J. Compos. Sci., Volume 10, Issue 6 (June 2026) – 50 articles

With the rapid development of the hydrogen economy, Type IV composite pressure vessels have emerged as the core components of on-board hydrogen storage systems. However, accurate fatigue life prediction remains a critical bottleneck limiting their design optimization and safe operation. Existing methods often exhibit prediction errors exceeding ±50% due to the inherent scatter, anisotropy, and complex service environments of composites. This study proposes an improved simulation method for fatigue life prediction of Type IV cylinders. Systematic tension–tension fatigue tests were conducted on carbon fiber-reinforced polymer (CFRP) laminates at four ply angles (0°, ±15°, ±30°, ±45°) and PA6 liner at three temperatures (−30 °C, 25 °C, 82 °C) to establish comprehensive S-N curve databases. The results reveal that ply angle is the predominant factor governing CFRP fatigue performance, while temperature significantly influences PA6 behavior, and failure mode transitions from fiber fracture to matrix-dominated damage as ply angle increases. A fatigue analysis model was developed in nCode, incorporating the ply fatigue Algorithm to characterize the anisotropic fatigue behavior of CFRP overwraps. Full-scale validation on Type IV cylinders under cyclic pressure (2–87.5 MPa) confirmed the method’s effectiveness, achieving prediction errors of 11.5% and 35.3% for the two failed specimens, with failure locations well predicted. This study provides a rapid and reliable engineering calculation method and data support for the anti-fatigue design, safety assessment, and life management of Type IV cylinders. Full article

In this study, free vibration analysis of three-layer sandwich panels with cores based on a triply periodic minimum surface (TPMS) and graphene platelet-reinforced composite (GPLRC) faces is performed. Four different geometries including cylindrical, spherical, saddle and flat panels were investigated and the governing equations were solved using higher-order shear deformation theory (HSDT) extracted from Hamilton’s principle. The accuracy and precision of the presented analytical method is verified by comparing the dimensionless natural frequencies with reference studies. Then, the effect of various parameters including panel geometry, core topology type and graphene weight percentage on the vibration response was investigated. The results show that adding graphene to the face layers significantly increases the natural frequencies and improves the overall stiffness of the structure. In addition, the frequencies of the panel may be controlled through different patterns and topologies. Also, double-curved panels, especially spherical geometries, present the highest fundamental natural frequency. The findings of this research could play an important role in the design and performance evaluation of advanced structures with TPMS cores and nanoscale reinforcement. Full article

The growing demand for sustainable construction materials has led to significant advancements in ultra-high-performance concrete (UHPC), with a particular focus on geopolymer-based systems as an alternative to conventional cementitious binders. This review explores the latest developments in sustainable Ultra-High-Performance Geopolymer Concrete (UHPGPC) by analysing key material composition, mechanical, durability and microstructural properties. The incorporation of ground granulated blast furnace slag (GGBFS), silica fume (SF), and fly ash (FA) has demonstrated notable improvements in compressive strength, durability, and workability. Additionally, the use of activators such as sodium silicate and sodium hydroxide optimizes geopolymerization, resulting in a denser microstructure and enhanced mechanical performance. This review highlights the critical role of fibre reinforcement in UHPGPC, where steel fibres (SFs) and hybrid fibres significantly enhance compressive and tensile strength, as well as crack resistance. The inclusion of waste materials such as rice husk ash and recycled glass promotes sustainability by reducing CO₂ emissions while maintaining structural integrity. However, higher waste-glass content may adversely affect bonding due to its smooth surface texture. The findings highlight the potential of UHPGC as a high-performance, eco-friendly alternative to traditional cement-based UHPC. By integrating industrial by-products and alternative activation techniques, UHPGPC can contribute significantly to the global shift towards sustainable and low-carbon construction materials. Full article

Retrofitting existing buildings has become a critical strategy for reducing energy consumption, improving thermal comfort, and achieving carbon reduction targets in the built environment. Among retrofit measures, wall insulation plays a pivotal role in minimizing heat loss and enhancing building energy efficiency. Conventional insulation materials, although effective, are often associated with high embodied energy, limited recyclability, and environmental concerns. Consequently, bio-based composite materials derived from natural fibers, agricultural residues, and renewable binders have emerged as promising sustainable alternatives. However, the moisture sensitivity of lignocellulosic materials remains a major challenge that can compromise thermal performance, durability, and long-term service life. This review provides a comprehensive and critical assessment of bio-based hydrophobic composite panels for wall insulation in retrofit applications. Unlike previous reviews that have primarily examined bio-based insulation materials, natural-fiber composites, or hydrophobic modifications separately, this study integrates these interconnected research domains within a unified framework. The review systematically examines raw material selection, composite panel manufacturing processes, hydrophobic surface-engineering strategies, thermal and moisture-related performance, durability characteristics, retrofit implementation approaches, and sustainability considerations. The analysis demonstrates that hydrophobic modification significantly reduces moisture uptake, enhances dimensional stability, and preserves thermal-insulation performance under varying environmental conditions. Natural-fiber-based composites, including hemp, flax, jute, bamboo, coconut fiber, and agricultural residues, exhibit competitive thermal conductivity (λ) values while offering reduced environmental impacts compared with conventional insulation materials. Furthermore, the integration of advanced hydrophobic treatments improves resistance to water penetration, biological degradation, and freeze–thaw damage, thereby increasing the long-term reliability of retrofit insulation systems. Full article

