You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.

Search for Articles:

Title / Keyword

Author / Affiliation / Email

Journal

Article Type

Advanced Search

Section

Special Issue

Volume

Issue

Number

Page

Logical OperatorOperator

Search Text

Search Type

The Mechanical Properties of Single-Retted Flax Fibers Measured Using Micro- and Nanomechanics
Predicting the Tensile Properties of Carbon FRCM Using a LASSO Model
Advanced Structural Technologies Implementation in Designing and Constructing RC Elements with C-FRP Bars, Protected Through SHM Assessment

Journal Description

Fibers

Fibers is an international, peer-reviewed, open access journal on fiber science, published monthly online by MDPI.

Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
High Visibility: indexed within Scopus, ESCI (Web of Science), PubAg, CAPlus / SciFinder, Inspec, and other databases.
Journal Rank: JCR - Q2 (Materials Science, Multidisciplinary) / CiteScore - Q1 (Civil and Structural Engineering)
Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 21.3 days after submission; acceptance to publication is undertaken in 4.8 days (median values for papers published in this journal in the second half of 2024).
Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.

Impact Factor: 4.0 (2023); 5-Year Impact Factor: 4.0 (2023)

Imprint Information Journal Flyer Open Access ISSN: 2079-6439

Latest Articles

16 pages, 1840 KiB

Open AccessArticle

Cotton Fiber Micronaire and Relations to Fiber HVI and AFIS Qualities Between Deltapine^® and PhytoGen Upland Varieties

by Yongliang Liu and Doug J. Hinchliffe

Fibers 2025, 13(4), 41; https://doi.org/10.3390/fib13040041 - 3 Apr 2025

Cotton micronaire (MIC) is an essential fiber quality index that characterizes both fiber maturity and fineness components. This study compared how MIC affects the fiber high volume instrument (HVI) and advanced fiber information system (AFIS) qualities between Deltapine^® and PhytoGen upland varieties. [...] Read more.

Cotton micronaire (MIC) is an essential fiber quality index that characterizes both fiber maturity and fineness components. This study compared how MIC affects the fiber high volume instrument (HVI) and advanced fiber information system (AFIS) qualities between Deltapine^® and PhytoGen upland varieties. There were noticeable differences among HVI and AFIS qualities from Deltapine^® fiber samples and PhytoGen samples, with significant differences om HVI strength and elongation. MIC development benefited fiber HVI strength enhancement and also HVI short fiber index (SFI), AFIS neps, AFIS short fiber contents, and AFIS immature fiber content (IFC) reduction, all of which were desired. Adversely, MIC evolution could cause undesired HVI Rd lowering, HVI +b boosting, and AFIS UQL(w), and a decrease in L5%(n) in fiber. Further, MIC values were not related with lint turnout, but they were positively and greatly correlated with algorithmic M_IR values of the attenuated total reflection in Fourier transform infrared (ATR FT-IR) spectra. The results demonstrated the applicability of the ATR FT-IR technique combined with the M_IR approach for rapid laboratory MIC assessment at early MIC testing in remote/breeding locations. Full article

► Show Figures

Figure 1

23 pages, 7172 KiB

Open AccessArticle

Properties of Medium-Density Fiberboards with Different Contents of Recycled Fibers and Urea–Formaldehyde Resin

by Viktor Savov, Petar Antov, Viktoria Dudeva and Christian Panchev

Fibers 2025, 13(4), 40; https://doi.org/10.3390/fib13040040 - 3 Apr 2025

Recycling wood-based panels is essential for promoting the cascading use of wood, advancing the transition to a circular economy, and maximizing the efficient use of natural resources. While recycling particleboard has become a well-established industrial practice, recycling medium density fiberboard (MDF) panels presents [...] Read more.

