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Alkali treatment is commonly used to improve the fibre-matrix bond of plant fibre polymer composites. Still, there needs to be more consensus on the optimal protocol. This study seeks to identify the most effective alkali treatment protocol for flax fibres that enhances their mechanical performance without compromising the fibre strength. Flax fibres were treated with 2% and 5% sodium hydroxide at different soaking times. Single fibre tensile strength test was performed on 243 fibre samples, and the results were analysed using the Weibull distribution model. The effect of the alkali treatment on the fibre morphology was examined using microscopic imaging, functional groups using Fourier-transform infrared spectroscopy, thermal behaviour by thermogravimetric analysis and the fibre moisture absorption behaviour was also investigated. The results indicate that treatment with 2% NaOH for 30 and 60 minutes enhanced the tensile strength of the fibres. Fibre imaging confirmed the breakdown of the fibre bundles using the treatment method. FTIR analysis showed that the treatment reduced the fibres’ hemicellulose content, enhancing the fibres’ thermal and moisture absorption behaviour. The results highlight flax fibres treated with 2% NaOH for 60 minutes as the optimal treatment protocol for flax fibres used as the reinforcing phase in polymer composites. [ABSTRACT FROM AUTHOR]

In the present study, the influence of adding lightweight expanded clay aggregate (LECA) and natural zeolite (NZ) on the geopolymer concrete (GPC) based on ground-granulated blast furnace slag (GGBS) was investigated in terms of density, water absorption, compressive and splitting tensile strengths, and ultrasonic pulse velocity (UPV) at ambient temperature. Two sizes of LECA as the replacement of course and fine aggregates ranging from 0 to 100% were used in order to examine their suitability to produce lightweight GPC (LWGPC). NZ was utilized as a binder in the GPC with up to 15% replacement of GGBS. Test results indicated that the density of GPC decreased and water absorption value was increased with higher LECA percentage, and this behaviour is observed for NZ addition with less intensity. Compressive strength of the lightweight GPC is extremely decreased from 5 to 20% by incorporation of NZ in place of GGBS. Results indicated that LWGPC with 100% LECA compared with the specimens without LECA can effectively decrease the tensile strength by about 50% and the reduction for NZ addition is approximately 15%. The experimental results show that the variation in splitting tensile strength, compressive strength, and UPV of LWGPC is significantly influenced by binder content. A machine learning-based model was created for the mixtures produced within the scope of the experimental study and equations generated from M5p model tree that represents a strong correlation between the actual and predicted values for splitting tensile and compressive strengths with more than 99% of accuracy. [ABSTRACT FROM AUTHOR]

This study examines the viability of using construction waste, specifically recycled brick waste powder (RBWP), as an alternative conventional industrial byproduct (fly ash) in the manufacturing of engineered geopolymer composites (EGC). The EGC mixtures are made with 40 μm diameter and 12 mm length polyvinyl alcohol (PVA) fiber. RBWP replaces class‐F fly ash in EGC by 0, 20%, 40%, 60%, 80%, and 100%. This study produces six distinct EGC mixtures in total. The flexural strength, abrasion resistance, sorptivity, and water absorption of the EGC are investigated. Microstructural characterization is carried out using scanning electron microscopy (SEM). Based on the results, when fly ash is replaced by 40% and 100%, respectively, adding RBWP to the EGC mixes significantly improves flexural strength by 39% and midspan deflection by 169%. Nevertheless, abrasion resistance significantly improves when fly ash is completely replaced with RBWP, even though sorptivity and water absorption increase by about 128% and 240%, respectively. The volume change is reduced by 25.4% when RBWP is used. Furthermore, the SEM study shows that the RBWP undergoes active geopolymerization in the EGC mixes. [ABSTRACT FROM AUTHOR]

Introduction: The formation of yield and quality in maize involves the accumulation of substances such as starch, proteins, and fats, which interact with water within the kernel. Although temporal dynamics of grain moisture and its functional and environmental determinants have been broadly demonstrated, we still do not have a comprehensive understanding of the distribution of water phase within a kernel. Methods: We investigated the relationship between tissue structural traits, including embryo volume (EMBV), endosperm volume (ENDV), vitreous endosperm volume (VEV), floury endosperm volume (FEV), and water content in different phases, such as bound water, semi-bound water, and free water, in maize kernels under different cultivars, nitrogen application rates, and soaking durations by combining low-field nuclear magnetic resonance (LF-NMR) and X-ray microcomputed tomography (μ-CT) for kernels. Results: The results demonstrate that bound water is the major phase (57-82%) in maize kernels, and this proportion decreases with prolonged soaking duration. The bound water content and semi-bound water content positively correlate to ENDV, VEV, and EMBV, whereas free water content correlates to ENDV, EMBV, and VEV in descending order of correlation coefficient. This indicates that water might penetrate the embryo through the pedicel and vitreous endosperm through the pericarp during soaking. Discussion: Finally, we suggested that the proportion of semi-bound water could be a robust indicator to predict moisture content in maize kernels. The study provides a preliminary understanding of the structural basis of water distribution in maize kernels, thereby opening up the potential for designing efficient production systems and breeding cultivars well-suited for mechanical harvesting. [ABSTRACT FROM AUTHOR]