This study investigates the residual web crippling behavior of pultruded glass fiber-reinforced polymer (P-GFRP) hollow sections after exposure to elevated temperatures. The primary objective is to evaluate the combined influence of temperature and loading configuration on web crippling capacity, failure mechanisms, and structural performance, and to develop practical prediction models for engineering applications. A total of twenty pultruded GFRP hollow section specimens were exposed to temperatures of 24 °C, 200 °C, 250 °C, 300 °C, and 350 °C and tested under four loading configurations: End Ground (EG), Interior Ground (IG), End Two Flange (ETF), and Interior Two Flange (ITF). In addition to web crippling tests, tensile, SEM-EDS, TGA-DSC, DMA, and FT-IR analyses were conducted to investigate the mechanical, thermal, and microstructural degradation mechanisms. The results showed that elevated temperatures significantly reduced the web crippling capacity, with strength losses reaching up to 80% at 350 °C due to matrix degradation, fiber–matrix debonding, and loss of structural integrity. Among the investigated loading configurations, IG exhibited the highest load-carrying performance, whereas ETF experienced the greatest capacity reduction. A temperature-dependent reduction factor and unified empirical prediction equations were developed and demonstrated good agreement with the experimental results, with experimental-to-predicted ratios ranging from 0.97 to 1.15. The findings provide valuable insight into the post-fire behavior of pultruded GFRP hollow sections and offer practical guidance for the design, assessment, and fire safety evaluation of GFRP structural members exposed to elevated-temperature environments. Full article

The excessive emission of greenhouse gases (CO₂, CH₄, SF₆, and CF₄.) is a primary driver of global climate change, making the development of efficient adsorption and separation technologies critically important for achieving carbon reduction goals. Metal–organic frameworks (MOFs) have attracted considerable attention in this field due to their crystalline porous structures, ultrahigh surface areas, and tunable pore architectures. However, pristine MOFs face significant bottlenecks including poor water stability, high bed pressure drops caused by their powdered form, and limited mass transfer, which severely hinder their industrial application. The integration of MOFs with functional materials such as carbon materials, polymers, metal oxides, and porous SiO₂ offers a synergistic strategy to overcome these limitations. Carbon materials provide hydrophobic barriers and mesoporous transport channels, polymers enhance processability and mechanical strength, metal oxides introduce basic sites for enhanced chemisorption, and MOF-on-MOF heterostructures enable atomic-level interfacial integration and pore synergy. This review systematically summarizes recent advances in MOF composites for the separation of CO₂, CH₄, and fluorinated greenhouse gases (SF₆, CF₄.), with an emphasis on design strategies, structure–performance relationships, and synergistic mechanisms across different composite types. Finally, the current challenges including scalable synthesis, long-term stability, and separation performance under realistic conditions are discussed, and future directions toward rational design and functional synergy for industrial carbon capture and fluorinated gas emission reduction are envisioned. Full article

In this study, the development of a novel machine mount utilizing an advanced polymer composite and porous materials is presented. Initially, a preliminary evaluation of the proposed materials was conducted, focusing on their static mechanical properties and their dynamic properties, and assessed through loading–unloading cycles and Dynamic Mechanical Thermal Analysis (DMTA). All tests were performed at the coupon scale, with specimens manufactured via Fused Filament Fabrication (FFF). Subsequently, a conceptual design incorporating the proposed materials was developed, and functional prototypes were fabricated using multi-material additive manufacturing techniques. The structural integrity of the prototypes was evaluated by analyzing their oscillatory response and damping behavior under laboratory-scale conditions, with transmissibility metrics extracted to quantify performance. The results indicate that all three prototypes exhibit adequate damping for machine mounting applications, ranging between 5% and 20%, with the porous variant demonstrating the highest damping performance (20.9%). In terms of load-bearing capacity, the porous configuration withstood loads up to 10 kN, while the standard TPU variant sustained up to 20 kN. The carbon-fiber-reinforced configuration exhibited the highest mechanical performance, tolerating loads up to 50 kN without significant structural failure. Full article

