Water Absorption Measurements Research Articles

Evaluation of Clayey Raw Materials and Ceramic Masses from Ceramic Building Material Companies Located in Northeastern Brazil

The challenge of improving the quality of ceramic products is faced worldwide, especially in areas where artisanal production is common and the need for in-depth knowledge about raw materials, together with inefficient production processes, limits the advancement of the ceramic industry. Scientifically, detailed investigation of ceramic masses’ physical, chemical and mechanical properties can provide essential insights to optimize production, contribute to developing more advanced and sustainable techniques, and increase competitiveness. This study evaluated raw clay materials and ceramic masses obtained from northeastern Brazilian, focusing on their chemical composition, mineralogical phases, thermal behavior, and particle size distribution. Rectangular samples (80 mm × 20 mm × 7 mm) prepared using uniaxial pressing (25 MPa by 30 s) were fired at different temperatures (950 and 1050 °C) and linear shrinkage, flexural strength, water absorption, and apparent porosity measurements were taken. The results showed that the companies still need to improve the production process to meet the minimum strength requirement of 1.5 MPa according to the Brazilian standard NBR 15270.

Biochar-enabled carbon negative aggregate designed by core-shell structure: A novel biochar utilizing method in concrete

Using carbon-negative biochar is promising for the carbon footprints reduction of construction materials; however, directly utilizing biochar in concrete would negatively influence its mechanical properties, particularly when the utilizing volume exceeds a certain threshold. By designing as a core-shell structure through cold-bonding method, a novel carbon-negative core-shell aggregate (CSA) with a biochar core and a cementitious shell was developed in this study. The aggregate was characterized by strength, density, and water absorption measurements, meanwhile, analyzed by hydration heat, XRD, TGA, SEM/BSE, and X-CT. The results showed that the developed MG80 biochar-CSA attained a loose bulk density of 789 kg/m3. It exhibited a crushing strength of 6.84 MPa, a water absorption value of 19.4 %, and a significantly superior strength efficiency of 8669 Pa·m3/kg compared to commercially sintered artificial lightweight aggregates and other cold-bonded aggregates documented in literature. The carbon emission assessment indicated that producing one ton of MG80 biochar-CSA emitted −69 kg CO2, which was much lower than the commercial sintered aggregates. Concrete developed by replacing natural aggregate with 90 % MG80 biochar-CSA exhibited a compressive strength of 42.2 MPa while maintaining lightweight with density of 1866 kg/m3, which conforms to the standard-classified structural lightweight aggregate concrete.

Feasibility of foam concrete using recycled brick and roof tile fine aggregates

Brick (BR) and roof tile (RT) fine aggregate fractions derived from construction and demolition wastes have a low recycling rate in new construction and building materials. This article assesses their suitability for replacing the limestone aggregate in foam concrete, which helps valorise such fractions and conserve natural limestone resources. Two concrete categories containing or not silica fume (SF) were investigated, while the BR and RT aggregate replacement rates were 10%, 20% and 40%. Tested properties include flow, density, water absorption, porosity, thermal conductivity, mechanical strengths, microscopy, drying shrinkage, resistance to freeze/thaw cycles and elevated temperature. Results showed that the concrete mechanical properties improved when the limestone aggregate was replaced by 10% BR or RT but gradually curtailed at higher addition rates. Such results concorded with the density, water absorption and porosity measurements. Foamed concrete containing BR is more resistant (compared to RT) to drying shrinkage, freeze/thaw cycle, and heat exposure, which was ascribed to the relatively lower BR porosity that improves the concrete mechanical properties and durability.