The natural aging process of the human organism leads to both physiological and pathological changes, including tooth loss. This requires dental prosthetic interventions aimed at restoring patients' quality of life. The use of such prostheses necessitates selection of sufficiently strong, aesthetic and biocompatible materials, which also offer ease of shaping. The market for materials used in prosthetic applications offers a wide array of options; however, selection of the most suitable material for specific clinical scenarios can be challenging for dental professionals. This paper continues the comprehensive investigation of the physiochemical and mechanical/functional properties of two commonly used prosthetic—Biocetal and BioHPP—offering a comparative analysis of their characteristics to provide valuable insights for dentists and prosthodontists. The study focuses on in vitro analyses of physiochemical parameters, including density, water sorption, contact angle, and surface roughness. The structure of the materials was examined via scanning electron microscopy. Additionally, microbiological studies were performed using strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. Statistical analysis was performed using Shapiro–Wilk test, Q-Q plot analysis, Grubbs test, and Student's T-test (p < 0.05). The findings indicate that BioHPP demonstrates superior physiochemical and microbiological properties. However, Biocetal exhibit better surface characteristics. Despite its high performance, BioHPP presents certain drawbacks, which may influence dentists' material choice in specific clinical cases, particularly for certain prosthetic restorations. [ABSTRACT FROM AUTHOR]

Cracking increases the vulnerability of concrete structures to aggressive substances in environments. In this study, water absorption of mechanical cracked cement mortar has been monitored using acoustic emission (AE). The AE waves from the cracking and the wetting were both recorded and analysed using wavelet transform. Two analytical methods, ie wavelet energy and empirical mode decomposition (EMD), were employed to determine the entropy value of the acoustic signals. The results show that the signal of water absorption denoised by a 6-level Daubechies wavelet of order 5 (db5) exhibits lower amplitude and attenuates in a much longer duration compared to that of cracking. The time-frequency distribution, using Continuous Wavelet Transform (CWT), indicates that the maximum magnitude of the waves from water absorption is distributed in frequency of 20 ~ 70 kHz as compared to 80~160 kHz for cracking. The power spectral density of AE waves from water absorption is much less than that of cracking due to the different nature of AE sources. The entropy values by empirical mode decomposition (EMD) and wavelet for water absorption are about 0.51 ± 0.05 and 1.44 ± 0.11 of that of cracking, respectively. The distinct characteristics of the waves could be taken to identify the acoustic sources. [ABSTRACT FROM AUTHOR]

The pressing demand for sustainable construction materials has spurred significant research into eco-friendly alternatives to traditional portland cement–based products. Geopolymer mortars, composed of aluminosilicate materials, have emerged as promising substitutes, boasting enhanced mechanical properties, durability, and a reduced carbon footprint. We conducted a comprehensive comparative study on water absorption and various aspects of geopolymer mortars formulated with ground granulated blast-furnace slag, fly ash, and silica fume. The investigation delved into their chemical composition, physical characteristics, and mechanical and durability performance, focusing on the influence of alkaline activator content on activation processes and binder formation. With compressive strengths ranging from 36 to 41 MPa at 56 days, the M10 mix had the highest strength. Assessments for durability against chemical attacks and moisture ingress showed promising results, with water absorption of geopolymer mortar below 12% and other parameters meeting acceptable limits. The incorporation of silica fume in the mortar mix resulted in an evaporation parameter (gel and capillary porosity) of less than 10%. Although the inclusion of ground granulated blast-furnace slag had a slight detrimental effect on the mortar due to its calcium content, mass loss under acid attack was approximately 1.2%. The compressive strength of the mortar reached 35 MPa (M10) after 56 days of exposure to acid in the samples. This article includes a comprehensive discussion on the potential applications and limitations of fly ash, ground granulated blast-furnace slag, and silica fume–based geopolymer mortars. The study contributes significantly to advancing eco-friendly construction materials and promoting a more environmentally conscious built environment. [ABSTRACT FROM AUTHOR]