Glass fiber reinforced epoxy laminates (GFRP) are increasingly used in structural applications where combined mechanical and environmental loading is unavoidable, such as in the aerospace, naval, automotive, and petrochemical industries. This study investigates the influence of aggressive environments on the impact response and damage mechanisms of GFRP laminates. Specimens were immersed in acidic (hydrochloric and sulphuric) and alkaline solutions (sodium hydroxide), oil (automotive engine and automotive brake fluid), and cementitious solutions (cement and metakaolin mortars) for a determined period to simulate severe service conditions. Low-velocity impact tests were subsequently performed to evaluate the residual impact performance in terms of absorbed energy, maximum force, and damage extent. The results demonstrate that environmental exposure significantly alters impact behavior, mainly through matrix plasticization, fiber-matrix interface degradation, and microcrack development. For shorter immersion times (12–30 days), the solutions are not highly aggressive, as the decrease in elastic energy remains below 15%, with cementitious solutions showing the lowest reductions even for longer exposure periods. In contrast, longer immersion times in alkaline solution, DOT4 oil, and metakaolin mortar lead to more severe deterioration, with elastic energy reductions between 30% and 40%, the most aggressive condition being immersion in NaOH for 36 days, which caused a 37.4% decrease. Alkaline and automotive brake fluid oil environments induced the most severe degradation, leading to reduced impact resistance and increased damage propagation. Full article

This study aims to solve the problems of the high carbon emissions, poor compatibility, and insufficient storage stability of conventional polymer–modified bitumen (PMB). A novel High–Modulus Polyurethane Prepolymer (HM–PU) bitumen modifier was independently prepared to explore its modification effect and optimal application parameters. Experimental results show that the optimal isocyanate group (NCO) content and dosage of the HM–PU modifier are both 5%. The thermal stability and high– and low–temperature performance of modified bitumen are significantly enhanced, and HM–PU exhibits excellent compatibility with base bitumen (BA). This work innovatively synthesizes the HM–PU modifier and clarifies its physicochemical modification mechanism via macroscopic performance tests, thermal analysis, and microscopic characterization, providing a new strategy for the development and application of eco–friendly bitumen modifiers. Full article

The development of lightweight aluminum matrix composites with improved mechanical performance and thermal stability using sustainable reinforcement materials remains a significant challenge in structural materials engineering. Although ceramic-reinforced aluminum composites exhibit enhanced strength and thermal resistance, the potential of bio-derived snail shell particles as environmentally sustainable reinforcements remains insufficiently explored. In this study, snail-shell-reinforced AA6061 aluminum matrix composites were fabricated by stir casting to investigate their microstructural characteristics, mechanical behavior, phase composition, and thermal stability. Snail shell particles, predominantly composed of CaCO₃, were processed to particle sizes of 50–75 µm before incorporation into the molten aluminum matrix. Characterization was performed using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), tensile and hardness testing, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results revealed relatively uniform particle dispersion and satisfactory matrix–reinforcement interfacial compatibility. The tensile strength increased from 155 ± 5 MPa for the unreinforced alloy to 211 ± 4.8 MPa for the reinforced composite, corresponding to an improvement of approximately 36%, while elongation increased from 2.4 ± 0.2% to 4.6 ± 0.4% (92%). XRD analysis confirmed the presence of Al, CaCO₃, Mg₂Si, and minor CaO phases, indicating successful reinforcement incorporation and strengthening phase formation. Thermal analysis demonstrated enhanced thermal stability, increased residual mass retention, and improved resistance to thermal degradation. This work demonstrates that bio-derived snail shell particles are viable and environmentally sustainable reinforcements for lightweight aluminum matrix composites intended for structural engineering applications. Full article

Ambient-temperature asphalt binders have emerged as a sustainable alternative to traditional hot-mix asphalt, offering significant advantages in energy conservation and emission reduction. This review systematically examines the research progress and development trends of high-performance reactive asphalt binders designed for ambient-temperature application, which achieve enhanced performance through chemical cross-linking reactions. The study focuses on three core material systems: epoxy resin, waterborne epoxy emulsified asphalt, and polyurethane. For each system, we comprehensively summarize the material composition, strength formation mechanisms, and mix design methodologies. Key evaluation methods for critical pavement performance—including strength characteristics, water stability, and high-temperature performance—are critically reviewed. Furthermore, microscopic characterization techniques including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) are discussed to elucidate the underlying mechanisms governing performance evolution. Analysis reveals that epoxy-based binders exhibit superior strength and stiffness, rendering them suitable for heavy-traffic pavements; waterborne epoxy emulsified asphalt binders combine environmental compatibility with construction convenience for thin-layer rehabilitation, while polyurethane-based binders demonstrate exceptional elasticity and rapid curing characteristics for quick-traffic-opening scenarios. Although current research has established a preliminary performance evaluation framework, the absence of unified technical standards constrains widespread engineering implementation. Future research priorities should focus on developing water-triggered curing systems, intelligent responsive materials, and comprehensive standardization systems to fully harness the engineering potential of these sustainable binders. Full article

