greater sensitivity to fire than fresh samples. A sound linear relationship between pre-exponential factor and AAE and the kinetic compensation effect was obvious. This study provided a rudimentary theoretical basis for the prevention of fires in timber-framed ancient buildings. [ABSTRACT FROM AUTHOR]

Recent earthquakes and escalating energy demands are exposing building stock deficiencies, particularly in terms of seismic resilience and energy efficiency. Many aged constructions do not fulfil current regulations both in terms of seismic and thermal design principles, thus requiring suitable retrofitting solutions. Integrated approaches for concurrent seismic and energy renovation have emerged as promising strategies in recent years, offering holistic solutions that optimize interventions and maximize benefits. While these combined methods hold significant potential for practical applications, there remain opportunities for further research to enhance their advantages. Furthermore, addressing climate concerns requires concentrated effort within the construction sector, where synergetic refurbishments can serve a dual purpose by reducing emissions and promoting the use of more sustainable materials. This study discusses strategies proposed in the literature for integrated retrofitting, considering their environmental impact, both in terms of energy performance and embodied carbon. The overview shows the innovation potential for the development of materials and systems combining acceptable performance with eco-friendly attributes. Yet, their application in integrated retrofitting systems, either as structural components or insulators, is still limited, underscoring the need for continued investigation and advancement. This paper concludes with recommendations to inspire further research and advancements in this critical field. [ABSTRACT FROM AUTHOR]

Four dimensional printing enables the advanced manufacturing of smart objects that can morph and adapt shape over time in response to stimuli such as heat. This study presents a single-material 4D printing workflow which explores the residual stress and anisotropy arising from the fused deposition modelling (FDM) printing process to create heat-triggered self-morphing objects. In particular, the study first investigates the effect of printing patterns on the residual stress of FDM-printed acrylonitrile butadiene styrene (ABS) products. Through finite element analysis, the raster angle of printing patterns was identified as the key parameter influencing the distribution of residual stresses. Experimental investigations further reveal that the non-uniform distribution of residual stress results in the anisotropic thermal deformation of printed materials. Thus, through the design of printing patterns, FDM-printed materials can be programmed with desired built-in residual stresses and anisotropic behaviours for initiating and controlling the transformation of 4D-printed objects. Using the proposed approach, any desktop FDM printers can be turned into 4D printers to create smart objects that can self-morph into target geometries. A series of 4D printing prototypes manufactured from conventional ABS 3D printing feedstock are tested to illustrate the use and reliability of this new workflow. Additionally, the custom-made wood–plastic composite (WPC) feedstocks are explored in this study to demonstrate the transposability of the 4D printing approach. [ABSTRACT FROM AUTHOR]

Styrene–butadiene rubber (SBR) composites reinforced with two different local Libyan grasses; Stipa tenacissima (locally known as Halfa) and Stipagrostis pungens (locally known as Esbat); were prepared. The effect of filler type and content (10, 20, 30 and 40 wt%) on the mechanical properties of the composites including stress at break, elongation at break, impact strength and microhardness were evaluated. The results illustrated that the stress at break of SBR increased with the addition of 20% and 30% of Halfa or Esbat. In addition, the results revealed that the highest values of stress at break were obtained by composites with 20% filler content. Composites made with Halfa showed higher stress at break than composites made with Esbat. The incorporation of Halfa and Esbat into SBR caused a significant decrease in the elongation at break. The elongation at break of the composites made with Halfa was slightly higher than that of composites made with Esbat. In both types of composites, the impact strength was increased with increasing the filler content up to 30%, and then decreased. Composites made with Esbat showed marginally better impact strength than did composites made with Halfa. The incorporation of Halfa and Esbat caused an increase in the hardness properties in comparison to pure SBR. In the all composite compositions, Halfa composites had higher hardness values than Esbat composites. The optical microscope results of SBR composites were in good agreement with the mechanical properties results. The formation of filler aggregation was observed in SBR composites with 10% and 40% Halfa and Esbat. On the other hand, no filler aggregation was observed in the optical images of SBR composites with 20% and 30% Halfa and Esbat. In brief, these grasses can be used as effective filler for reinforcing polymers to develop low density composites with improved properties. [ABSTRACT FROM AUTHOR]

