Search Results (235)

This study evaluates the performance of single concrete-filled frictional Fibre-Reinforced Polymer (FRP) piles embedded in saturated liquefiable sand and subjected to seismic loading using a shaking table. A unidirectional shaking table equipped with a 1000 mm × 1000 mm × 1000 mm laminar shear box with 27 lamina rings was utilized in the study. FRP tubes manufactured from epoxy-saturated Carbon Fibre-Reinforced Polymer (CFRP) and Glass Fibre-Reinforced Polymer (GFRP) fabrics were filled with 35 MPa concrete and allowed to cure for 28 days, serving as model piles for the experimental programme, with cylindrical concrete prisms employed to represent the behaviour of traditional piles. Pile dimensions and properties based on scaling relationships were selected to account for the nonlinear nature of soil–pile systems under seismic loading. Scaled versions of ground motions from the 2010 Val-des-Bois and 1995 Hyogo-Ken Nambu earthquakes were implemented as input motions in the tests. The results show limited variation in the inertial and kinematic responses of the piles, especially before liquefaction. Head rocking displacements were within 5% of each other during liquefaction. Post liquefaction, the concrete-filled FRP piles showed lower response compared to the traditional concrete pile. The results suggests that concrete-filled FRP piles, especially those made from carbon fibre, provide practical alternatives for use. Full article

In this article, the thermal and mechanical properties of mortars reinforced with polypropylene (PP) fibres have been studied. Particularly, the effect of polypropylene fibres’ addition on the thermal behaviour of fine-grained building mortars at high temperatures was studied using simultaneous thermal analysis. Two types of polypropylene fibres, differing in shape and size, were used as fillers. The thermal behaviour of cement mortar samples with and without fibres was described. Special attention was given to the thermal behaviour of fibre-reinforced cement mortars subjected to the high temperatures of 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, and 600 °C. Comparative studies using simultaneous thermal analysis (STA) were also performed for non-heated samples (20 °C). The TG, DTG, and DTA curves were analysed to investigate the effects related to the dehydration and the decomposition of hydration and carbonation products. Compared to mortar samples without fibres, the results showed that the presence of polypropylene fibres contributes to an increase in the thermal stability of the samples. It has been proven that the impact of the type and amount of PP fibres in the tested range (1.8 kg/m³ vs. 3.6 kg/m³) on the thermal stability of specimens of tested cement composites was found not to be significantly visible. Next, extensive research was performed on the impact of fire environmental exposure on the variability in the strength parameters of the mortars. Tensile strength tests were conducted based on the standards specified by the Polish Committee for Standardization. The research material consisted of high-strength, fine-grained building mortars, modified by an original method with polypropylene fibres at concentration of 1.8 kg/m³, 3.0 kg/m³, and 3.6 kg/m³. For reference, ordinary mortars without fibres were used, as well. Tensile strength was evaluated for mortar samples, which were exposed to temperatures of 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, and 600 °C, respectively. Special attention was paid to the thermal behaviour of cement mortars reinforced with polypropylene (PP) fibres, subjected to high temperatures. Based on the obtained test results, a detailed statistical analysis was developed, along with comprehensive temperature–parameter relationships, which could enable an approximate post-failure assessment of the mortar’s condition. The main outcomes of this paper include optimal fibre dosage, which is 3.6 kg/m³, identified optimal fibre type, namely F fibre, as well as plateau in tensile strength for temperatures between 200 °C and 400 °C for fibre-reinforced samples. Full article