Proportioning Study for Low-carbon Sulfate-resistant Concrete by Microbial Corrosion Testing

In addition to water absorption and chloride permeability measurement, sulfate resistance testing by microbial corrosion was conducted on low-W/B concretes made using large amounts of supplementary cementitious materials, including GGBF slag, for use as sewage pipes. The corrosion testing was conducted in a corrosion chamber at 30°C with a H2S concentration of 100 ppm, in which specimens were exposed to the environment under two conditions: one group in the gas and the other partially submerged in circulating sewage water. After exposure for one year, the corrosion rate in the partially submerged phase tended to be 1.3 to 2.9 times higher than in the gas phase. Also, the amount of corrosion was compared, with the corrosion products being examined by EPMA. Exposure to the gas phase and partially submerged phase was thus found to represent the stage of forming monosulfates and dihydrate gypsum and ettringite, respectively. Deterioration was found to proceed at a higher rate as the pH value on the concrete surfaces decreased. Within the range of this study, the addition of silica fume and small-size GGBF slag led to no appreciable effect.

Study on the Water Absorption Characteristics of Anthracite Particles after Immersion in Water.

Reducing pollution caused by coal dust has always been a hot issue in the coal mining industry, and the water absorption of coal particles plays an important role in dust reduction. To study the relationship between different immersion time and the water absorption of coal particles, the substance content of coal particles after immersion was analyzed and water absorption characterization of coal particles was carried out by X-ray diffraction (XRD), water absorption calculations, and water absorption measurements. The results indicate that immersion can alter the material content of coal particles, leading to a decrease in the content of soluble mineral kaolinite, thereby affecting the wettability of coal particles. Notably, the longer the immersion time, the higher the water absorption rate of the particles, indicating a more significant water absorption effect. Furthermore, there is a negative correlation between particle sizes and water absorption of coal particles. The research results provide a theoretical reference for reducing coal dust pollution and improving the efficiency of dust suppression through spray.

Flame retardancy of cotton and cotton/polyester fabrics treated by coating with polymer blends containing aluminum and phosphorus metals under the effect of gamma irradiation

The main objective is to impart flame retardancy finishing to cotton and cotton/polyester fabrics. In this process, the fabrics were first treated by coating with poly(vinyl alcohol) (PVA)/plasticized starch (PLST) blends and then exposed to gamma irradiation. The treated fabrics were then loaded with aluminum sulphate [Al2(SO4)3] and monosodium dihydrophosphate (MSDP). The treated fabrics were characterized by the measurements of water absorption, crease recovery, surface morphology and tensile mechanical. Moreover, thermal stability of the treated fabrics was investigated by thermogravimetric analysis (TGA). The thermal stability was further investigated by determining the activation energy by two different methods based on Broido and the Horowitz–Metzger approximation equations. The results showed that the chemical and physical properties of the treated fabrics with PVA/PLST/metal composites were significantly improved. The flammability test in terms of time to catch fire (TF), time after glowing (TG) and weight left (WL) showed that the treated fabric and loaded with [Al2(SO4)3] and MSDP metals displayed improved flammability than untreated fabrics. In addition, the durability of the flame retardancy finished fabrics was evaluated by measuring the limiting oxygen index (LOI) after repeated washing cycles according a standard testing method. The results of durability test indicated that the fabrics treated with composites based on both [Al2(SO4)3] or MSDP metals proved to satisfy the flame retardancy with minimum weight lose percent.

Exploring the potential of nitrophosphogypsum and calcined water-treatment plant sludges in mortar mixtures: A study on workability and strength