Modular construction is becoming famous for buildings because it allows a high degree of prefabrication, with individual modules easily transported and installed. Building envelope optimization is vital as it protects buildings from undesirable external environments by expressly preventing the incursion of outside elements. This research uses a systematic literature review to appraise the characteristics of modular envelope panels, focusing on hygrothermal and energy performance. A total of 265 articles were subjected to rigorous filtering and screening measures. The findings reveal notable inconsistencies in modular envelope terminologies and a lack of consistent performance measures, which present significant challenges for research and development efforts. Furthermore, the results indicate a predominant focus on hygrothermal and energy performance in existing studies, with limited attention to environmental impacts and other performance factors. Moreover, the existing literature primarily addresses modular envelope solutions in temperate climates, offering inadequate information for hot and hot–humid climate contexts. To address these gaps, this study proposes categorizing modular envelope panels into four distinct categories: active, passive, smart, and green/vegetated wall panels. These findings will benefit researchers, architects, building envelope designers, policymakers, and organizations developing building performance-related assessment ratings, standards, and codes. The study suggests adopting the categorization of modular envelope panels provided in this study and developing modular panels suitable for hot and humid climates to fill the existing knowledge gap. [ABSTRACT FROM AUTHOR]

Considering recent climate changes, special importance is given to any attempt to depollute and protect the environment. A circular economy seems to be the ideal solution for the valorization of mineral waste, resulting from various industrial branches, by reintroducing them in the process of obtaining alternative building materials, more friendly to the environment. Geopolymers can be considered as a promising option compared to Portland cement. Information about the influence of the composition of the precursors, the influence of the activation system on the mechanical properties or the setting time could lead to the anticipation of new formulations of geopolymers or to the improvement of some of their properties. Reinforcement components, different polymers and expansion agents can positively or negatively influence the properties of geopolymers in the short or long term. [ABSTRACT FROM AUTHOR]

Nanocrystalline cellulose (NCC) from natural Agave sisalana (Sisal) fibers were isolated using a combination of chemical and mechanical processes. The chemical treatment begins with soaking the fiber in a sodium hydroxide (NaOH) solution with a concentration of 5 wt.% at a temperature of 90°C for 60 minutes. Then following by bleaching (fiber refining) using a hydrogen peroxide solution (H2O2) with a concentration of 3 wt.% (weight), at a temperature of 60°C, and pH of 10 for 30 minutes. It aims to eliminate the presence of hemicellulose and lignin contained in the fiber. Fibrillation Micro into nano Sisal fibers using sulfuric acid (hydrolysis process). Sulfuric acid (H2SO4) with 55 wt.% at temperature 60°C for 30 minutes produced NCC with a diameter of 5±1 nm (D) and a length of 260±10 nm (L), as seen using a TEM (transmission electron microscope). The web-like network structured shape of NCC results in a high aspect ratio (L/D) value is 52. The acid hydrolysis-ultrasonication process produced a high crystallinity index of 78.82% through the XRD (x-ray diffraction) test. The crystallinity and aspect ratio of NCC show that Sisal fiber is a suitable material as a filler for bio-nanocomposite materials. The maximum temperature (Tmax) of NCC decreased by 10°C due to sulfate ions attached to the cellulose structure, causing the thermal stability to drop from 348°C to 338°C. [ABSTRACT FROM AUTHOR]