Background: Acute coronary syndrome (ACS) encompasses ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, and unstable angina. While optimal medical therapy (OMT) is central to secondary prevention, lifestyle interventions—particularly dietary modification—remain underutilised despite their potential impact on long-term outcomes. Objective: To review the current evidence regarding dietary interventions post-ACS, their implementation, adherence, and effects on cardiovascular risk factors and clinical outcomes. Methods: A narrative literature review was performed using PubMed, including studies published in English from 2000 onwards. Keywords included “acute coronary syndrome,” “diet,” “cardiovascular disease,” “outcomes,” “adherence,” “wine,” and “intermittent fasting,” combined with Boolean operators AND/OR. Animal studies were excluded. The latest search was conducted in October 2025. Results: Mediterranean-style diets, when combined with OMT and lifestyle interventions (exercise, smoking cessation, alcohol moderation), consistently improve cardiovascular risk factors and reduce recurrent ischemic events and mortality. Clinical trials and cohort studies demonstrate long-term benefits, including reductions in all-cause mortality and major adverse cardiovascular events, particularly in patients adhering to structured dietary programmes within cardiac rehabilitation. Evidence for other dietary modifications, including low-fat diets, increased fibre, antioxidant supplementation, and intermittent fasting, was more limited, often derived from small or short-term studies focusing on surrogate endpoints. Real-world adherence to dietary guidelines remains suboptimal, especially in high-risk and obese populations. Preliminary studies suggest intermittent fasting and moderate red wine consumption may confer additional cardiovascular benefits, though larger, long-term trials are needed. Conclusions: Dietary modification is a key, yet underutilised component of secondary prevention post-ACS. A Mediterranean-style, whole-food diet integrated with OMT and supported by structured cardiac rehabilitation programmes offers the most evidence-based strategy to improve risk factor control and long-term outcomes. Future research should focus on pragmatic, long-term trials assessing hard cardiovascular endpoints and implementation strategies to enhance adherence across diverse populations. Full article

This article provides a multifaceted analysis of the feasibility, purposefulness, and legitimacy of the alternative use of industrial hemp (HF) fibres processed into fabrics and mats as multilayer reinforcement in polymer structural composites, potentially replacing glass fibres (GF) in various industries, including the production of recreational vessels (yachts and motorboats) and other floating products (buoys/floats/pontoons, etc.). Based on the results of physical, mechanical, and morphological tests of new polymer structural composites HFRP vs. GFRP and a comparative analysis of their properties, a structural correlation coefficient for HFRP was determined with respect to GFRP [W_K = 1.66 (6), provided that the grammage of reinforcement of the skin/shell of the selected floating object/structure is comparable]. This article presents the possibility of meeting stringent environmental protection requirements for the future safe recycling and/or disposal of products and their post-production waste manufactured from HFRP at the end of their service life. Fire tests of these new materials have shown that it is possible to use them completely (almost 100%) in the near future, mainly through energy recovery. Full article

This study situates washed sheep-wool fibres as a sustainable reinforcement candidate for epoxy matrices and evaluates their mechanical response under tensile, flexural, compressive, and Charpy impact loading. The objective of this work is to assess whether short, washed sheep-wool fibres can function as a sustainable reinforcement for epoxy matrices, and to identify optimal fibre length–content windows that improve mechanical behaviour for engineering applications. Moulded–machined specimens were produced with fibre lengths of 3, 6, and 10 mm and contents of 1.0–5.0 wt.%, depending on the test; neat epoxy served as the reference. In tension, selected formulations—particularly 10 mm/1.5 wt.%—showed simultaneous increases in ultimate stress and modulus relative to the neat resin, corresponding to gains of about 10% in ultimate tensile stress and 50% in tensile modulus, at the expense of ductility. In flexure, the modulus decreases by roughly 15–35% compared with the matrix, whereas configurations with 3–6 mm at 2.5–5 wt.% raise the fracture stress by about 35–45% and improve post-peak resistance. In compression, reinforcement markedly elevates yield stress, with increases of up to about 160% at 3 mm/2 wt.%, while the ultimate strain decreases moderately. In Charpy impact, all reinforced materials underperform the resin, with absorbed energy reduced by roughly 75–93% depending on fibre length and content, with 3 mm/1 wt.% being the least affected. A two-factor analysis of variance (ANOVA) indicates that fibre length primarily governs tensile and compressive behaviour, while fibre content dominates flexural and impact responses. Overall, the findings support wool fibres as a viable reinforcement when length and content are optimized, pointing to their use in non-structural to semi-structural industrial components such as interior panels, housings, casings, protective covers, and other parts where moderate tensile/compressive performance is sufficient and material sustainability is prioritised. Full article