Silicon carbide–aluminum (SiC–Al) composites offer high hardness, wear resistance, thermal stability, and strength-to-weight ratio, making them suitable for advanced engineering applications. Fabricating these composites via powder metallurgy and infiltration methods has been reported. However, there is no reported study on fabricating SiC–Al composites using binder jetting additive manufacturing (BJAM) followed by sintering without infiltration. The present study aims to fill this gap. In this study, samples were printed by BJAM using SiC–Al mixed powders with two volumetric ratios (SiC:Al) of 60:40 and 80:20, respectively. These printed samples were then sintered at different temperatures (950 °C, 1200 °C, and 1400 °C). The results show that, using this new approach, the printed green samples retained structural integrity after sintering and that interparticle bonding was achieved. To the authors’ knowledge, this is the first study to fabricate a SiC–Al composite via binder jetting additive manufacturing using a mixed powder, followed by sintering without infiltration. Full article

This study investigates the effect of waste cement dust (CD) and rock wool (RW) inorganic fiber on the tribological performance of brake friction composite materials. Five formulations were fabricated by varying CD from 65 to 45 wt.% and RW from 5 to 25 wt.% and evaluated for tribological properties on a Chase friction testing machine in accordance with IS 2742 test procedures. The results show that composites containing higher CD and lower RW exhibited higher coefficients of friction, lower friction variability, and improved fade resistance. In contrast, composites containing higher RW and lower CD showed improved recovery characteristics and substantially enhanced wear resistance. The performance coefficient of friction decreased from about 0.521 to 0.442 as the formulation shifted from CD-rich to RW-rich compositions, while the variability coefficient increased from about 0.364 to 0.516. The highest wear was recorded for the composite containing 65 wt.% CD and 5 wt.% RW inorganic fiber, whereas the lowest friction fluctuations were obtained for the composite containing 55 wt.% CD and 15 wt.% RW inorganic fiber. Finally, a simple ranking process-based decision-making technique was employed to evaluate the overall performance of all the composites, suggesting 55 wt.% CD as the optimal content. These findings confirm the potential of waste CD as a viable functional constituent in brake friction composites when combined with RW inorganic fiber in an optimized manner. Full article

Infrastructure expansion in Indonesia has increased demand for paving blocks, raising concerns over cement production costs and environmental impact. This study investigates the comparative effectiveness of pineapple leaf fiber (PALF, Ananas comosus) and sisal fiber (Agave sisalana) as reinforcements in paving blocks, evaluating water absorption and 28-day compressive strength at fiber contents of 0%, 1%, 3%, 5%, and 7% by cement volume. A full-factorial two-way ANOVA with post-hoc Tukey HSD was employed. A dosage of 3% for both fiber types resulted in compressive strengths of 14.5 MPa (PALF, +59% vs. control) and 15.2 MPa (sisal, +67% vs. control), both of which met the requirements of SNI 03-0691-1996 Class B. Sisal fiber demonstrated superior compressive performance, consistent with its higher stiffness and tensile strength as reported in the literature. Water absorption increased monotonically with fiber content for both types, with SNI Class D compliance (≤10%) maintained only at 0% for PALF and 0–1% for sisal, a known consequence of the inherently hydrophilic nature of plant-based natural fibers. A statistically significant interaction term (F = 3.697, p = 0.012) confirmed that the two fibers respond differently to dosage increases, providing nuanced practical guidance beyond what single-factor studies can offer. These findings demonstrate the promising compressive strength of agricultural waste fiber-reinforced paving blocks, warranting further investigation of abrasion resistance, flexural strength, and long-term durability before practical deployment. Such utilization supports circular economy principles in the construction industry. Full article

This study analyzed the initial adsorption and activation of CO₂ on bimetallic Cu_nSc nanoclusters, with n = 3–7, using DFT calculations in ORCA with the r²SCAN-3c method. A total of 20 bare clusters and their corresponding Cu_nSc–CO₂ complexes were investigated, considering four structural configurations for each composition. To avoid classification based solely on adsorption energy, a global CO₂ activation index was developed and defined as IACO₂ = z(AG) + z(CTCO₂) + z(Bending) + z(ΔrC–O). In this index, AG = −ΔG_ads, CT_CO2 = −qCO₂, bending corresponds to (180° − ∠O–C–O), and (ΔrC–O) represents the average elongation of the C–O bonds. This descriptor enabled distinguishing complexes that only stabilize CO₂ from those that induce effective geometric and electronic activation. Although 5IV and 3IV exhibited favorable adsorption, with (ΔG_ads) values of −52.978 and −53.494 kcal mol⁻¹, respectively, their molecular activation was low, with nearly linear CO₂ and minimal or unfavorable charge transfer. In contrast, 7III and 7II showed the highest activation, with CT_CO2 values of 1.206 and 1.163, bending values of 69.867° and 68.869°, and C–O elongations of 0.208 and 0.195 Å, respectively. The standardized (IACO₂) ranking identified 7III, 7II, 3III, and 3II as the most relevant systems, with scores of 100.0, 93.8, 88.2, and 86.8, respectively. These results show that CO₂ activation on Cu_nSc nanoclusters should not be assessed solely by (ΔG_ads), but rather by a multi-criteria approach that accounts for stability, charge transfer, and molecular distortion. Full article