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The aim of this work was to characterize the thermal properties of wood prior to pyrolysis. The Anisotropic Parallel Hot Wire (APHW) technique was applied to characterize 8 wood species with densities varying between 100 and 1000 kg m−3. This variant of the hot wire technique allows the simultaneous measurement of the transverse and longitudinal thermal conductivity and the volumetric heat capacity of wood. Measurements were performed at 4 different temperatures: 20, 60, 110 and 160 °C. The results show that the thermal conductivity in both directions is independent of the type of wood (hardwood or softwood) and it increases linearly with density. Furthermore, the measurements show that the transverse thermal conductivity increases with temperature in contrast to the longitudinal conductivity which is either independent or decreases slightly with the temperature. Therefore, the anisotropy factor decreases with the temperature. The effect of water was also studied by characterizing the same samples at 20 and 60 °C, wet (water content ≈ 10%) and dried. The latter results show that thermal conductivity increases with the moisture content. Meanwhile, the effect of water is larger in the transverse direction. The heat capacity was also measured by the Differential Scanning Calorimetry (DSC) technique between 20 and 90 °C every 10 °C. The latter measurements show that the heat capacity is independent of the density and the wood species. It increases linearly with temperature for all wood species. [ABSTRACT FROM AUTHOR]

The shrinkage characteristic of porous materials is an important consideration in the drying process, as it can significantly impact the texture of the dried product and energy utilization. This phenomenon is influenced by numerous factors, including the structure of the cells, drying conditions, and the glass transition temperature. To gain a deeper understanding of the drying process, it is necessary to develop theoretical models that account for the simultaneous heat and mass transfer processes at the cellular level, as well as simulation tools to analyze the associated changes in drying morphology. In this paper, we highlight several key factors affecting shrinkage during the drying of porous materials, and also outline drying modeling, morphological simulation, and drying technology design considerations to provide guidance for improving the drying quality of porous materials as well as energy conversion efficiency. [ABSTRACT FROM AUTHOR]

Obtaining bulk copper-based composite materials with improved physical and mechanical properties often requires pre-treatment of the initial raw materials. Especially it concerns metal matrix composites (MMC) containing copper as a matrix and silicon carbide as a reinforcing component. However, the final properties of Cu/SiC MMC depend on successful solving the problem of silicon solubility in liquid-phase copper during the sintering process. In this work, we demonstrate the possibility of high-energy treatment of copper and silicon carbide by the plasma dynamic method to obtain a pre-activated charge for further sintering. Analytical studies by X-ray diffractomtery (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods testify to the possibility of obtaining highly dispersed composite Cu/SiC materials of different phase and grain size composition depending on the synthesis conditions. The application of polymodal Cu/SiC powders pre-activated by the plasma dynamic method as a charge is established to ensure producing bulk samples by the spark plasma sintering (SPS) method and allow increasing the relative density by ~ 5%–10% and the hardness of the final products by more than 30% compared with pure copper samples produced by the same method. [ABSTRACT FROM AUTHOR]

This work aims to use experimental data from thermal characterization and adsorption/desorption isotherms of two tropicals woods species (Ayous and Tali) to propose an empirical model of thermal conductivity as a function of air relative humidity. A static gravimetric method was used to determine the adsorption isotherms of Tali and Ayous at 30 °C, and 40 °C. The GAB, Henderson and Nelson models were used to predict the isotherms. Exponential models of thermal conductivity and volumetric heat capacity with air relative humidity were proposed. The influence of hysteresis phenomenum was studied on these properties. The reliability of the developed empirical correlation between thermal properties and air relative humidity was evaluated by comparing the experimental and predicted curves. The relative errors were less than 8% for both Ayous and Tali. The correlation coefficients obtained were greater than 99% for both species in adsorption and desorption. There was also an increase in the equilibrium water content of both species with the increase in water activity at constant temperature. The correlation coefficients between GAB model and sorption experimental data were lower than 99% when Ayous was subjected to a temperature of 40 °C in adsorption and Tali to a temperature of 40 °C in desorption. [ABSTRACT FROM AUTHOR]