Recycling wood-based panels is essential for promoting the cascading use of wood, advancing the transition to a circular economy, and maximizing the efficient use of natural resources. While recycling particleboard has become a well-established industrial practice, recycling medium density fiberboard (MDF) panels presents challenges, particularly in preserving material quality. The aim of this research work was to investigate and evaluate the combined effect of recycled MDF fibers and urea–formaldehyde (UF) resin content on the performance characteristics of the panels. MDF recycling was conducted using hydrothermal hydrolysis and hammer mill refinement. Preliminary experiments revealed that the degradation of properties in recycled MDF panels is not uniform with the addition of recycled fibers. The panels retained their properties significantly with up to 20% recycled fiber content, while formaldehyde emissions decreased by 1.2%. Based on these findings, the optimization of recycled fiber and UF resin content was performed, revealing that the maximum allowable recycled fiber content through hydrothermal hydrolysis and hammer mill refinement is 24%, with a minimum UF resin content of 12%. This study highlights the potential for integrating recycled MDF fibers into new panels, contributing to more sustainable production practices. By optimizing the balance between recycled fiber content and UF resin, it is possible to produce MDF panels that meet industry standards while reducing the environmental impact. Full article

► Show Figures

Figure 1

17 pages, 2840 KiB

Open AccessArticle

Fiber/Free-Space Optics with Open Radio Access Networks Supplements the Coverage of Millimeter-Wave Beamforming for Future 5G and 6G Communication

by Cheng-Kai Yao, Hsin-Piao Lin, Chiun-Lang Cheng, Ming-An Chung, Yu-Shian Lin, Wen-Bo Wu, Chun-Wei Chiang and Peng-Chun Peng

Fibers 2025, 13(4), 39; https://doi.org/10.3390/fib13040039 - 2 Apr 2025

Conceptually, this paper aims to help reduce the communication blind spots originating from the design of millimeter-wave (mmW) beamforming by deploying radio units of an open radio access network (O-RAN) with free-space optics (FSOs) as the backhaul and the fiber-optic link as the [...] Read more.

Conceptually, this paper aims to help reduce the communication blind spots originating from the design of millimeter-wave (mmW) beamforming by deploying radio units of an open radio access network (O-RAN) with free-space optics (FSOs) as the backhaul and the fiber-optic link as the fronthaul. At frequencies exceeding 24 GHz, the transmission reach of 5G/6G beamforming is limited to a few hundred meters, and the periphery area of the sector operational range of beamforming introduces a communication blind spot. Using FSOs as the backhaul and a fiber-optic link as the fronthaul, O-RAN empowers the radio unit to extend over greater distances to supplement the communication range that mmW beamforming cannot adequately cover. Notably, O-RAN is a prime example of next-generation wireless networks renowned for their adaptability and open architecture to enhance the cost-effectiveness of this integration. A 200 meter-long FSO link for backhaul and a fiber-optic link of up to 10 km for fronthaul were erected, thereby enabling the reach of communication services from urban centers to suburban and remote rural areas. Furthermore, in the context of beamforming, reinforcement learning (RL) was employed to optimize the error vector magnitude (EVM) by dynamically adjusting the beamforming phase based on the communication user’s location. In summary, the integration of RL-based mmW beamforming with the proposed O-RAN communication setup is operational. It lends scalability and cost-effectiveness to current and future communication infrastructures in urban, peri-urban, and rural areas. Full article

17 pages, 8952 KiB

Open AccessArticle

Machine Learning for Identifying Damage and Predicting Properties in 3D-Printed PLA/Lygeum Spartum Biocomposites

by Khalil Benabderazag, Moussa Guebailia, Zouheyr Belouadah, Lotfi Toubal and Salah Eddine Tachi

Fibers 2025, 13(4), 38; https://doi.org/10.3390/fib13040038 - 31 Mar 2025

This paper offers an experimental approach that integrates acoustic emission (AE) monitoring with machine learning (ML) to identify damage mechanisms and predict the mechanical properties of 3D-printed biocomposites. Specimens were fabricated using a bio-filament composed of a PLA matrix reinforced with 10% wt. [...] Read more.