Graphene-reinforced aluminum-based materials perfectly combine the excellent properties of graphene and aluminum, achieving superior lightweight structural characteristics. This study focuses on 1:2 internal resonance, analyzing the amplitude–frequency and force–amplitude responses of a graphene-platelet-reinforced aluminum-based truncated conical shell under multiple external excitations. Considering three different graphene distributions, an improved Halpin–Tsai mechanical model is used to predict the effective Young’s modulus of the GPL-enhanced aluminum-based truncated conical shell. Under temperature effects, based on the Reissner–Mindlin theory and von-Karman geometric nonlinear strain–displacement relationships, Hamilton’s principle and the Galerkin method are employed to derive the motion equations of the GPL-enhanced aluminum-based truncated conical shell. Through multiscale perturbation analysis, the averaged equations in polar coordinates are further derived. Based on the combined averaged equations, the amplitude–frequency and force–amplitude response curves of the system are plotted, investigating the influence of graphene distribution, graphene content, external excitation amplitude, tuning parameters, and graphene plate geometrical dimensions on its vibration characteristics. The analysis results indicate that graphene content is one of the primary factors affecting the vibration characteristics of graphene-reinforced aluminum-based truncated cones. Full article

Pultrusion is an efficient continuous manufacturing process for fiber-reinforced polymer (FRP) composites, but conventional open-bath impregnation has limitations such as resin exposure, quality variation, and resin loss. To overcome these limitations, closed-injection pultrusion (CIP) and short-pot-life resin systems have recently been introduced. However, the effects of processing variables on the quality and properties of composites manufactured using such resin systems have not been fully clarified. In this study, the effects of resin viscosity and pulling speed on the quality and mechanical properties of carbon FRP (CFRP) and glass FRP (GFRP) composites manufactured by CIP were investigated. CFRP and GFRP composites were fabricated at resin temperatures of 30 and 40 °C and pulling speeds of 300, 400, and 500 mm/min. The manufactured composites were evaluated in terms of void content, microstructure, hardness, and tensile properties. The results showed that increasing pulling speed increased void content and promoted macrovoids and locally poor impregnation, whereas the influence of resin temperature was relatively limited. Hardness, tensile strength, and elastic modulus decreased as pulling speed increased. These results demonstrate that CFRP and GFRP composites can be successfully manufactured by CIP using short-pot-life resin systems, and that precise control of resin viscosity and pulling speed is essential for achieving high quality and mechanical performance. Full article

Cementitious materials are naturally brittle, which makes them prone to cracking. This study effectively employs autogenous healing techniques using microcapsules to solve this issue. The goals were twofold: first, to microencapsulate isophorone diisocyanate (IPDI) as a catalyst-free healing agent; and second, to evaluate how these microcapsules improve the healing abilities of cementitious materials. Polyurethane (PU) prepolymer with an NCO content of 19.8% was successfully created. Using interfacial polymerization, smooth, spherical microcapsules of IPDI with an average diameter of 38 to 62 micrometers were produced. The elastic modulus of the microcapsules ranged from 0.23 to 0.18 GPa, while their hardness varied between 5.29 and 4.15 MPa. Over six months, the microcapsules showed a weight loss of 9.72% to 12.47%, depending on their size, under ambient conditions. Specimens containing 3% of fabricated microcapsules demonstrated the ability to seal cracks less than 100 µm wide by up to 70%. Specimens that incorporated 3% of their cement weight in IPDI microcapsules achieved an impressive 74% recovery rate in compressive strength. In contrast, control mortars without microcapsules showed a recovery rate of less than 50%. Analysis using Energy Dispersive Spectroscopy (EDS) revealed a significant presence of carbon in areas where the microcapsules had ruptured and the cracks had healed. This confirms the effectiveness of the healing process, consistent with established self-healing theories. The water tightness recovery trace showed a recovery rate of up to 61%. Additionally, the specimens containing microcapsules exhibited higher initial compressive strength than the control specimens. However, this also indicates that some microcapsules may have ruptured unintentionally during preparation and molding. Therefore, further research on the mechanical properties of microcapsules, especially their stiffness in cementitious composites, is necessary. Full article