To investigate the mechanism of reinforcing soft soil with cement-mixing pile, based on ABAQUS secondary development, a numerical simulation study of the hydration reaction of cement-mixing piles was conducted. In this study, the influence of ground temperature variations on the distribution patterns of the temperature field in and around the pile was also considered. The temperature field of the pile–soil model can be primarily divided into two stages: the temperature rise stage (0~5 d) and the temperature decrease stage (5~90 d). The following observations were made: (1) The temperature of the pile body rapidly increased within the first 5 days, dissipating heat to the surrounding soil, leading to an elevation of the temperature in the soil around the pile and a decrease in soil moisture content. Around the 5th day, the temperature reached its maximum value, and the heat release rate of the pile body was higher than that of the surrounding soil. (2) With a 15% cement admixture, under the influence of 425# cement hydration, the temperature inside the pile increased by 5 °C, and the temperature in the soil around the pile increased by 4.2 °C. After considering the ground temperature, the temperature in the soil around the pile increased by 4.6 °C. (3) The maximum temperature generated during the hydration of 425# Portland cement is higher than that of 525#; the temperature of the soil around piles made with 425# cement is consistently higher than that made with 525#. (4) The hydration temperature of piles with a 10% cement admixture increased by 4.4 °C; for piles with a 15% cement admixture, the hydration temperature increased by 6.6 °C; and for piles with a 20% cement admixture, the hydration temperature increased by 9.1 °C. The temperature field of this structure gradually stabilizes after 7 days with increasing time and cement admixture. The results indicate that the hydration of cement-mixing piles raises the temperature of the soil around the piles. Additionally, the temperature resulting from the hydration of cement-mixing pile increases with the addition of cement. [ABSTRACT FROM AUTHOR]

This paper tackles the issue of moisture variation in wood-based materials, explicitly focusing on melamine-coated particleboard (hereafter referred to as melamine) and medium-density fiberboard (MDF) used in the third phase of wood industry transformation. The approach involves a comprehensive strategy for predicting moisture content variation, incorporating numerical simulation, experimental testing, and the application of artificial neural network (ANN) technology to enhance accuracy in furniture manufacturing. The developed ANN models are tailored to predict moisture content changes under specific thermal comfort conditions. Remarkably, these models demonstrate high precision, with an average error margin of only 1.40% for 8% moisture content (MC) and 2.85% for 12% MC in melamine, as well as 1.42% for 8% MC and 2.25% for 12% MC in MDF. These levels of precision surpass traditional models, emphasizing this study's novelty and practical relevance to the industrial context. The findings indicate that ANN models adapt to diverse environmental conditions, presenting a robust tool for optimizing moisture management in wood-based materials. This research contributes valuable insights for improving the reliability and efficiency of moisture content predictions in the wood industry. [ABSTRACT FROM AUTHOR]

Plastic contamination is commonly reported in urban and rural soils, as well as in fresh and ocean waters. Canada's government has attempted to limit the contamination of single-use plastic by banning the manufacturing and selling of specific types of plastic. In British Columbia, current regulations governing commercial composting state that when compost has less than 1% of its dry weight representing foreign materials (including plastic), it can be sold and used in soils. However, due to the low density of plastic and its potential to break down into microparticles, this amount may be enough to become toxic when used in agricultural soils. This paper studies contamination of plastic in garden soils and summarizes how this can affect the environment with a preliminary examination of a garden soil sample. The examination showed that the garden soil sample contained mainly low-density polyethylene, polyethylene and polypropylene plastics (identified through ATR-FTIR) in oxidized and unoxidized forms that can come from commercial composting and hypothesizes that this plastic could break down into microplastic particles. In order to limit the amount of plastic contamination in agricultural soils, it is necessary to modify current compost regulations in order to treat plastic differently than other foreign materials (glass, metal, wood). [ABSTRACT FROM AUTHOR]