Mortar mixtures that consider alternative mineral admixtures are of constant research interest to reduce ordinary Portland cement (OPC) content thereby lowering final cost and carbon footprint. An additional concern is the proper management of industrial process residues that could be used in mortar mixes to avoid their disposal in landfills or water bodies. This work investigated the potential of using calcined water treatment plant sludge (CWTPS) and nitrophosphogypsum (NPG) - a byproduct of the fertilizer industry - as partial replacements of OPC in mortar mixtures. For this purpose, this research evaluates the crystallographic, chemical, and physical properties of NPG and CWTPS through X-ray diffraction (XRD), X-ray fluorescence (XRF), and Scanning Electron Microscope (SEM). XRF and XRD findings strongly suggests that CWTPS qualifies as supplementary cementitious materials, due to its high content of silicon and aluminum oxides in a non-crystalline state. On the other hand, NPG could be used as a mineral admixture. The design of mixtures was based on the workability of 85% flow. The evaluation of properties encompasses the measurement of density, compressive strength, durability (pH and sulfate environments), and water absorption. The results demonstrate that incorporating of NPG and CWTPS to mortar mixes, each at a 5% inclusion rate (with a total replacement of 10% of OPC), increase compressive strength by up to 6.65% at 90 days compared to the control group in mortar mixes. However, the inclusion of NPG and CWTPS significantly decreases the workability of mortar mixes by up to 51.49%. The utilization of NPG as a partial replacement for OPC increases the water-to-cement ratio proportionally compared to the control sample, which can be explained by the anhydrite content of this byproduct. For its part, replacing 10% of OPC with NPG and CWTPS results in a 1.99% decrease in resistance after 28 days in sulfated environments compared to specimens cured in lime water. This protection of NPG against sulfate attack on mortars is based on the fact that SO3 saturation hinders the phase change from AFt to AFm during curing, as demonstrated by the XRD results. Additionally, the inclusion of NPG in mortar mixes increases capillary water absorption by up to 19.8%, while CWTPS, due to its pozzolanic nature, reduces it by up to 5.75%. Finally, this study explores the potential combined use of NPG and CWTPS in mortar mixes as a partial replacement for cement, presenting a viable and sustainable alternative for these cementitious-based construction materials.

Effect of pressure and time on water absorption of coated paperboard based on a modified Cobb test method

This manuscript presents the study of water absorption by paperboard subjected to water at high hydrostatic pressure based on a modified Cobb tester. The new tester is based on TAPPI Standard Test Method T 441; however, the water column can reach up to 550 mm. The evaluation consisted of measurements of water absorption for coated and uncoated paperboard at different exposure times from 5 s to 45 s and water column heights from 10 mm to 500 mm (corresponding to hydrostatic pressures 98 Pa and 4.9 kPa, respectively). The coatings were formulated as a combination of styrene acrylate (SA; two binder levels) and two types of ground calcium carbonates (differing particle sizes) to form the two pre-coating structures: open and closed. The coating weight was 6 g/m2 applied on 210 g/m2 solid bleached board (SBB). In addition, 210 g/m2 uncoated boards were studied. Characterization of the coatings was performed with scanning electron microscopy (SEM), mercury intrusion, and roughness. It was found that the new device properly mimics the conditions of the current Cobb tester. The characterization of the coating also confirmed the presence of more open/larger pores of open coatings, confirming the desired coating structure. The absorption of boards was mainly driven by exposure pressure by comparing with exposure time. This was already evident after shorter periods of exposure time at 5 s and also 15 s exposure time. Paperboards with open coatings showed slightly higher absorption than other boards.

Poly (Lactic Acid) Cellulose Biocomposite Films as Potential Antimicrobial Food Packaging Material

Polylactic acid (PLA)-cellulose bio-composites were developed by incorporating Aloe vera (A. vera) leaf gel at ratios of 100/50 and 50/50. This study aimed to evaluate their physico-chemical, barrier, and antibacterial properties for potential application in sustainable food packaging. Different composite films were prepared and characterized by Fourier-transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), mechanical testing, water absorption, and Ultraviolet (UV) transmission measurements. Their antibacterial activity against E. coli, P. aeruginosa, and S. aureus was assessed through agar diffusion and broth dilution assays. The presence of cellulose significantly affected the properties of the composite films. The 50/50 blend exhibited better chemical resistance and barrier properties compared to the 100/50 blend, highlighting the influence of cellulose content. Both ratios demonstrated promising antibacterial activity against all three target bacteria, while the 50/50 ratio showing pronounced inhibition against E. coli. These PLA-cellulose bio-composite films, with their combined UV-protective and antibacterial properties, present a sustainable and potential alternative to conventional food packaging materials, contributing to a reduced environmental pollution.