Concrete carbonation has been proven to be a potential path for reducing the carbon footprint of cement industry. However, since carbonation reaction significantly alters the chemical composition and microstructure of cement-based materials, it is necessary to carefully assess its effects on the transport properties and durability of concrete materials. The goal of this work is to clarify the effects of accelerated carbonation on both the pore structure and long-term water absorption behavior of cement-based materials using CEM II/B-M (T-LL) as the binder. Experimental results show that exposure to CO 2 at a concentration of over 65% for 90 days leads to substantial carbonation of Ca(OH) 2 and other calcium-bearing phases including C–S–H gels. Accelerated carbonation results in a refined pore structure of cement paste, marked by decreased porosity but increased specific surface area accessible to both N 2 and H 2 O . The long-term capillary absorption of non-carbonated mortar observes the square root of time law in the initial stage and then markedly deviates down, which can be well captured by the modified Richards equation accounting for water sensitivity. In contrast, the long-term absorption into carbonated mortar consistently follows the square root of time law, which could be quantified using the conventional Richards equation. This suggests that after accelerated carbonation, the pore structure of cement mortar is less sensitive to water regain, potentially attributed to the changes in the nanostructure of C–S–H gels caused by carbonation. Additionally, carbonated mortar exhibits lower sorptivity and inherent permeability than non-carbonated mortar, indicating that accelerated carbonation decelerates the water transport in cement-based materials. [ABSTRACT FROM AUTHOR]

This study explores the mechanical, water absorption, and erosive wear properties of hybrid polymer composites reinforced with treated hemp, carbon, and basalt fibers. The composites were fabricated using the hand lay-up method, with epoxy resin as the matrix and fillers (CaCO3 and coconut fiber) incorporated to enhance performance. Treated hemp fibers underwent 5% NaOH treatment to improve fiber-matrix adhesion, and ASTM standards were followed for tensile, flexural, and impact tests. Water absorption was monitored over 10 days, and solid particle erosion was assessed under varying impingement angles. Results showed that Sample B2 (20% treated hemp, 6% basalt) exhibited superior mechanical properties, including flexural strength (15% higher than comparable samples) and impact resistance (10% higher). Treated fibers and fillers minimized water absorption, while erosion resistance was maximized in carbon-basalt composites. SEM analysis confirmed uniform fiber dispersion and strong interfacial bonding in optimal samples, leading to improved load transfer and mechanical stability. This study demonstrates the potential of hybrid composites as high-performance materials for automotive, aerospace, and construction applications, emphasizing the critical role of balanced fiber composition and chemical treatments in optimizing material properties. [ABSTRACT FROM AUTHOR]

Transitions seen in the electric properties of water-absorbable poly(2,5-benzimidazole) (ABPBI) films were confirmed by electric conductivity, dielectric constant, and time-domain nuclear magnetic resonance (NMR) measurements. The electric resistance of the films was measured at room temperature using a high-resistance meter, and the dielectric constant at room temperature was measured using an LCR meter in the frequency range of 90 Hz to 8 MHz. The water absorption ratio at equilibrium absorption for the films was 37%, which corresponded to a volume fraction of water of 0.33. The electric conductivity of the films without water absorption was ~1014 S·cm−1, and it increased to ~1010 S·cm−1 with increasing volume fraction, showing a percolation threshold at a volume fraction of 0.025, and remarkable transitions at volume fractions of 0.075 and 0.135. The dielectric constant of the films without water absorption was 3.4, and it increased to 8.1 with increasing volume fraction, showing a transition only at a volume fraction of 0.135. Above a volume fraction of 0.075, where a transition in conductivity was observed, there were two relaxation times at 18–31 μs and 20–93 μs, as determined from the time-domain NMR, and these relaxation times increased with increasing volume fraction. The longer relaxation time increased significantly at a volume fraction of 0.072, which was close to the volume fraction of the transition seen in conductivity. The relationship between the chain mobility of ABPBI and the deterioration in electric insulating properties is discussed. [ABSTRACT FROM AUTHOR]

In this study, a lightweight hierarchical composite was used in various structural applications by combining fox millet husk ash biosilica particles and low-density Amaranthus dubius stem fiber–reinforced in epoxy matrix. Studying the shear strength, wear, and thermal conductivity along with hydrophobic behavior of these hierarchical composites is the primary objective of this work. The composites were fabricated using the hand lay-up method, with biosilica particle loading ranging from 0.5 to 2 vol.% and fiber volume of 30%. The results showed that composite containing 1 vol.% biosilica showed a better shear properties tested by different methods viz in-plane shear strength of 154 MPa, lap shear strength of 24.3 MPa, V-notch rail shear strength of 19.4 MPa, and interlaminar shear strength of 27.08 MPa. However, the composite with 2 vol.% of biosilica particles with 30 vol.% fiber loading had better wear properties with coefficient of friction (COF) of 0.26 and a sp. wear rate of 0.007 mm3/Nm. This composite also has lower thermal conductivity value with 0.182 W/mK and lowest contact angle of 84°. However, the composites are in hydrophobic range even after the addition of biosilica. The results obtained clearly demonstrated that these highly toughened and low weight composites could be utilized as a working material for a variety of applications, particularly in the production of automotive components and structural materials for home infrastructure. [ABSTRACT FROM AUTHOR]