The study uses densified sawdust with heat propagation and thermal conductivity to achieve better pyrolysis and gasification processes. Analysis of sawdust's heat propagation and thermal conductivity during pyrolysis was developed with Finite Element Analysis (FEA). The thermal conductivity values of sawdust (k) obtained from FEA are 1.49, 1.3, 1.1, and 0.7 W/m C considering the sawdust heated with a triggering temperature (T0) 535 ℃ and reaches a constant temperature of T1 = 265 ℃, T2 = 165 ℃, T3 = 115, and T4 = 95 ℃ respectively after 20 minutes. The temperature distribution of sawdust heated shows between the experimental and FEA results is quite the same; however, differences on graph T1 show the experimental thermal conductivity (k) value is distinct from the simulated thermal conductivity (k) value due to a significant change that occurred as sawdust transformed into charcoal at minute 70, where the distance between point T1 and the trigger point (T0) is 40mm and after 180 minutes the sawdust had turned into charcoal completely. Furthermore, 31 grams (6.46%) of sawdust underwent pyrolysis in this experiment. The findings can aid future research and development in this field and provide valuable insight into the duration of time a bio stove utilizing compacted sawdust can produce a sustainable flame and be used as a reference for future experiments. [ABSTRACT FROM AUTHOR]

The current goal of the European Commission, which aims to reduce CO2 by 90% compared to values estimated in 1980, and the ever-increasing sensitivity to environmental sustainability, fully involve the construction sector, which, according to the OECD (Organization for Economic Co-Operation and Development) is responsible for over one-third of the world's energy requirement. In this frame, numerous researchers and companies are focusing on ecologically sustainable building materials, to be used in new and existing buildings, that are able to simultaneously fulfill the constructive function and improve the energy behavior of the building envelope. The goal of the present paper is the analysis of the energy performance of some innovative locally produced natural building materials (timber, sheep wool, rammed earth, lime-based plaster, natural fibers) used in multilayer vertical closures, compared to that of more common building materials (bricks, concrete, synthetic insulation). First, the physical-mechanical characterization of the local natural materials was carried out, then the model of a building was implemented, whose energetic performance was simulated by varying the type of stratigraphy of the walls, including the use of both innovative and common materials. The building chosen for the simulation consists of one of the BESTEST ANSI/ASHRAE reported in the 140-2017 standard using the climatic data of the Mediterranean area. The results of the simulation have been presented and discussed. [ABSTRACT FROM AUTHOR]

Due to their durability, versatility, and aesthetic value, wood and wood-based composites are widely used as building materials. The fact that these materials are flammable, however, raises a major worry since they might cause fire hazards and significant loss of life and property. The article investigates the variables that affect fire performance as well as the various fire-retardant treatments and their mechanisms. The current developments and challenges in improving the fire performance of wood and wood-based composites treated with fire-retardant materials are summarized in this paper. Nanoparticles, organic chemicals, and densification are some recent developments in fire-retardant treatments that are also emphasized. Key points from the review are summarized, along with potential areas for further research and development. [ABSTRACT FROM AUTHOR]

Wood–plastic composites (WPC) are partially biobased composite materials that exhibit appealing properties, but also some drawbacks. One is the inherent propensity to take up water, which influences different composite properties. In this work, we investigated the general water uptake behavior of injection-molded WPC and applied a simple model to evaluate different formulations. We found that the major influence is the wood content, but also, wood particle size showed a distinct influence on the water uptake speed, while the saturation concentration correlated with the equilibrium moisture content of the wood. The mechanical properties, such as elastic modulus and tensile strength, were reduced with increasing water uptake, and the reduction correlated with wood content and the moisture content of the wood, while the particle size did not show an influence in the investigated region. [ABSTRACT FROM AUTHOR]

The present study is focused on wall panels exposed to fire, with the construction building elements we used being made of wood and gypsum board materials. This type of configuration forms hollow core wood due to the constructive process. The aim is to present a numerical study to approach the calculation of the temperature inside hollow core wood elements and measure their fire resistance. The temperature evolution inside the cavities will be obtained with recourses to obtain the heat effect by convection and radiation through the wall elements. A numerical model, previously validated by the authors, will be used to carry out this process. The methodology includes the use of the finite element method in thermal and transient analysis with nonlinear materials to calculate temperature. To measure the fire resistance of the constructive model, the thermal insulation criterion, defined by the EN 1363-1:2020 standard, will be applied. Different results will be presented to discuss and ensure the verification of these fire-resistant elements. [ABSTRACT FROM AUTHOR]