Beneficial Effects of Oxide-Based Additives on Li-and Mn-rich Cathode Active Materials

Li- and Mn-rich layered oxides such as Li1.14(Ni0.26Co0.14Mn0.60)0.86O2 (LMR-NCM) are potential next-generation cathode active materials (CAMs) for lithium ion-batteries, promising an increased energy density at lower materials costs compared to state-of-the-art CAMs. However, its commercial viability is still inhibited by its strong gassing, poor cycling stability, and voltage fading, so various approaches such as post-treatments or additives are being investigated. Here, it will be shown that the cycling performance of LMR-NCM//graphite coin-cells is drastically improved when assembled with 300 °C dried glassfiber (GF) separators (“GF-cells”) compared to cells with Celgard (CG) separators dried at 70 °C (“CG-cells”). The origin of this phenomenon is investigated by online electrochemical mass spectrometry (OEMS), TGA-MS, water absorption, and XPS measurements. These reveal that the superior performance of the GF-cells can be ascribed to the bulk water absorption capability of the 300 °C dried glassfiber material as well as its ability to scavenge HF, whereby H2O and HF are produced by the (electro)chemical oxidation of the electrolyte and the decomposition of the LiPF6 salt. Similar performance enhancements can be observed for 300 °C dried SiO2 nanoparticles added to the LMR-NCM cathodes or for an HF/H+ scavenging electrolyte additive.

Gamma radiation impact on dielectrics and RH sensitivity of nylon–carbon–GNP–epoxy composites

AbstractComposites of carbon–graphene nanoplatelets (GNP) epoxy with nylon‐66 interleaving were fabricated and investigated to understand the impact of γ‐irradiation on their dielectrics and relative humidity (RH) sensitivity by capacitance and water absorption measurements. The moisture sensitivity was investigated by measuring memory effect (hysteresis) and response time of the capacitance. Composites were γ‐irradiated at doses of 1000 and 3000 kGy and studied by the same set of measurements. X‐ray diffraction analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy were used to understand the impact of γ‐irradiation on the morphology and surface roughness of the composites. Results of these measurements suggest that 3000‐kGy dose γ‐irradiation produces good chain scission and cross‐linking, resulting in reduced water absorption and a 360% increase in capacitance values. The sensitivity of capacitance for 3000‐kGy γ‐irradiated composite was found to be highest at 40 pF/%RH, and hysteresis was 1.8% RH and not observed in non‐irradiated composites. Based on these observations, it seems that 3000‐kGy γ‐irradiated composite could be a potential candidate for moisture content diagnostics during condition monitoring of the carbon–epoxy structures in several industrial applications and needs to be further investigated.Highlights Composites of carbon–GNP epoxy with nylon‐66 interleaving were γ‐irradiated. 3000‐kGy dose γ‐irradiated composites exhibit 360% increase in capacitance. Sensitivity and hysteresis were higher than those of 1000‐kGy and non‐irradiated samples. Good chain scission and cross‐linking resulted in reduced water absorption.

New Hydrophobic Treatment for the Protection of Gypsum Artifacts

Gypsum has been widely used in traditional and monumental architecture in many countries of the Mediterranean area; however, due to its low water resistance and low mechanical strength, it can be subject to physical, chemical and biological degradation. To improve the preservation of gypsum-based plaster artifacts, a new hybrid inorganic-organic hydrophobic treatment is proposed in this work. This treatment is based on nanometric magnesium hydroxide (Mg(OH)₂) and organically modified silica (OrMoSil), a class of materials with intermediate performances between ceramic materials and polymers. The behaviour of the product was verified both as a protective on gypsum surface, as well as a consolidant added to the mixture of gypsum-based plasters. The treatment does not alter the aesthetic appearance of the surface, as verified through colorimetric analysis. As demonstrated by capillary water absorption and static contact angle measurements, the new hydrophobic protective coating proved to be very effective. Moreover, the new treatment is effective as a consolidant, leading to an improvement of the mechanical properties and to a reduction of the depth of carbonation. The new hydrophobic nanocomposite product is therefore a promising material for the protection and consolidation of gypsum monuments and artifacts of cultural interest.