Rapid prototyping, also known as additive manufacturing, is a nascent technology that is gaining traction in the context of environmental concerns and waste reduction, as well as the growing trend towards customized design. The additive manufacturing method, which has applications in diverse fields such as aviation, architecture, biomedical and automotive engineering, has also begun to be utilized in the construction of yachts and yacht hulls within the maritime industry. In this experimental study, the influences of sea water on polylactic acid (PLA) and carbon fiber reinforced polylactic acid (PLA/CF) parts manufactured at different infill rates (20%, 60% and 100%) were investigated. The parts were exposed to sea water for three different periods (1, 5, and 10 days) and subsequently subjected to wear tests. The dimensional accuracy, surface roughness, hardness, water absorption, volume loss, and friction coefficient of parts were measured and calculated. Additionally, the worn surfaces of the parts were investigated using field emission scanning electron microscope (FESEM) images. The findings indicate that PLA and PLA/CF parts can be produced with high dimensional accuracy. Furthermore, it can be reported that the water absorption of PLA/CF parts increased, particularly with an increase in the infill rate, while the volume loss decreased. Obtained results indicate the necessity of optimizing the 3D printing parameters and the relationship between the ambient conditions and the wear performance of the 3D printed parts. Highlights: 3D printing is a highly promising method for the production of polymer composites.A pioneering study into the effect of infill rate and water absorption on the wear performance.Coefficient of friction values of PLA and PLA/CF parts ranged between 0.37 and 0.75.PLA/CF mostly exhibited higher volume loss than PLA with water absorption.Volume loss declines with a raise in the infill rate from 20% to 100%. [ABSTRACT FROM AUTHOR]

Wood plastic composites (WPCs) offer a means to reduce the carbon footprint by incorporating natural fibers to enhance the mechanical properties. However, there is limited information on the mechanical properties of these materials under hostile conditions. This study evaluated composites of polypropylene (PP), polystyrene (PS), and polylactic acid (PLA) processed via extrusion and injection molding. Tests were conducted on tensile and flexural strength and modulus, heat deflection temperature (HDT), and creep analysis under varying relative humidity conditions (10% and 90%) and water immersion, followed by freeze—thaw cycles. The addition of fibers generally improved the mechanical properties but increased water absorption. HDT and creep were dependent on the crystallinity of the composites. PLA and PS demonstrated a superior overall performance, except for their impact properties, where PP was slightly better than PLA. [ABSTRACT FROM AUTHOR]

Mechanical properties were evaluated for bio-natural fiber-reinforced epoxy hybrid composites made with varying amounts of jute, banana stem leaves (BSL), and tamarind shell powder (TSP). Each composite design had varying weight percentages of jute and BSL (5 to 25%) and a consistent mix of TSP (10%) and epoxy resin (60%). The tensile strength, flexural strength, interlaminar shear strength (ILSS), impact strength, hardness, and water absorption were examined. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to investigate chemical bonding and morphology. The findings indicated a relationship between fiber and filler content and mechanical properties of composites, with 20% jute fiber content resulting in the highest performance. The tensile strength of the composite increased by 24.6%, rising from 32.4 MPa for the 5% jute and 25% banana stem leaves (5J25BSL) composite to 40.4 MPa for the 20% jute and 10% banana stem leaves (20J10BSL) composite. Similarly, the flexural strength saw a 27.9% improvement, increasing from 67.2 MPa in the 5J25BSL composite to 86.0 MPa in the 20J10BSL composite. The impact strength also experienced a notable increase of 39.1%, moving from 2.56 J for the 5J25BSL composite to 3.56 J for the 20J10BSL composite. These results highlight significant improvements in all three properties, as the proportion of jute in the composite increased and the proportion of banana stem leaves decreased. This research influences material selection for engineering applications and informs the development of specialized composite materials. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) with black locust wood flour and maleic grafted polypropylene were used to prepare wood plastic composites (WPC) by injection molding. The effect of the addition of nano titanium oxide (nano TiO2) on the properties of the composites was investigated. The specimens were weathered in an accelerated weathering apparatus using a xenon arc lamp for 2000 h. The physical properties of the composites were evaluated by colorimetry, water absorption, and thickness swelling before and after weathering. Mechanical properties of WPC were also determined before and after weathering. The WPC containing 0.75 phr nano TiO2 showed an improvement in the flexural and tensile strength and flexural and tensile modulus while the WPCs containing 0.2 phr nano TiO2 showed an improvement in the impact strength. The UV resistance of the WPCs also improved with the incorporation of nano TiO2 powder into the composites. Both water absorption and thickness swelling were found to be reduced by the incorporation of nano TiO2 into WPC. [ABSTRACT FROM AUTHOR]