Moisture-induced damage is one of the primary causes of premature distress in asphalt pavements, leading to reduced service life and increased maintenance costs. Although nanomaterials have shown potential in enhancing asphalt performance, the underlying composite interaction mechanisms among nanomaterials, asphalt binder, and aggregate phases under moisture exposure are still not fully understood. In addition, comparative evaluations under consistent experimental conditions remain limited. This study investigates the influence of five nanomaterials: nano-silica (NS), nano-alumina (NA), nano-titanium dioxide (NT), nano-zinc oxide (NZ), and carbon nanotubes (CNT) on the physical and mechanical properties of asphalt binders and mixtures, with particular emphasis on moisture damage resistance. The nanomaterials were incorporated at dosages of 1.5%, 3.0%, 4.5%, and 6.0% by binder weight. Binder performance was evaluated using conventional and performance grading (PG) tests, while mixture performance was assessed through Marshall properties and moisture susceptibility indicators, including the tensile strength ratio (TSR) and the index of retained strength (IRS). Fluorescence microscopy (FM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were employed to investigate nanomaterial dispersion characteristics, microstructural morphology, and physicochemical interactions within the asphalt composite system. The results indicate that nanomaterial modification reduced penetration and increased softening point and Marshall stability, reflecting enhanced stiffness and thermal resistance, although ductility decreased at higher dosages. Significant improvements in moisture resistance were observed, particularly under conditioned states. The TSR increased from 81.2% for the control mixture to 92.4% for NS and 91.7% for NA, while the IRS improved from 72.7% to 88.5% for NS. Statistical analysis indicated that both nanomaterial type and dosage significantly affected TSR and IRS performance, with dosage exhibiting comparatively greater influence on moisture resistance improvement. FM and SEM analyses revealed comparatively better dispersion and lower agglomeration tendency for NS and NA, which corresponded to their superior moisture resistance performance. FTIR analysis indicated that the modification process was predominantly physical, with no major formation of new chemical functional groups. Among the investigated nano materials, NS at 6% dosage exhibited the most pronounced improvement, followed by NA at similar dosage levels. Overall, the findings suggest that nanomaterial modification can considerably improve the moisture resistance and mechanical performance of asphalt mixtures under laboratory conditions. However, higher nanomaterial dosages may adversely affect binder workability due to increased viscosity, particularly in CNT-modified binders. Full article

Steel–concrete composite beams are widely used in bridge infrastructure but are vulnerable to deterioration due to uniform and pitting corrosion, particularly at the lower flange. This study investigates the flexural behavior of corroded steel–normal strength concrete (NSC) composite beams and evaluates rehabilitation using ultra-high-performance concrete (UHPC) slab replacement, with and without additional steel plate strengthening. A comprehensive finite element analysis was conducted considering three beam spans (5, 7, and 9 m), two corrosion types, and three corrosion levels. The results indicate that both corrosion types significantly reduce flexural capacity due to cross-sectional loss, with pitting corrosion causing greater strength reduction than uniform corrosion at the same weight loss because of stress concentration effects. Replacing the NSC slab with a UHPC slab effectively restores and often enhances load-carrying capacity beyond that of intact beams while reducing dead load, demonstrating the superiority of the proposed rehabilitation approach. The combined use of UHPC slab replacement and welded steel plate strengthening provides the greatest improvement, revealing a strong synergistic effect. A case study of a corroded steel bridge in Pennsylvania confirms the practical applicability of the method, showing that UHPC-based rehabilitation increases the load rating from below unity to above unity. These findings highlight UHPC as an efficient and sustainable solution for extending the service life of aging steel bridges. Full article

High-performance and ultra-high-performance fiber-reinforced concretes (HPFRC/UHPFRC) have emerged as advanced cementitious composites capable of achieving superior mechanical performance, durability, and structural efficiency compared with conventional concrete. However, their widespread adoption remains challenged by relatively high material costs and significant embodied environmental impacts associated with elevated binder and fiber contents. This study presents a comprehensive life-cycle review of advanced high-performance cementitious composites, evaluating their sustainability from raw material extraction and mix design to structural application, service life, and end-of-life considerations. The review synthesizes current knowledge on material composition, production processes, structural performance, durability characteristics, and environmental impacts through the framework of life-cycle assessment (LCA). Particular attention is given to the influence of mix-design parameters, including binder composition, supplementary cementitious materials (SCMs), aggregate systems, and fiber type, on embodied carbon, energy demand, and mechanical performance. A dataset compiled from published experimental studies covering high-performance and ultra-high-performance concrete mixtures is analyzed to examine relationships between compressive strength, embodied energy, and carbon footprint, highlighting the dominant role of cementitious binders and fiber production in environmental impacts. Although advanced fiber-reinforced concretes generally exhibit higher cradle-to-gate emissions than conventional concrete, their superior mechanical properties, improved durability, reduced material demand, and extended service life can substantially reduce life-cycle environmental impacts at the structural level. The review further discusses emerging strategies for developing low-carbon high-performance cementitious composites, including clinker reduction, recycled and alternative fibers, optimized particle packing, and AI-assisted mix design. Finally, key research gaps are identified, particularly regarding standardized LCA methodologies, long-term durability data, harmonized performance-based functional units, and circular-economy strategies for material recycling and reuse. The findings highlight that performance-based life-cycle evaluation is essential for accurately assessing the sustainability potential of advanced high-performance cementitious composites in resilient and low-carbon infrastructure systems. Full article