Influence of fly ash filler on the mechanical properties and water absorption behaviour of epoxy polymer composites reinforced with pineapple leaf fibre for biomedical applications.

This study explores the impact of fly ash (FA) filler on the mechanical, morphological, and water absorption properties of pineapple leaf fibre (PALF)-reinforced epoxy composites for biomedical applications. PALF, sourced from abundant agricultural waste, offers a sustainable alternative to synthetic fibres. Employing the hand layup process, varying wt% of FA (3%, 6%, and 9%) are incorporated into PALF-reinforced epoxy composites with different PALF concentrations (10%, 20%, and 30%). Mechanical assessments, including impact, flexural, and tensile strength, reveal that the introduction of up to 6 wt% FA enhances tensile strength by 65.3%, reaching its peak at this concentration. Flexural strength also improves by 31.9% with 6 wt% FA, while impact resistance reaches its maximum (74.18% improvement) at 9 wt% FA. Water absorption measurements demonstrate a decrease with increased FA content and exposure period, indicating enhanced water resistance. Scanning electron microscopy confirms the uniform distribution of FA, contributing to improved mechanical characteristics and water resistance. Optimality tests using Taguchi and response surface methodology (RSM) further confirm the experimental outcomes, emphasizing the potential of FA to enhance natural fibre-reinforced composites. This research suggests FA as a promising filler to elevate mechanical performance and water resistance in environmentally friendly composites.

Improved engineering model for water absorption in softwoods

Modeling of moisture transfer in porous materials is typically partitioned into liquid transport and vapor diffusion. Coefficients for liquid transport are often derived from laboratory measurements of water absorption by partial immersion. Although the assumption that capillary liquid transport is dominant while vapor diffusion is negligible is a reasonable assumption for mineral-based materials, recent work indicates that it is not representative of water absorption in wood across the grain. This article builds on earlier work and develops an improved engineering model for liquid water transport in softwoods. The approach uses a constant liquid diffusivity value, relies primarily on ordinary hygrothermal property measurements, and partitions vapor and liquid transport in a practical way that is informed by current understanding of wood–water interactions. The model is optimized using one-dimensional simulations calibrated against measured water uptake across a range of softwood species. Laboratory measurements were conducted to investigate key properties of eastern white cedar, which had the highest relative error in a previous version of the model, and to examine the practicality and relevance of vacuum saturation and free saturation for southern yellow pine. The model accuracy is improved by paying closer attention to the moisture storage function and capillary saturation value.

Effect of the strength grade of parent concrete on the performance of recycled aggregate treated by cement-fly ash slurry under prolonged soaking duration

The detrimental effects of quarrying natural resources have contributed to large-scale environmental pollution. Utilizing recycled concrete aggregate (RCA) obtained from construction and demolition waste as a replacement for natural aggregates has become an effective solution for environmental sustainability. However, the inevitably diminished characteristics of the adhered mortar and the existence of an additional interfacial transition zone (ITZ) have negatively suppressed the widespread use of these materials in production lines. The present study aims to comprehensively investigate the effects of a cement-fly ash slurry with a mass ratio of 50% of the total weight of RCA on the microstructure and engineering properties of RCA derived from three different parent concretes with strength grades of 20, 30, and 60 MPa. The RCAs were soaked for 24 h, 48 h, and 72 h to evaluate the long-term effects of the pozzolanic slurry. A sequence of laboratory tests was conducted, including mercury intrusion porosimetry (MIP) test, thermal gravimetric–differential thermal analysis (TG-DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses, and measurements of water absorption and crushing value. The MIP results demonstrated a significant increase in medium capillary and gel pores, and a reduction in large capillary pores in the RCA with an increase in soaking time. TG-DTA results indicated an increase in Ca(OH)2 content during the first 24 h and 48 h of treatment. However, after 72 h of treatment, the Ca(OH)2 content of the treated RCA decreased in all cases. XRD analysis revealed the appearance of a few additional ettringite peaks among the treated RCAs in all cases. SEM images demonstrated the presence of additional hydration products after treatment, which filled the pores and improved the surface texture. Furthermore, after treatment, the crushing value of all treated RCA decreased by 6.0–27.1%, whereas the water absorption decreased by 12.0–30.9% compared to the untreated RCA. Based on several experimental results, the formation of hydration products and the improvement mechanism of RCA from three different parent concretes by slurry treatment with different soaking durations were discussed. In conclusion, a prolonged impregnation time of 72 h yielded a dominant performance, effectively intensifying their inferior properties, regardless of the initial strength grade of parent concrete.