Over the past decades, significant efforts have been made to prepare biofilms. These efforts aim to achieve biopolymeric films from fruits and vegetables waste with soluble and biodegradable new films. In the current study, biopolymeric films were prepared by the starch extracted from banana peel and potato peel and the mechanical and physical properties of the prepared samples were studied. The mechanical property showed that tensile strength decreased by increasing the banana peel starch content whereas the percentage elongation at break was increased. The swelling studies revealed that the weight of the films increased when the film was soaked in distilled water. Biodegradation studies showed biopolymeric films with potato peel composition of was 60% (P60) and 100% (P100) were completely degraded in 16 days. Thermogravimetric analysis (TGA) results indicated an increase in the degradation rate compared to the biofilms prepared using neat banana and potato peel starch. Scanning electron microscopy (SEM) images suggesting two-phase morphology which shows incompatibility of the blends prepared by potato and banana starch. The pure potato peel-based starch film showed good results compared to other compositions as well as neat banana peel starch based films. Based on the results obtained for 100% potato peel shows higher values compare to other compositions. The results suggested that the prepared biopolymeric films could be mainly used in wrapping applications and food packaging where load bearing properties is of least importance. [ABSTRACT FROM AUTHOR]

The effectiveness study results related to "soft" multi-stage crushing mode of concrete scrap are presented. During the research it was found that the processing of concrete scrap using this technology can significantly improve the characteristics of the secondary concrete aggregate, namely crushability, water absorption and voids. It is achieved by reducing the content of cement bound stones in the secondary crushed stone. Significant volumes of the dispersed material formed as a result of such processing can be used as a fine filler part at production technology of the self-compacting concrete. An optimum organic-mineral additive based on nanoparticle with a superplasticizer, which allows to obtain a homogeneous concrete mixture with additional stabilization properties was used for self-compacting concrete. The stability of the rheological characteristics of the modified cement systems will be insured if an optimum amount of organic-mineral additive is used. It was revealed that 28 days strength of a self-compacting concrete with concrete scrap crushing products content reaches more than 55,6 MPa, hardened under normal conditions and more than 75 MPa after one year under air-dry conditions. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the material properties of polymer-infiltrated zinc oxide networks (PICN) and the effect of using a phosphate monomer-containing primer applied before polymer infiltration. A total of 148 ZnO-network (zinc oxide) specimens were produced: n = 74 were treated with a primer before polymer infiltration and light curing, while the remaining specimens were untreated. Each group was divided into two subgroups (n = 37) based on the infiltrating polymer: UDMA (aliphatic urethane-dimethacrylates)-TEGDMA (triethylene glycol-dimethacrylate) or BisGMA (bisphenol A-glycidyl-methacrylate)-TEGDMA. Additionally, n = 7 specimens of each polymer type were prepared for comparison. Then, biaxial flexural strength was measured before and after 150 days of water storage at 37 °C, including 37,500 thermal cycles (5 °C to 55 °C). The Vickers hardness, surface roughness, and water absorption at 37 °C were also tested. The initial biaxial flexural strength was reduced in the ZnO network specimens compared to in the pure polymers. Primer application improved the flexural strength, though the strength of BisGMA-TEGDMA significantly decreased after water storage. The ZnO network increased hardness, and the polymer-infiltrated networks showed higher roughness post-grinding and absorbed less water than the pure polymer groups. The ZnO networks did not improve the flexural strength over that of the pure polymers. However, the primer's positive impact and the network's long-term stability suggest potential if the network structure can be modified to contain thicker, more stable branches. [ABSTRACT FROM AUTHOR]

Buoyancy material technology is of paramount importance for the development of marine engineering. In this study, a novel carbon fiber buoyancy material (CFBM) is designed and prepared by utilizing composite circular tubes with light weight and high strength. To reveal the failure mechanism under hydrostatic pressure, a finite element model (FEM) based on the three-dimensional Hashin and Yeh failure criterion is developed and validated experimentally. Both the simulated and experimental results indicate that the hydrostatic strength of the CFBM is mainly determined by the buckling of carbon fiber tubes located at the edges of the CFBM. Parametric analysis is conducted to investigate the effect of the number of unit-cells, length, and wall thickness of carbon fiber tubes on the mechanical properties of the CFBM. In addition, a 60-day water absorption test of the CFBM at 12.5 MPa is conducted to characterize its durability. Experimental results indicate that the maximum water absorption rate of the CFBM is 0.59% and the hydrostatic strength is reduced by only 7.97% during the 60-day test period. Finally, the designed CFBM is used at the water depth of 1000 m as buoyancy material. Compared with traditional buoyancy materials, the proposed CFBM has significant advantages in both hydrostatic strength and density. This work has broad engineering application prospects and is of high significance for promoting the implementation of carbon fiber composites in the ocean engineering field. [ABSTRACT FROM AUTHOR]

The effect of printing layer thickness and infill percentage on the water intake ability and mechanical properties of 3D printed PLA (Poly Lactic Acid) parts are explored in this research article. This article is of particular interest because PLA components are typically hydrophilic, preventing their application in humid environments. Tensile and bending test samples were prepared using 1.75 mm PLA filament with infill percentages varying from 50–100% and 0.1–0.3 mm layer thickness. The design of experiments was made using a central composite design to perform the experiments. The water absorption tests were conducted as per ISO 62:2008. The bending and tensile properties increases with the increase in infill percentage and minimum layer thickness. Adaptive Neuro-Fuzzy Interface System (ANFIS) and Artificial Neural Network-Teaching Learning Based Optimization Algorithm (ANN-TLBO) was used to develop an adaptive model between the input parameters and the mechanical properties. The models were evaluated using statistical indices such as coefficient of determination ( R 2 ), root mean square error (RMSE) and mean absolute error (MAE). The R 2 , RMSE and MAE values obtained using ANN-TLBO for tensile and bending tests were 0.99, 0.01 and 0.99, 0.008 and 0.11, 0.12 respectively. It is observed that ANN-TLBO predicted close results with the experimental value for tensile and bending strength. [ABSTRACT FROM AUTHOR]