Thin-walled composite beams with unsymmetric laminates are attracting increasing attention in lightweight aerospace and mechanical structures because they enable enhanced stiffness tailoring and weight reduction beyond the limitations of conventional symmetric stacking sequences. However, despite their practical relevance, unsymmetric thin-walled laminates have received comparatively limited attention in the available buckling literature due to the additional complexity introduced by membrane–bending coupling effects. This study presents an efficient and physically transparent formulation for the buckling analysis of thin-walled composite beams with both symmetric and unsymmetric layups by combining Generalized Beam Theory (GBT) with the Ritz method. The proposed GBT-Ritz framework captures global, local, distortional, torsional, and shear-related deformation modes while consistently incorporating laminate coupling effects associated with unsymmetric configurations. The formulation is applicable to open, closed, branched, and unbranched cross-sections commonly encountered in aerospace structures. Validation against ABAQUS V2017 shell finite element models demonstrates excellent agreement (with discrepancies generally below 6%) in predicting critical buckling loads and mode shapes for various geometries and boundary conditions. The results show that unsymmetric laminates can significantly influence buckling behavior, particularly in open sections and intermediate beam lengths where coupling effects become dominant. Compared with conventional finite element approaches, the proposed method achieves substantially lower computational cost (providing speed-up factors of 1.5 to 2.5) while preserving clear physical insight into interacting instability mechanisms. Overall, the developed framework provides an efficient and practically relevant tool for the analysis and design of advanced thin-walled composite structures with tailored unsymmetric laminates. Full article

Adequate polymerization of resin-based composites is essential for marginal sealing and mechanical performance. This study evaluated the effects of different light-curing protocols on gingival microleakage and microhardness of a high-viscosity bulk-fill composite, Filtek™ One Bulk Fill Restorative (3M ESPE; AUDMA, AFM, UDMA, 1,12-dodecane-DMA; silica/zirconia fillers, 76.5 wt%, 58.4 vol%) and conventional nanohybrid composite, Filtek™ Z250 XT Universal Restorative (3M ESPE; Bis-EMA, UDMA; zirconia/silica fillers, 82 wt%, 68 vol%). Forty-eight extracted human second premolars and 48 cylindrical specimens were used for microleakage and Vickers microhardness testing, respectively. Specimens were cured using an O-Star LED unit in turbo mode (2700–3000 mW/cm², 3 s) or soft-start mode (0–1200 mW/cm², 20 s) at 2 mm and 5 mm distances. Data were analyzed using Kruskal–Wallis and Dunn’s tests (p < 0.05). Significant differences were found among groups. Soft-start curing at 2 mm produced the lowest microleakage, whereas turbo curing at 5 mm produced the highest. The conventional composite exhibited higher top and bottom microhardness values. Bottom-to-top hardness ratios were below 80% in most groups, except for the conventional composite cured with soft-start mode. Based on our findings, soft-start curing at short distances provides favorable outcomes, while turbo curing at 5 mm is not recommended. Full article

This study investigates the effect of mineral additives of different natures, namely blast-furnace slag, fly ash, and bentonite, on structure formation, phase composition, microstructure, and physicomechanical properties of cement matrices. The analysis included measurements of mass change and linear shrinkage during hardening, determination of density and microhardness, X-ray phase analysis, and microstructural examination by scanning electron microscopy. It was found that the introduction of mineral additives reduced linear shrinkage from 6.06 mm for the control composition to 0.25 mm for the composition with blast-furnace slag, 2.31 mm for the composition with fly ash, and 1.01 mm for the composition with bentonite. The maximum density and microhardness values were obtained for the matrix with blast-furnace slag and amounted to 1.99 ± 0.03 g/cm³ and 39.95 ± 1.12 HV1, respectively, whereas the overall range of values for the investigated compositions was 1.52–1.99 g/cm³ and 30.2–39.95 HV1. X-ray phase analysis showed that the amorphous component varied from 61 to 78%, reaching its maximum value in the composition with blast-furnace slag, which is associated with the formation of poorly crystalline C–S–H and aluminosilicate phases. According to the SEM data, the average size of visible pore-like defects was 2.4 μm for the control composition, 1.4 μm for the composition with blast-furnace slag, 1.3 μm for the composition with fly ash, and 1.7 μm for the composition with bentonite. The most favorable combination of high density, microhardness, developed amorphous component, and homogeneous microstructure was established for the composition with blast-furnace slag. The obtained results can be used as a materials-science basis for the development of cement matrices intended for further studies on the immobilization of solid radioactive waste. Full article

The growing demand for sustainable materials as alternatives to conventional petroleum-based plastics has accelerated research on alginate-based films. Alginate is a naturally occurring polysaccharide, mainly extracted from brown algae and widely used in the bioindustry due to its biodegradability, film-forming ability, biocompatibility, and functional versatility. However, a comprehensive understanding of global research trends and emerging directions in this field remains limited. This study presents a bibliometric analysis of global research on alginate-based films from 2001 to December 2024, aiming to identify key trends, collaboration patterns, thematic structures, and future directions. The dataset was retrieved from Scopus and analyzed using VOSviewer (v.1.6.20). A significant increase in publications has been observed over the past five years. The International Journal of Biological Macromolecules was identified as the leading journal. “Agricultural and Biological Sciences” dominated the field. China was the most productive country, while Jhong-Whan Rhim was the most prolific author. Jiangnan University was the most active institution. Keyword analysis revealed three themes: mechanical enhancement, food packaging, and biomedical applications. Recent trends indicate a growing focus on sustainable food packaging development. Full article