This paper offers an experimental approach that integrates acoustic emission (AE) monitoring with machine learning (ML) to identify damage mechanisms and predict the mechanical properties of 3D-printed biocomposites. Specimens were fabricated using a bio-filament composed of a PLA matrix reinforced with 10% wt. of Lygeum spartum fibers and were subjected to tensile and flexural tests. The processed dataset, comprising six normalized features (cumulative rise, duration, count, frequency, energy, and amplitude) was used to train four ML models: Random Forest Regression (RFR), Support Vector Regression (SVR), Artificial Neural Networks (ANN), and Decision Trees (DT) implemented in Python using libraries such as scikit-learn, pandas, and numpy. The prediction models were developed using an 80/20 train–test split and further validated by 5-fold cross-validation, with performance evaluated by R-squared (R²) and Mean Squared Error (MSE) metrics. Our results demonstrate robust prediction capabilities, with the RFR model achieving the highest accuracy (R² > 0.98 and MSE as low as 0.013 for tensile stress prediction). Additionally, unsupervised clustering using K-means was applied to group AE signals into distinct clusters corresponding to different damage modes. This comprehensive methodology not only enhances our understanding of damage evolution in composite materials but also establishes a data-driven framework for non-destructive evaluation and structural health monitoring. Full article

► Show Figures

Figure 1

24 pages, 8460 KiB

Open AccessArticle

Influence of Coated Steel Fibers on Mechanical Properties of UHPC Considering Graphene Oxide, Nano-Aluminum Oxide, and Nano-Calcium Carbonate

by Seyed Sina Mousavi, Khatereh Ahmadi, Mehdi Dehestani and Jung Heum Yeon

Fibers 2025, 13(4), 37; https://doi.org/10.3390/fib13040037 - 29 Mar 2025

The addition of high volume fractions of fibers in ultra-high-performance concrete (UHPC) presents specific durability-based challenges due to the high content of interfacial transition zones (ITZ) between the fibers and surrounding mortar, along with the production cost. Hence, this study explored a novel [...] Read more.

The addition of high volume fractions of fibers in ultra-high-performance concrete (UHPC) presents specific durability-based challenges due to the high content of interfacial transition zones (ITZ) between the fibers and surrounding mortar, along with the production cost. Hence, this study explored a novel coating approach on the surface of micro steel fibers, considering various nanomaterials, including graphene oxide (GO), nano-aluminum oxide, and nano-calcium carbonate. Poly(vinyl alcohol) (PVA) was employed as a coupling agent. UHPC mixtures containing coated fibers were compared with reference uncoated fiber-reinforced UHPC and UHPC containing GO. The proficiency of the proposed technique was measured through compressive strength, direct tensile, and flexural tests. A microstructure analysis was conducted using scanning electron microscope (SEM) images to determine the ITZ depth surrounding the coated fibers. Findings indicated improvements ranging from 10.7% to 21% for compressive strength, 11.2% to 38% for tensile strength, and 26.6% to 60% for flexural capacity. Full article

► Show Figures

Figure 1

16 pages, 1742 KiB

Open AccessArticle

Modeling and Analysis of the Transverse Surface Roughness in Hollow-Core Fibers

by Federico Melli, Kostiantyn Vasko, Lorenzo Rosa, Fetah Benabid and Luca Vincetti

Fibers 2025, 13(4), 36; https://doi.org/10.3390/fib13040036 - 27 Mar 2025

The corrugation of the interfaces of the cross-section of hollow core fibers based on the inhibited coupling waveguiding mechanism is modeled and the impact on propagation loss analyzed. The proposed model is based on a combined use of coupled-mode theory and Azimuthal Fourier [...] Read more.

The corrugation of the interfaces of the cross-section of hollow core fibers based on the inhibited coupling waveguiding mechanism is modeled and the impact on propagation loss analyzed. The proposed model is based on a combined use of coupled-mode theory and Azimuthal Fourier Decomposition. It shows that such transverse roughness causes coupling between the core modes and the dielectric modes of the cladding and consequently an increase of the fiber loss. The model is validated by comparing theoretical and numerical results obtained by applying both deterministic and stochastic corrugations to tubular lattice and nested fibers. Scaling laws and impact of the fibers’ parameters are discussed. The model shows that the loss increase is not directly correlated to the root mean square of the stochastic roughness but only to the value of the power spectral density in specific spatial frequency ranges. In particular, the spectral components characterized by a periodicity lower than

10^{- 1}

of the tube circumference must have a power spectral density value lower than 0.2 nm² to ensure a negligible effect of the transverse roughness on fibers with losses lower than 0.1 dB/Km. Full article