As ecological architecture and green buildings have become essential in the fight against climate change, earthen architecture has an undoubted role to play in achieving this goal because of its numerous benefits. To help providing a better understanding of the behavior of earthen materials to fulfill modern architectural needs and to preserve earthen heritages, this study aims to investigate the effect of stabilization using Portland cement and quicklime and that of reinforcement using date palm fibers on the compressive creep, ultrasonic properties, and swelling of adobes, besides their impacts on physical characteristics. One of the earthen heritages in Algeria is taken as a case study, and various adobe mixes were examined to attain this objective. The outcomes revealed that stabilization overall improved the properties of adobes, unlike the mutable impact of fibers. Stabilizers played an important role in reducing creep, while fibers reduced the creep of the unstabilized adobes and those with 6%PC-3%QL, but withdrew the positive effect that was offered by binders for adobes with 10%QL and 3%PC-6%QL. Water absorption and swelling were reduced by stabilization, but both increased with the presence of fibers. The changes in ultrasonic characteristics showed a good correlation with those of compressive strength. [ABSTRACT FROM AUTHOR]

This work introduces a new mixing technique for producing wood-plastic composites. The main constituents of the wood-plastic composites are recycled low-density polyethylene and residual dust from routing medium-density fiberboard. The new mixing technique depends on separating the fibers and the polymer during the melting stage of the polymer to avoid the degradation of the fibers due to heat. Physical tests including a water absorption test and a thickness swelling test were applied on specimens produced with the single screw extruder and a new mixing technique, with different fiber-polymer weight ratios (50–50%, 55–45%, 60–40%, 65–35%, and 70–30%). It was found that at a (70–30%) mixing ratio, a reduction in water absorption of about 70% and 67% for densities of 1100 and 1250 kg/m3, respectively was reached. While at a (50–50%) mixing ratio, a reduction of about 24% and 14% for densities of 1100 and 1250 kg/m3, respectively was accomplished. In general, the resistance to water absorption and thickness swelling was observed to be improved for the new mixing technique for all mixing ratios compared to the single-screw extruder. [ABSTRACT FROM AUTHOR]

In recent years, natural fibers have gained more significance in a variety of civil and industrial applications, such as concrete, beams, and slabs. In addition to producing bamboo fiber reinforced epoxy 16 mm diameter biocomposites rod and biochar filler reinforced epoxy biocomposites, this study used compressive molding. Using the stacking sequence RC, RFC, R1-C, R2-C, and R3-C, five different composite rods were created with 35 weight percent (wt%) BF and BC wt% levels of 1%, 3%, and 5% biochar filler substituted with 65% epoxy. Accordingly, studies on bamboo biocomposite rods using various weight-to-content ratios of biochar filler and fiber have been conducted. To further assess the biocomposites rod, mechanical, physical morphology, and water absorption tests were performed. The results demonstrated that the rod morphologies (SEM) of the filler-reinforced biocomposites rod enhanced the fiber-to-resin bonding, which enhanced the mechanical and physical properties. Compared to the other four biocomposites, the R2-C biocomposite, which contains 3 wt% biochar filler and 35 wt% bamboo fiber, exhibits superior mechanical qualities, including outstanding compressive (84.62 N/mm2), tensile (37.1 MPa) and flexural (62.5 MPa) strength. The density results also showed that R2-C biocomposite had the highest density (1.26 g/cc). This investigation recommended the possibility of introducing bio-fiber obtained from waste agricultural residues into biocomposite rods. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate some of the properties of ash (Fraxinus excelsior L.) wood treated at a temperature of 185 °C for 3 h. We tested the samples' physical properties, including their dimensional stability in the form of water absorption and radial/tangential swelling and their surface roughness, as well as their mechanical characteristics such as Brinel hardness and bending strength. Our results show that the water absorption and swelling values of the samples improved, ranging from 27% to 32% and from 21% to 46%, respectively. Also, the Brinell hardness of the thermally treated wood registered a slight decrease from 19.5 N/mm2 to 15.2 N/mm2 in the radial direction and from 15.7 N/mm2 to 12.2 N/mm2 in the tangential direction. It appears that the bending resistance of the samples decreased, which is generally thought to be an adverse effect of heat treatment on any wood species. [ABSTRACT FROM AUTHOR]