Study on the influence of water ingress on the interface of high strength zinc coated steels and epoxy adhesives

This study aimed to assess the impact of humidity on adhesive joints comprising four different Zn-coated high strength steel substrates (SA, SB, SC, and SD) and two epoxy adhesives (EA and EB) at 70 °C. Several tests were conducted to analyse the effects of humidity on adhesive properties, under both dry and saturated conditions. Gravimetric tests were used to measure water absorption by the adhesives, while mechanical properties were evaluated through bulk tensile tests. Chemical structure changes were examined using Fourier-transform infrared spectroscopy (FTIR), and the glass transition temperature was determined using a DMA-like test. The water immersion behaviour of the substrates was studied through gravimetric tests and surface energy was analysed using contact angle measurements. The overall joint performance was assessed through gravimetric tests, and the mechanical impact of water was evaluated using single lap joint tests on both dry and aged joints, for one week and one month. The findings indicated that EB adhesive absorbed more water compared to EA, which did not reach saturation. FTIR analysis revealed significant chemical degradation in the EB adhesive after ageing, leading to greater deterioration in mechanical properties compared to EA. The bulk substrate tests showed similar surface energy among the substrates, with SA being the only substrate that did not corrode during water immersion. In terms of joint behaviour, cohesive failure was predominant in dry conditions, but as the joints aged, those with EB adhesive experienced a decrease in failure load due to adhesive degradation, while the interface remained strong. Joints with EA adhesive exhibited increasing interfacial failure, indicating weaker interfaces that allowed water ingress between the adhesive and substrate. Consequently, water uptake in the joints was higher for EA adhesive than for EB adhesive, contrary to the behaviour observed at the bulk level. SA and SD substrates demonstrated stronger interfaces with EA, likely due to their higher developed interfacial area ratio, which facilitated mechanical interlocking.

Capillary sorption, thermo physical characterizations and simulation study of an eco-friendly building material reinforced with Chamarrops humilis fibres

ABSTRACT This research introduces an environmentally friendly building material combining clay and Chamaerops humilis fibres, demonstrating substantial potential for enhancing thermal and energy efficiency in construction across diverse climates. The study aims to align construction materials with the heating and cooling requirements mandated by the Moroccan Thermal Building Regulations. Hygroscopic behaviour of the material was evaluated through experiments using gravimetric methods at varying temperatures and humidity levels. The assessment covered a wide air relative humidity range (5.72%–89.8%), enabling measurement of water absorption through capillarity. Thermal conductivity, density, and heat capacity were determined, critical for understanding the material’s thermal and energetic characteristics. Dynamic thermal simulations for a single thermal zone were performed to analyze the material’s impact on heating and cooling loads in different Moroccan climate zones: humid Agadir (zone 1), dry Marrakech (zone 5), and semi-arid Ouarzazate (zone 6). The analysis revealed substantial energy savings potential. The findings demonstrating comply with Moroccan Thermal Regulations, highlighting the efficacy of this composite material in meeting regulatory heating and cooling requirements.