(This article belongs to the Special Issue Characterization and Applications of Specialty Optical Fibers)

► Show Figures

Figure 1

18 pages, 2385 KiB

Open AccessArticle

Buckling Solution of Fixed–Free Anisotropic Laminated Composite Columns Under Axial Loading

by Rund Al-Masri, Hayder A. Rasheed and Bacim Alali

Fibers 2025, 13(4), 35; https://doi.org/10.3390/fib13040035 - 27 Mar 2025

A generalized buckling solution for anisotropic laminated composite fixed–free columns under axial compression is developed using the critical stability matrix. The axial, coupling, and flexural equivalent stiffness coefficients of the anisotropic layup are determined from the generalized constitutive relationship through the static condensation [...] Read more.

A generalized buckling solution for anisotropic laminated composite fixed–free columns under axial compression is developed using the critical stability matrix. The axial, coupling, and flexural equivalent stiffness coefficients of the anisotropic layup are determined from the generalized constitutive relationship through the static condensation of the composite stiffness matrix. The derived formula reduces down to the Euler buckling equation for isotropic and some special laminated composites. The analytical results are verified against finite element solutions for a wide range of anisotropic laminated layups yielding high accuracy. A parametric study is conducted to examine the effects of ply orientations, element thickness, finite element type, column size, and material properties. Comparisons with numerical results reveal a very high accuracy across the entire parametric profile and a linear correlation between the percentage error and a non-dimensional condensed parameter is extracted and plotted. Full article

► Show Figures

Figure 1

32 pages, 5714 KiB

Open AccessArticle

Polynomial Modeling of Noise Figure in Erbium-Doped Fiber Amplifiers

by Rocco D’Ingillo, Alberto Castronovo, Stefano Straullu and Vittorio Curri

Fibers 2025, 13(3), 34; https://doi.org/10.3390/fib13030034 - 14 Mar 2025

Erbium-Doped Fiber Amplifiers (EDFAs) are fundamental to optical communication networks, providing signal amplification while introducing noise that affects system performance. Accurate noise figure estimation is critical for optimizing link budgets, monitoring optical Signal-to-Noise Ratio (OSNR), and enabling real-time network optimization. Traditional analytical models, [...] Read more.

Erbium-Doped Fiber Amplifiers (EDFAs) are fundamental to optical communication networks, providing signal amplification while introducing noise that affects system performance. Accurate noise figure estimation is critical for optimizing link budgets, monitoring optical Signal-to-Noise Ratio (OSNR), and enabling real-time network optimization. Traditional analytical models, while computationally efficient, often fail to capture device-specific variations, whereas machine-learning-based approaches require large training datasets and introduce high computational overhead. This paper proposes a polynomial regression model for real-time EDFA noise figure estimation, striking a balance between accuracy and computational efficiency. The model leverages Generalized Least Squares (GLS) regression to fit a multivariate polynomial function to measured EDFA noise figure data, ensuring robustness against measurement noise and dataset variations. The proposed method is benchmarked against experimental measurements from multiple EDFAs, achieving prediction errors that are within the measurement uncertainty of Optical Spectrum Analyzers (OSAs). Furthermore, the model demonstrates strong generalization across different EDFA architectures, outperforming analytical models while requiring significantly less data than deep-learning approaches. Computational efficiency is also analyzed, showing that inference time is below 0.2 ms per evaluation, making the model suitable for real-time digital-twin applications in optical networks. Future work will explore hybrid modeling approaches, integrating physics-based regression with Machine Learning (ML) to enhance performance in high-variance spectral regions. These results highlight the potential of lightweight polynomial regression models as an alternative to complex ML-based solutions, enabling scalable and efficient EDFA performance prediction for next-generation optical networks. Full article

► Show Figures

Figure 1

38 pages, 9959 KiB

Open AccessArticle

Application of Carbon-Fiber-Reinforced Polymer Rods and Ultra-High-Performance Fiber-Reinforced Concrete Jackets with Mechanical Anchorage Systems to Reinforced Concrete Slabs

by Firas Hassan Saeed and Farzad Hejazi

Fibers 2025, 13(3), 33; https://doi.org/10.3390/fib13030033 - 13 Mar 2025

The aim of this experimental study was to develop and evaluate the effectiveness of a new strengthening system for reinforced concrete slabs employing external jackets consisting of ultra-high-performance fiber-reinforced-concrete (UHPFRC) and mechanical anchor systems. The issue of debonding between old and fresh concrete [...] Read more.