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study proposes to analyze the chemical composition and the hydration kinetics of soryz (Sorghum Oryzoidum) grains in water at different temperatures (20, 30, 40, 45, 50, and 60 °C). The analyzed soryz variety presented a starch content of over 70%, and protein of about 10%, with an important supply of amino acids and a good source of K, Mg, and Ca. The efficiency of the hydration process was studied by applying Peleg's model, which predicted water absorption by soryz under the experimental conditions. With increasing temperature, the Peleg's rate constant, K1, and capacity constant, K2, decreased from 251 to 239 min/% and 2.52 to 2.49%−1, respectively. Fick's second law was used to calculate the diffusion coefficient values. These values increased linearly with the temperature increase from 20 to 50 °C, ranging from 0.65 × 10−11 to 1.54 × 10−11 m2/s. They decreased with the subsequent rise in the environmental temperature up to 60 °C, 1.49 × 10−11 m2/s. The activation energy of soryz grains was 23.86 kJ/mol. The Arrhenius equation satisfactorily described the temperature dependence of the diffusivity coefficient. The results regarding the hydration kinetics of the soryz grains obtained are decisive in preparing this cereal for further use in meat analog manufacture. [ABSTRACT FROM AUTHOR]

This study examined the impact of various foam concrete production techniques on pore size distribution and its water absorption properties. Techniques such as the use of a cavitation disintegrator and a turbulent mixer were employed to produce foam concrete. Six foam concrete compositions, with dry densities ranging from 820 to 1480 kg/m3 and compressive strength up to 47 MPa, were prepared. A novel method for digital image correlation was applied to analyse the pore size distribution within the foam concrete specimens. The manufactured foam concrete specimens' porosity and water absorption indices were determined. The experimental results, including compression strength and water absorption, indicated that the production technique significantly affects the pore size distribution in foam concrete, impacting its mechanical and durability properties. Compressive strength was assessed at curing intervals of 7, 28, and 180 days. Cavitation technology was found to promote the formation of a finer porous structure in foam concrete, resulting in enhanced strength properties. [ABSTRACT FROM AUTHOR]

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The paper presents the results of a study of the porous structure and sorption characteristics of technogenic foam silicate obtained in the process of complex processing of waste ore raw materials and modified in the process of thermochemical treatment in the gas phase of hydrocarbons. The parameters of thermochemical modification of the surface of foam silicate to obtain an oleophilic adsorbent for the removing of petroleum products from aqueous media, as well as the modes of its regeneration, have been determined. It has been established that the degree of extraction of petroleum products from water by the resulting adsorbent under static conditions is 99.8%. [ABSTRACT FROM AUTHOR]

By volume, cement concrete is one of the most widely used construction materials in the world. This requires a significant amount of Portland cement, and the cement industry, in turn, causes a significant amount of CO2 emissions. Therefore, the development of concrete with a reduced cement content is becoming an urgent problem for countries with a significant level of production and consumption of concrete. Therefore, the purpose of this article is to critically investigate the possibility of using inert granite dust in combination with highly active silica fume in reactive powder concrete. The main physical and mechanical properties, such as the compressive strength at different curing ages and the water absorption, were studied using mathematical planning of experiments. The consistency and microstructure of the reactive powder concrete modified with granite dust in combination with silica fume were also analyzed. Mathematical models of the main properties of this concrete are presented and analyzed, and the graphical dependencies of the influence of composition factors are constructed. A more significant factor that affects the compressive strength at all curing ages is the silica fume content, increases in which to 50 kg/m3 lead to a 25–40% increase in strength at 1 day of age, depending on the granite dust content. In turn, an increase in the amount of granite dust from 0 kg/m3 to 100 kg/m3 in the absence of silica is followed by an increase in strength of 8–10%. After 3 days of curing, the effect of granite dust becomes more significant. Increases in the 28-day strength of 25%, 46% and 56% were obtained at a content of 50 kg/m3 of silica fume and 0 kg/m3, 100 kg/m3 and 200 kg/m3 of granite dust in concrete, respectively. It is shown that the effect of inert granite dust is more significant in combination with silica fume at its maximum content in the range of variation. The pozzolanic reaction between highly active silica and Ca(OH)2 stimulates the formation of hydrate phases in the space between the grains and causes the microstructure of the cement matrix to compact. In this case, the granite dust particles act as crystallization centers. [ABSTRACT FROM AUTHOR]

The chemical composition and quality attributes of wheat bread enriched with cereal coffee were analyzed, with additive incorporated as a partial replacement for wheat flour at levels of 2%, 4%, 6%, 8%, and 10%. The rheological properties of the bread dough, consisting of wheat flour and cereal coffee blends, were evaluated using farinograph and extensograph analyses. Results indicated that the addition of cereal coffee decreased flour water absorption, extended dough stability, and increased dough softening. Dough containing cereal coffee showed greater resistance to stretching and reduced extensibility. However, the incorporation of cereal coffee led to a reduction in bread volume and an increase in crumb hardness and density, especially when the substitution level exceeded 6%. In terms of nutritional composition, the levels of dietary fiber, ash, fat, and total polyphenols increased with higher cereal coffee content, while crumb brightness decreased, and yellowness and redness intensified. Overall, the study suggests that cereal coffee can function as a valuable ingredient in bread; however, substitution levels should ideally be kept below 8% to preserve acceptable sensory qualities. [ABSTRACT FROM AUTHOR]