An examining the static and dynamic mechanical characteristics of milled ramie root reinforced polyester composites

This research works discuss about the effective utilization of waste Ramie Root, that has been in reinforced polyester composites, powdered fillers that have not been treated are used. Four different composites plate were formed with compression moulding technique process consisting of 20, 30 and 40% of Powdered Ramie Root with 80, 70 and 60% unsaturated polyester resin, respectively. The maximum mechanical properties were observed for the composite with 30:70 weight volume percentages of milled ramie root synthetic reinforced polyester. The findings show that the glass transition temperature, storage modulus, and loss factors all rise when the composition of composites changes. Additionally, the powder cohesion force (bonding strength) has a greater impact on dynamic mechanical properties. Thermo-gravimetric the inclusion of Ramie Root powder caused the thermal deterioration peak of the composite to move from 370 °C to 418 °C, according to analysis (TGA) conducted under flowing oxygen. According to the measurement of water absorption, the ideal weight ratio of Fiber: Unsaturated Polyester Resin is 30:70, which modifies the fibres’ surfaces and ensures optimal adhesion between the fibre and matrix in composite materials. Scanning electron microscopic investigation is done to ascertain the fracture behaviour of the composite. As a result of their stability, high tensile strength, and bending stiffness, the produced composites can be used in light-load applications by material technologists.

Effect of gamma irradiation on the waste polyethylene/bagasse composites reinforced with flax and sisal fibers for use in wood applications

AbstractDue to their many benefits, including their environmentally benign nature, low cost, biodegradability, and generally good mechanical behavior, natural fibers represent one of the most attractive reinforcing materials. This paper describes the fabrication of green composites based on waste polyethylene (WPE)/bagasse reinforced with flax and sisal fibers. The composites were prepared using the hot‐mixing method in an internal mixer and molded in a hot press with a suitable thickness. This thickness is about 6 mm to ready for measurements belonging to the wood as impact strength, flexural strength, hardness, water absorption, density, and porosity measurements. The prepared specimens will be subjected to gamma irradiation to evaluate the effect of ionizing radiation on the fabricated samples. Furthermore, the thermal behaviors of the fabricated specimens were examined using TGA and DSC techniques. As a result of their superior mechanical performance, sisal, and flax fibers reinforced WPE/bagasse were able to create composites that were suitable for use in wood applications. The mechanical results revealed that composites with flax fiber are superior to composites with sisal fiber. With 30 phr fiber loading, WPE/bagasse thermal stability improved, with composites made of sisal being the best. With increasing fiber loading, the porosity of the composite rises due to the increase in density. Porosity decreases in composites with irradiation due to crosslinking and enhancement of the compatibility between fiber and matrix. Flax composites that have been irradiated exhibit significantly higher thermal stability than those that have not.Highlights Different advantages of natural fibers as their low cost, biodegradability, and generally good mechanical behavior are considered one of the most attractive reinforcing materials. Sisal and flax fibers reinforced WPE/bagasse were able to create composites that were suitable for use in wood applications. Green composites were prepared by the hot‐mixing method in an internal mixer and molded in a hot press with a suitable thickness of about 6 mm to ready for measurements belonging to the wood. Various studied properties were improved via ionizing irradiation due to crosslinking induced in the polymer matrix.

Physical properties of silver fir (Abies alba L.) wood cladding modified by traditional Japanese charring method

Silver fir (Abies alba L.) wood samples were charred on one surface using an enhanced version of the traditional Japanese Yakisugi method. The 15 charred boards obtained from five charring chimneys were divided into three different zones and investigated for their physical properties. The density profile, water absorption after 24 h of water submersion, and Brinell hardness were analyzed. In general, the temperature-time regime, which causes inside surface carbonization, was more evident at the bottom than at the top of the chimney. The density profile of the specimens revealed that the surface charring treatment decreased the surface density of the wood significantly. A gradient was visible from 383 kg/m² at the bottom to 424 kg/m² at the top. Water absorption measurements showed that a thicker carbonized layer could take up more water as a result of increased porosity. While 3,684 g/m² were absorbed at the bottom, the top accounted for only 2,533 g/m². Furthermore, with increasing thickness of the charred layer, the hardness gradually decreased. The average of the charred specimens reached only 3.2% of the hardness of the uncharred back side of the specimens.