The aim of this experimental study was to develop and evaluate the effectiveness of a new strengthening system for reinforced concrete slabs employing external jackets consisting of ultra-high-performance fiber-reinforced-concrete (UHPFRC) and mechanical anchor systems. The issue of debonding between old and fresh concrete layers, as well as the efficiency of utilizing CFRP rods, is the primary challenge of applying the UHPFRC jackets with embedded CFRP rods. In this study, we propose a novel retrofitting technique for implementing a mechanical anchor system to improve the binding of fresh UHPFRC jackets with old RC slabs. An experimental test was conducted by subjecting three slabs to cyclic loads by utilizing a dynamic actuator: a reference slab, a retrofitted slab with an external UHPFRC layer, and a retrofitted slab with an external UHPFRC layer incorporating CFRP bars. Furthermore, finite element models (FEMs) were utilized to investigate the responses of the retrofitted slabs and compare the novel method with traditional strengthening techniques, including near-surface-mounted (NSM) CFRP rods, externally bonded CFRP strips, and epoxy-bonded UHPFRC jackets, as well as two models that were the same as the experimental strengthened slab specimens except for the fact that they did not have a mechanical anchor system. Additionally, analytical mechanistic models were employed to determine the flexural moment capacity of the RC slabs. The experimental findings demonstrated that the proposed strengthening strategy considerably prevented premature debonding and enhanced the maximum load of retrofitted RC slabs by over 82%. Also, the FEM and analytical results are significantly consistent with the experimental outcomes. In conclusion, the newly suggested strengthening technique is a reliable system for enhancing the efficacy of slabs, effectively preventing early debonding between existing and new components. Full article

► Show Figures

Figure 1

16 pages, 5970 KiB

Open AccessArticle

Advanced Vibration of Functionally Graded Material Coupled Plates and Circular Shells with Four Layers

by Chih-Chiang Hong

Fibers 2025, 13(3), 32; https://doi.org/10.3390/fib13030032 - 12 Mar 2025

This study is based on typical thermal studies on thick, functionally graded material (FGM)-coupled plates and circular shells. Numerical studies have been previously published by researchers on the linear first-order shear deformation theory (FSDT) model for thin-thickness and two-layer materials. The present relationship [...] Read more.

This study is based on typical thermal studies on thick, functionally graded material (FGM)-coupled plates and circular shells. Numerical studies have been previously published by researchers on the linear first-order shear deformation theory (FSDT) model for thin-thickness and two-layer materials. The present relationship was further studied by the author on the nonlinear third-order shear deformation theory (TSDT) model for thick-thickness and four-layer FGMs. The material properties of FGM layers deal with the effect of temperature. The novelty of this study is in its further consideration of four layers of FGMs and the non-dimensional shear coefficient. The stiffness and stiffness integrals of the four layers are studied. The material properties in the power law expression of the functions of the four layers are assumed for the first time. Under the conditions of a time sinusoidal, varied thermal loads and simply supported conditions for four layers are studied. Parametric case studies involving temperature, the standard power law form of the index, and the nonlinear term of the displacement theory and shear coefficient for the dynamic stresses and displacements are obtained and presented. Full article

► Show Figures

Figure 1

15 pages, 4088 KiB

Open AccessArticle

Durable Hydrophilic PVDF Hollow Fiber Membrane for Dissolved Organics Separation from High-Salinity Produced Water

by Samuel Oppong, Zongjie He, Gabriela Torres Fernandez, Guoyin Zhang and Jianjia Yu

Fibers 2025, 13(3), 31; https://doi.org/10.3390/fib13030031 - 11 Mar 2025

Organic compounds are major constituents in produced water that have gained increasing attention due to their negative impacts on operations and the environment. In this study, a novel hydrophilic polyvinylidene fluoride (PVDF) hollow fiber (HF) membrane was formulated and fabricated for organics separation [...] Read more.