This study aims to evaluate the influence of glass fibre (GF) type and content on the thermal, mechanical, and morphological properties of polyethylene terephthalate (PET)-based composites containing post-consumer PET flakes, intended for mouldings exposed to cementitious environments (e.g., anchors). Two chemically resistant GFs were compared: alkali-resistant (AR) fibres with soft sizing (SGFs) and electrical-/chemical-resistant (ECR) fibres with hard sizing (HGFs). Composites with fibre contents of 10–60 wt.% were prepared, with detailed analysis focused on 30 to 50 wt.%—the range typical for practical applications. AR fibres experienced greater shortening during processing, and their actual fibre content was lower than the intended value. Differential scanning calorimetry (DSC) revealed enhanced crystallisation kinetics for SGF composites, with higher crystallinity of the injection-moulded samples and elevated crystallisation temperatures (206–208 °C for SGF vs. 196–197 °C for HGF). Thermogravimetric analysis (TGA) indicated that thermal stability was primarily governed by fibre content; both SGF and HGF composites showed improved resistance compared to neat PET. Mechanical tests demonstrated that both fibre types effectively reinforced the matrix: HGF composites exhibited a higher elastic modulus (20.6 GPa for HGF-50 vs. 18.3 GPa for SGF-50), whereas SGF composites exhibited roughly 10–20% higher tensile, flexural, and impact strength, despite slightly lower fibre content. SEM analysis confirmed more uniform fibre distribution and fewer voids in SGF composites. These results highlight the importance of GF selection for PET composites in alkaline environments, taking into account the properties of the sizing film former and balancing trade-offs between mechanical performance, thermal stability, processability, and economic factors. Full article

The study aims to assess the potential of recycled carbon fibers recovered from end-of-life wind turbine blades as a sustainable reinforcement material for concrete and to establish correlations between fiber parameters and the mechanical behavior of fiber-reinforced concrete. The research focuses on how fiber length, content, and cement type affect the residual flexural strength and cracking behavior of FRC. The experimental program included 48 concrete mix series with varying fibre lengths (25, 38, and 50 mm), dosages (0, 2, 4, and 8 kg/m³), cement types (CEM I 42.5 and CEM II 42.5R/A-V), and water-to-cement ratios (0.50 and 0.40). Mechanical properties such as compressive strength, tensile strength, modulus of elasticity, and residual flexural strength were evaluated. Notched beams underwent three-point bending tests, and the progression of cracks was tracked using the digital image correlation method. The analysis revealed that enhancing both the fiber content and length generally bolstered the toughness and post-cracking characteristics of concrete, with a notable effect observed for fibers ranging from 38 to 50 mm in length when used at a dosage of 8 kg/m³. However, the effects depend on the fiber recovery technology and the base concrete strength, which may influence the results and should be considered as a limitation of this study. Full article

Collagen, as the predominant structural protein in vertebrates, represents a promising biomimetic material for scaffold development. Fibre-based scaffolds produced through textile technologies enable precise modulation of structural characteristics to closely mimic the extracellular matrix architecture using wet-spun collagen fibres. However, this in vitro fibre formation lacks natural crosslinking, resulting in collagen fibres with compromised mechanical strength, enzymatic resistance, and thermal stability compared to their native counterparts, thus restricting their biomedical applicability. Post-fabrication crosslinking is therefore imperative to enhance the durability and functional performance of collagen fibre-based scaffolds. Although traditional crosslinkers like glutaraldehyde effectively improve mechanical strength and stability, their clinical utility is hindered by cytotoxicity and associated adverse biological responses. Alternative synthetic crosslinking agents, such as hexamethylene diisocyanate, 1-Ethyl-3-(3’-dimethyl amino propyl) carbodiimide, and 1,4-Butanediol diglycidyl ether, have demonstrated superior cytocompatibility while effectively improving collagen fibre properties. Nonetheless, synthetic compounds may induce more pronounced foreign body reaction than natural agents, necessitating further investigation into their cytocompatibility across varying concentrations. In contrast, plant-based crosslinking offers a promising, cytocompatible alternative, significantly enhancing the thermal and mechanical stability of collagen fibres, provided that potential fibre discolouration is acceptable for intended biomedical applications. Full article

Deep retrofits are one of the few pathways to decarbonize the existing building stock while simultaneously improving climate resilience. These retrofits improve insulation, airtightness, and mechanical equipment efficiency. NRCan’s Prefabricated Exterior Energy Retrofit (PEER) project developed prefabricated building envelope retrofit solutions to enable net-zero performance. The PEER process was demonstrated on two different pilot projects completed between 2017 and 2023. In 2024, in partnership with industry partners, NRCan developed new low-carbon retrofit panel designs and completed a pilot project to evaluate their performance and better understand resiliency and occupant comfort post-retrofit. The Low-Carbon Climate-Resilient (LCCR) Living Lab pilot retrofit was completed in 2024 in Ottawa, Canada, using low-carbon PEER panels. This paper outlines the design and construction for the pilot, including panel designs, the retrofitting process, and post-retrofit building and envelope commissioning. The retrofitting process included the design and installation of new prefabricated exterior retrofitted panels for the walls and the roof. These panels were insulated with cellulose, wood fibre, hemp, and chopped straw. During construction, blower door testing and infrared imaging were conducted to identify air leakage paths and thermal bridges in the enclosure. The retrofit envelope thermal resistance is RSI 7.0 walls, RSI 10.5 roof, and an RSI 3.5 floor with 0.80 W/m²·K U-factor high-gain windows. The measured normalized leakage area @10Pa was 0.074 cm²/m². The net carbon stored during retrofitting was over 1480 kg CO₂. Monitoring equipment was placed within the LCCR to enable the validation of hygrothermal models for heat, air, and moisture transport, and energy, comfort, and climate resilience models. Full article