An alternative particle-reinforced composite has been developed using inexpensive waste prawn shell–derived chitin reinforced vinyl ester thermoset resin. The effects of different weight percentages of chitin particles and various particle sizes of chitin particles on the thermal, mechanical, and morphological characteristics of vinyl ester resins were investigated. Composites made of chitin with different weight percentages (0%, 10%, 20%, and 30%) and various particle sizes (300 μm, 425 μm, and 600 μm) were prepared by compression molding. This research evaluates the impact of particle size varying with weight percentages of filler particles influencing the strength such as tensile strength, flexural strength, impact strength, and hardness of composites. These properties increase with addition of the filler content while decreasing with increasing filler particle size. As an outcome of the work, the prepared composites showed that the mechanical properties of the composites had a maximum value at 20% loading of 300-μm filler in comparison to filler of 425 and 600 μm. The tensile strength of pure vinyl ester showed 65 MPa, and it increased to 99 MPa for 20% filler of 300-μm size. Similar observation was observed for other mechanical properties such as the tensile modulus, flexural strength, flexural modulus, and impact strength. After 20 wt% of filler, loading content causes the microparticles to aggregate, which reduces the composites' strength. This decrease in strength can be attributed to the reduced mechanical interlocking between vinyl ester chains and chitin particles due to smoothening of the chitin particle surface. At the same time, the entanglement between the vinyl ester chain moieties was insufficient to impart effective stress transfer at this high concentration of chitin particles. However, the elongation at break had dropped due to increasing in the filler content and size. The virgin vinyl ester resin had elongation at break of 4.0%, and it decreased to 2.6% when the particle size increased 600 μm of 30% loading of filler. It also observed that increasing the filler material and particle size of the filler affects the composites' ability to absorb water. While increasing the filler content, there is a drop in chemical resistance of the composites. Samples revealed that the higher chemical resistance nature of biocomposite in the order of CCl4 > H2SO4 > NaOH is noted due to the hydrophilic nature of filler. SEM analysis was done to study the composite morphological behavior of the particle distribution and agglomeration for vinyl ester containing 425 μ (20%) chitin filler. The developed vinyl ester/chitin filler biocomposite can be a potential source of sustainable composite products for a rapidly growing ecofriendly urban development. [ABSTRACT FROM AUTHOR]

Highlights 3D printing technology has transformed the production of complex sandwich composite structures and offers exceptional control over material selection. PLA‐based composites are favored for load‐bearing applications due to their renewability and durable mechanical properties. However, their interaction with water poses a major challenge as moisture can severely affect their performance. This study investigates the effects of water absorption on the mechanical properties, energy absorption, and failure modes of 3D‐printed sandwich composite structures made of PLA‐based materials (PLA, PLA–Carbon, and PLA–Wood) under quasi‐static loads such as flatwise, in‐plane, and flexural tests. The results show that PLA–Wood has the highest water absorption among the composites due to its hydrophilicity, resulting in a significant reduction in compressive strength and Young's modulus by 19 and 9%, respectively, in flatwise tests, due to severe degradation. In contrast, PLA–Carbon shows superior energy absorption with values of 277.91, 10.74, and 1.73 J in flatwise, in‐plane and flexural tests, respectively, compared to 163.83, 2.47, and 1.17 J for PLA–Wood. This difference results from the ability of PLA–Carbon to deform in a controlled deformation, whereas PLA–Wood is susceptible to severe structural deformation. These results emphasize the durability of PLA‐based composites for load‐bearing applications, especially in moisture‐prone environments. Quasi‐static response on 3D‐printed PLA composites under water exposure. PLA–Wood has a higher water absorption because of its hydrophilic nature. The hydrophobicity of PLA–Carbon leads to remarkable strength and stiffness. PLA–Carbon has great energy absorption, which enhances its retained ductility. The failure modes are dependent on the PLA composite materials against water. [ABSTRACT FROM AUTHOR]

Additive manufacturing of concrete (3D printed concrete, 3DPC), is an emerging technology with numerous possible applications and benefits for the digital transition of the construction industry. At the same time, there remain open questions about the environmental suitability of 3DPC. One such aspect is its circularity, i.e. recyclability. Therefore, in this study, the viability of recycling 3DPC is studied on normal- and high-strength 3DPC concretes produced with 0-100% of fine recycled aggregate (fRA). After testing for basic mechanical properties, the specimens were crushed and new (2nd generation) fRA were obtained and tested. The results point to a high potential for recyclability of 3DPC and fRA conducive to multirecycling and CO2 uptake through carbonation. [ABSTRACT FROM AUTHOR]