Organic compounds are major constituents in produced water that have gained increasing attention due to their negative impacts on operations and the environment. In this study, a novel hydrophilic polyvinylidene fluoride (PVDF) hollow fiber (HF) membrane was formulated and fabricated for organics separation (OS) from oilfield-produced water. The PVDF dope solution was formulated with lithium chloride (LiCl) and polyvinylpyrrolidone (PVP) as synergistic pore agents, and the obtained PVDF HF membranes showed a defect-free asymmetric structure with a stable hydrophilicity. The OS performance was studied in terms of permeate water flux, OS efficiency, and long-term membrane stability using both decanoic acid and real produced water as feed solutions. Specifically, the effects of operating parameters, such as pressure, total organic carbon (TOC), pH, and salinity, on the OS performance were examined in decanoic acid solution. The long-term membrane stability was evaluated through a 60 h continuous OS experiment using real produced water as the feed solution. The used membrane was thoroughly characterized to understand both scaling and fouling phenomena during the OS operation. The results indicated that the membranes showed promising permeate water flux (>500 kg/m²/h at 350 kPa) and OS efficiency (>92%). It also exhibited a near-100% recovery of organics separation efficiency during six cyclic OS experiments due to consistent membrane hydrophilicity. Full article

► Show Figures

Figure 1

21 pages, 7970 KiB

Open AccessArticle

Production of Decolorized Mushroom Pulp for Nonwoven Cotton Composite

by Ho-Seong Im, Satomi Tagawa, Jae-Seok Jeong and Hyun-Jae Shin

Fibers 2025, 13(3), 30; https://doi.org/10.3390/fib13030030 - 5 Mar 2025

Cotton, widely used in the textile industry, has a significant environmental impact due to soil degradation and excessive water consumption during cultivation. As a result, there is a growing need for biodegradable alternatives. This study pioneers the development of decolorized mushroom pulps (DMPs) [...] Read more.

Cotton, widely used in the textile industry, has a significant environmental impact due to soil degradation and excessive water consumption during cultivation. As a result, there is a growing need for biodegradable alternatives. This study pioneers the development of decolorized mushroom pulps (DMPs) from edible mushrooms as a sustainable replacement for cotton. Decolorization of fruiting bodies showed the highest reactivity with hydrogen peroxide (H₂O₂). At the same time, mycelium responded more effectively to sodium hypochlorite (NaClO), though this led to structural changes such as melting and twisting. Potassium was detected in fruiting bodies but absent in mycelium, and higher salt content was noted in Agaricus bisporus and Trametes orientalis compared to Pleurotus ostreatus and Flammulina velutipes. Future research should focus on preserving mycelial integrity or developing strains that eliminate the need for decolorization treatments, advancing DMPs as viable biotextile materials. Full article

► Show Figures

Figure 1

11 pages, 2484 KiB

Open AccessArticle

High-Pressure Hydrogen Influence on Cellulose Nanofibers Filled Nitrile Rubber: Performance in Storage Applications

by Sheng Ye, Sohail Yasin, Haijie Zhi, Yihu Song, Chaohua Gu and Jianfeng Shi

Fibers 2025, 13(3), 29; https://doi.org/10.3390/fib13030029 - 5 Mar 2025

High-pressure hydrogen storage systems (up to 100 MPa) require advanced materials for safety and reliability, particularly for rubber seals, which are prone to degradation under extreme conditions. This study explores the use of cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs) as sustainable nanofillers [...] Read more.