This study investigates the mechanical behaviour of timber–concrete composite (TCC) floor members with an innovative adhesive connection reinforced by granite chips, glass fibre yarn net in the epoxy adhesive layer, and polypropylene (PP) fibres in the concrete layer. Laboratory tests involved three groups of specimens subjected to three-point bending over a span of 500 mm with specimen lengths of 550 mm. Group A specimens exhibited crack initiation at approximately 8 kN and partial disintegration at an average load of 11.17 kN, with maximum vertical displacements ranging from 1.7 to 2.5 mm at 8 kN load, increasing rapidly to 4.3 to 5 mm post-cracking. The addition of reinforcing fibres decreased the brittleness of the adhesive connection and improved load-bearing capacity. Finite element modeling using the newly developed Verisim4D software (2025 v 0.6) and analytical micromechanics approaches demonstrated satisfactory accuracy in predicting the composite behavior. This research highlights the potential of reinforcing the adhesive layer and concrete with fibres to enhance the ductility and durability of TCC members under flexural loading. Full article

The purpose of this study was to obtain a holistic view of mechanically recycled cotton from denim fabrics and the repurposing and recycling methods for similar fibres. A pre-consumer denim and three types of post-consumer denims were shredded into new fibres, which were characterised with single-fibre tensile testing, SEM imaging and DSC analysis. The opened cotton fibres were then blended with primary cotton with varying ratios and spun into yarns of 40 tex with a ring spinning machine. A ratio of 75/25 of recycled fibres to virgin fibres was obtained, with promising tensile strength results. Further, the yarns were knitted into single jersey fabrics, and abrasion testing was performed to evaluate their wearing out. Best abrasion resistance was obtained for knits consisting of 100% virgin cotton fibres and the knits consisting of a blend of pre-consumer and virgin fibres. The results suggest the yarns made with mechanically opened fibres are suitable for single jersey knits. SEM and DSC confirm the input of mechanical recycling defines the output. Moreover, the SEM pictures indicate there is little to no damage to single fibres caused by mechanical shredding, causing no further barriers for secondary use as raw materials. Full article

Additively manufactured continuous fibre-reinforced polymers (CFRPs) offer promising mechanical properties for engineering applications, including aerospace and automotive load-bearing structures. However, challenges such as weak interlayer bonding and low strength compared to traditional composites remain. This paper presents an experimental investigation into the effects of nitrogen (N₂) purging during printing and thermal annealing after printing on the tensile performance of additively manufactured CFRPs. Tensile tests were conducted on Onyx specimens produced by material extrusion and reinforced with continuous carbon fibre filaments (CFF), glass fibre filaments (GFF), or Kevlar fibre filaments (KFF). Results showed that N₂-purging and post-annealing had different effects on the tensile properties of various CFRPs. Particularly, N₂-purging, post-annealing, and their combination enhanced both the Young’s modulus and ultimate tensile strength (UTS) of KFF/Onyx specimens. For GFF/Onyx specimens, both treatments had a minor effect on the Young’s modulus but enhanced UTS. CFF/Onyx specimens exhibited improved Young’s modulus with N₂-purging, while both treatments reduced UTS. The different response of the CFRPs was associated with diverse governing failure mechanisms, as proved by microstructural and fracture surface inspection. Additionally, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses also revealed the thermal behaviour and crystal structures that influence the mechanical properties of CFRPs. Full article