Lithium-ion batteries require cathode materials with high capacity and cycling stability. Li₃V₂(PO₄)₃ (LVP) offers a theoretical capacity of 197 mAh/g but suffers from poor electronic conductivity. In this study, a Li₃V₂(PO₄)₃/carbon (LVP/C) composite was synthesized via a citric acid-assisted sol–gel method. The effects of pyrolysis temperature (700–1000 °C) and citric acid-to-salt ratio (1:1, 0.5:1, 0.25:1) were systematically investigated. The optimal composite was obtained at 900 °C with a 1:1 ratio. This material exhibited a well-crystallized monoclinic structure (space group P2₁/c) with unit cell volume of 890.61 ų. The amorphous carbon coating provided a specific surface area of 33.03 m²/g. Electrochemically, the optimal LVP/C_1:1 composite delivered an initial specific capacity of 114 mAh/g at C/10 rate—twice that of samples with lower carbon content. It also demonstrated 100% capacity retention after 25 cycles with favorable coulombic efficiency (67%) and reduced charge-transfer resistance. These results show that pyrolysis at 900 °C with a 1:1 citric acid-to-salt ratio provides an optimal balance between crystallinity, carbon coating uniformity, and electrochemical performance for high-performance LVP/C composite cathodes. Full article

The study presents an approach to the synthesis of micro- and nano-sized biosilica from rice husk ash (RHA) and describes its effective incorporation into cementitious composites for 3D concrete printing (3DCP). It is demonstrated that the calcination of rice husk at 700 °C, followed by sonochemical treatment, leads to the formation of a nanoscale silica phase with high pozzolanic reactivity. X-ray powder diffraction (XRD), infrared spectroscopy (IR), differential thermogravimetric analysis (DTG), and scanning electron microscopy (SEM) show that the incorporation of nano-biosilica (NBS) into the cementitious composites accelerates the hydration process through a nucleation effect and pozzolanic reaction. This, in turn, densifies the hardened cement microstructure and improves compressive strength significantly. Laboratory 3D concrete printing tests demonstrate that adding 1.72 wt.% NBS improves shape retention, decreases layer slump, and improves interlayer bond strength. The results indicate the viability of rice husk ash-derived biosilica as a supplementary cementitious material (SCM) in 3DCP due to its positive influence on the concrete mortar properties and parameters. Full article

Unsaturated polyester (UP) composites are widely utilized in engineering applications, including vehicle body structures, due to their ease of processing and good interfacial compatibility with natural fibers. However, the inherent brittleness of UP limits its performance under impact or tensile loading, as it exhibits minimal plastic deformation and is prone to crack initiation and propagation. In this study, bamboo fiber was incorporated into the UP matrix at various mixing ratios to enhance its crack resistance. After achieving uniform dispersion, the composites were subjected to a splitting tensile test to evaluate their crack resistance behavior. The results indicate that the composite containing 80% polyester exhibits the highest fracture toughness, with a crack resistance value of K_1C = 1.396 MPa·m^0.5. This value represents a 192.03% improvement compared with neat polyester (K_1C = 0.713 MPa·m^0.5). The enhanced crack resistance is attributed to the fiber bridging and energy-absorption mechanisms introduced by the bamboo fibers. These findings demonstrate the effectiveness of bamboo fiber reinforcement in improving the fracture performance of UP-based composites, highlighting their potential for use in lightweight structural applications. Full article

Cellulosic fibers can impart many unique benefits into composite applications, such as reduced weight or structural reinforcement; however, these materials also increase hygroscopicity and decrease thermal stability, restricting broader applications. The present work adapted an experimental process for functionalizing the cellulose surface using citric acid (CA) for three fibers: a 100% cellulose bleached soft Kraft pulp (e.g., creafill) and two natural fibers with similar composition but different fiber morphology, flax fiber and banana fiber. The process uses CA with a sodium hypophosphite (SHP) catalyst to chemically functionalize fiber surfaces, and the reaction mechanism was investigated through Fourier Transform Infrared Spectroscopy (FTIR), which suggested a grafting mechanism rather than a surface-based crosslinking between neighboring sites. Functionalized fibers were compounded into polylactic acid (PLA) at 20 wt.% to better understand how this functionalization might impact critical performance properties like thermal stability, crystallization, thermal mechanical properties, and water uptake of these composites. The study demonstrated varying levels of efficacy for the functionalization of cellulosic fibers with CA/SHP and the fiber with the most open microstructure, e.g., banana fiber, exhibited the largest change in its properties with a 38% reduction in water uptake compared to untreated banana fiber composites. Parallel evaluation of the functionalization process for different fibers demonstrates the importance of fiber morphology on surface modification and can enable their use in composites by demonstrating the efficacy of this potentially low-cost, low-toxicity method for reducing hygroscopicity and improving thermal stability. Full article