High-pressure hydrogen storage systems (up to 100 MPa) require advanced materials for safety and reliability, particularly for rubber seals, which are prone to degradation under extreme conditions. This study explores the use of cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs) as sustainable nanofillers for nitrile butadiene rubber (NBR) latex nanocomposites. CNFs and CNCs were evaluated for their effects on mechanical properties, crosslink density, and resistance to high-pressure hydrogen exposure in rubber O-rings. A life cycle assessment (LCA) was carried to assess the environmental impact of these nanocomposites. The results showed that CNF-filled NBR composites exhibited better resistance to bubble formation under hydrogen exposure compared to CNC-filled ones. However, the LCA indicated relatively high environmental impacts for both, reaching up to 2.5 kg CO₂ eq. in Global Warming Potential (GWP), highlighting the need for further optimization of production processes. This study demonstrates the potential of cellulose nanofillers to improve NBR performance while advancing sustainable hydrogen storage materials. Full article

► Show Figures

Figure 1

19 pages, 7052 KiB

Open AccessArticle

Experimental Study on the Valorization of Rice Straw as Fiber for Concrete

by Hesam Doostkami, David Hernández-Figueirido, Vicente Albero, Ana Piquer, Pedro Serna and Marta Roig-Flores

Fibers 2025, 13(3), 28; https://doi.org/10.3390/fib13030028 - 5 Mar 2025

Rice straw is an agricultural waste that is difficult to manage and has traditionally been burned or buried, leading to environmental problems. Because of this, the introduction of rice straw into concrete has been proposed to revalue this residue. This investigation shows experimental [...] Read more.

Rice straw is an agricultural waste that is difficult to manage and has traditionally been burned or buried, leading to environmental problems. Because of this, the introduction of rice straw into concrete has been proposed to revalue this residue. This investigation shows experimental work carried out to prepare rice straw fibers and introduce them into a concrete mix as macrofibers. In addition, three fiber treatments were compared: two alkaline and one thermal. Four concrete mixes were studied: a reference mix, two concrete mixes with untreated rice straw fibers in two dosages, 10 kg/m³ and 15 kg/m³, and a fourth concrete mix with 10 kg/m³ of fiber treated with sodium hydroxide. The properties analyzed are workability, compression flexural strength, and shrinkage. The results show that the rice straw fiber used in this work improves concrete flexural strength at the peak but does not provide post-crack residual flexural strength. The sodium hydroxide treatment was effective in obtaining a more cohesive mix and lower setting time delay and slightly improved the performance of the rice straw fiber at the flexural strength peak. In summary, concrete can be used to encapsulate this agricultural waste material, providing enough strength for several engineering applications (>30 MPa). Full article

► Show Figures

Figure 1

19 pages, 3937 KiB

Open AccessReview

Geometric Characterisation of Stochastic Fibrous Networks: A Comprehensive Review

by Yagiz Kayali, Andrew Gleadall and Vadim V. Silberschmidt

Fibers 2025, 13(3), 27; https://doi.org/10.3390/fib13030027 - 5 Mar 2025

Fibrous networks are porous materials that can have stochastic and uniform microstructures. Various fibrous networks can be found in nature (e.g., collagens, hydrogels, etc.) or manufactured (e.g., composites and nonwovens). This study focuses on the geometrical characterisation of stochastic fibrous networks with continuous [...] Read more.

Fibrous networks are porous materials that can have stochastic and uniform microstructures. Various fibrous networks can be found in nature (e.g., collagens, hydrogels, etc.) or manufactured (e.g., composites and nonwovens). This study focuses on the geometrical characterisation of stochastic fibrous networks with continuous fibres in a 2D domain, discussing their main relevant parameters: basis weight, orientation distribution function, crimp, porosity, spatial distribution of fibres (uniformity), and fibre intersections. The comprehensive review of the literature is combined with original results to understand the effect of the analysed parameters on various features of fibrous networks such as mechanical performance, filtration, insulation, etc. Full article

► Show Figures

Figure 1

43 pages, 27240 KiB

Open AccessArticle

An Experimental Investigation on the Effect of Incorporating Natural Fibers on the Mechanical and Durability Properties of Concrete by Using Treated Hybrid Fiber-Reinforced Concrete Application

by Anteneh Geremew, Amelie Outtier, Pieter De Winne, Tamene Adugna Demissie and Hans De Backer

Fibers 2025, 13(3), 26; https://doi.org/10.3390/fib13030026 - 28 Feb 2025

This research explores the use of treated hybrid natural fibers—wheat straw and bamboo—as reinforcements in concrete for pavement applications. Motivated by environmental and economic benefits, the study investigates how these fibers can enhance the mechanical and durability properties of concrete. Wheat straw fibers, [...] Read more.