This study investigates the flexural performance, tensile splitting strength, and fracture behaviour of self-compacting concrete (SCC) reinforced with polypropylene (PP) and basalt (BF) fibres. A total of eleven SCC mixtures with varying fibre types and volume fractions (0.025–0.25%) were tested at 7 and 28 days. In this study, the term high-performance concrete (HPC) refers to SCC mixtures with a 28-day compressive strength exceeding 60 MPa, as commonly accepted in European standards and literature. The control SCC achieved 68.2 MPa at 28 days. While fibre addition enhanced the tensile and flexural properties, it reduced workability, demonstrating the trade-off between mechanical performance and flowability in high-performance SCC. The experimental results demonstrate that both fibre types improve the tensile behaviour of SCC, with distinct performance patterns. PP fibres, owing to their flexibility and crack-bridging capability, were particularly effective at early ages, enhancing the splitting tensile strength by up to 45% and flexural toughness by over 300% at an optimal dosage of 0.125%. In contrast, BF fibres significantly increased the 28-day toughness (up to 15.7 J) and post-cracking resistance due to their superior stiffness and bonding with the matrix. However, high fibre contents adversely affected workability, particularly in BF-reinforced mixes. The findings highlight a dosage-sensitive behaviour, with optimum performance observed at 0.05–0.125% for PP and 0.125–0.25% for BF. While PP fibres improve crack distribution and early-age ductility, BF fibres offer higher stiffness and energy absorption in post-peak regimes. Statistical analysis (ANOVA and Tukey’s test) confirmed significant differences in the mechanical performance among fibre-reinforced mixes. The study provides insights into selecting appropriate fibre types and dosages for SCC structural applications. Further research on hybrid fibre systems and long-term durability is recommended. The results contribute to sustainable concrete design by promoting enhanced performance with low-volume, non-metallic fibres. Full article

Legumes are vital sources of protein, dietary fibre and nutrients, making them crucial for global food security and sustainable agriculture. However, their widespread acceptance and consumption are often limited by undesirable sensory characteristics, such as “a beany flavour”, bitterness or variable textures. Addressing these challenges requires a comprehensive understanding of the complex molecular mechanisms governing appearance, aroma, taste, flavour, texture and palatability in legumes, aiming to enhance their sensory appeal. This review highlights the transformative power of multi-omics approaches in dissecting these intricate biological pathways and facilitating the targeted enhancement of legume sensory qualities. By integrating data from genomics, transcriptomics, proteomics and metabolomics, the genetic and biochemical networks that directly dictate sensory perception can be comprehensively unveiled. The insights gained from these integrated multi-omics studies are proving instrumental in developing strategies for sensory enhancement. They enable the identification of key biomarkers for desirable traits, facilitating more efficient marker-assisted selection (MAS) and genomic selection (GS) in breeding programs. Furthermore, a molecular understanding of sensory pathways opens avenues for precise gene editing (e.g., using CRISPR-Cas9) to modify specific genes, reduce off-flavour compounds or optimise texture. Beyond genetic improvements, multi-omics data also inform the optimisation of post-harvest handling and processing methods (e.g., germination and fermentation) to enhance desirable sensory profiles and mitigate undesirable ones. This holistic approach, spanning from the genetic blueprint to the final sensory experience, will accelerate the development of new legume cultivars and products with enhanced palatability, thereby fostering increased consumption and ultimately contributing to healthier diets and more resilient food systems worldwide. Full article

This study looks at the effect of surface conditioners hydrofluoric acid (HFA), Ytterbium fibre laser (YFL), and Hydroxyapatite nanoparticles (HANPs) on the surface roughness (Ra) and shear bond strength (SBS) of different viscosity resin cements to lithium disilicate glass ceramic (LDC). A total of 78 IPS Emax discs were prepared and categorized into groups based on conditioning methods. Group 1 HFA–Silane (S), Group 2: YFL-S, and Group 3: HANPs-S. A scanning electron microscope (n = 1) and profilometer (n = 5) were used on each conditioned group for the assessment of surface topography and Ra. A total of 20 LDC discs for each conditioned group were subsequently categorized into two subgroups based on the application of high- and low-viscosity dual-cured resin cement. SBS and failure mode were assessed. ANOVA and post hoc Tukey tests were employed to identify significant differences in Ra and SBS among different groups. LDC conditioned with HFA-S, HANPs-S, and YFL-S demonstrated comparable Ra scores (p > 0.05). Also, irrespective of the type of conditioning regime, the use of low-viscosity cement improves bond values when bonded to the LDC. LDC treated with YFL-S and HANPs-S can serve as an effective substitute for HFA-S in enhancing the Ra and surface characteristics of LDC. The low-viscosity resin cement demonstrated superior performance by achieving greater bond strength. Full article