This research explores the use of treated hybrid natural fibers—wheat straw and bamboo—as reinforcements in concrete for pavement applications. Motivated by environmental and economic benefits, the study investigates how these fibers can enhance the mechanical and durability properties of concrete. Wheat straw fibers, abundant in Ethiopia due to extensive wheat farming, help control micro-cracks and increase the tensile strength of concrete, while bamboo fibers, also locally available, reduce macro-crack propagation and improve concrete toughness. To prepare these fibers, wheat straw was cut to 25 mm in length and bamboo fibers were treated with a 5% sodium hydroxide solution before being cut into lengths of 30, 45, and 60 mm. A concrete mix targeting a cube compressive strength of 30 MPa incorporated 0.1% wheat straw fibers, with varying bamboo fiber contents (0.5%, 1%, and 1.5%) by weight of cement. The results indicate that the uniquely treated hybrid natural fiber-reinforced concrete mix exhibits noticeable enhancements in mechanical properties, with approximate increases of 4.16%, 8.80%, and 8.93% at 7, 28, and 56 days, respectively. Furthermore, the split tensile strength, flexural strength, and durability properties of the concrete were significantly improved by the proposed fiber concentration and length compared to the control concrete mix design. This treatment also shifted the failure mode of the concrete from brittle to ductile and enhanced its energy absorption capacity up to 7.88% higher than that of the control concrete. Based on the AASHTO 1993 pavement design guidelines, this fiber-reinforced concrete reduces pavement thickness by 11% compared to the control concrete while improving post-cracking behavior. This hybrid natural fiber-reinforced concrete presents a promising, sustainable, and eco-friendly alternative for rigid pavement construction. Full article

► Show Figures

Figure 1

31 pages, 27163 KiB

Open AccessArticle

Synergistic Use of Nanosilica and Basalt Fibers on Mechanical Properties of Internally Cured Concrete with SAP: An Experimental Analysis and Optimization via Response Surface Methodology

by Said Mirgan Borito, Han Zhu, Yasser E. Ibrahim, Sadi Ibrahim Haruna and Zhao Bo

Fibers 2025, 13(3), 25; https://doi.org/10.3390/fib13030025 - 26 Feb 2025

This study explores the combined effects of nanosilica (NS) and basalt fibers (BF) on the mechanical and microstructural properties of superabsorbent polymer (SAP)-modified concrete. NS (0–1.5% replaced by cement weight) and BF (0–1.2% by volume fraction) were incorporated to optimize compressive, flexural, and [...] Read more.

This study explores the combined effects of nanosilica (NS) and basalt fibers (BF) on the mechanical and microstructural properties of superabsorbent polymer (SAP)-modified concrete. NS (0–1.5% replaced by cement weight) and BF (0–1.2% by volume fraction) were incorporated to optimize compressive, flexural, and split-tensile strengths using response surface methodology. Digital Image Correlation (DIC) was employed to analyze failure mechanisms. Results show that while SAP alone reduced strength, the addition of NS and BF mitigated this loss through synergistic microstructure enhancement and crack-bridging reinforcement. The optimal mix (0.9% NS and 1.2% BF) increased compressive, flexural, and split-tensile strengths by 15.3%, 10.0%, and 14.0%, respectively. SEM analysis revealed that NS filled SAP-induced pores, while BF limited crack propagation, contributing to improved mechanical strength of SAP-modified concrete. This hybrid approach offers a promising solution for durable and sustainable concrete pavements. Full article

► Show Figures

Figure 1

16 pages, 5390 KiB

Open AccessArticle

Flammability of Plant-Based Loose-Fill Thermal Insulation: Insights from Wheat Straw, Corn Stalk, and Water Reed

by Martins Andzs, Ramunas Tupciauskas, Andris Berzins, Gunars Pavlovics, Janis Rizikovs, Ulla Milbreta and Laura Andze

Fibers 2025, 13(3), 24; https://doi.org/10.3390/fib13030024 - 24 Feb 2025

This study investigates the fire resistance capabilities of newly developed loose-fill thermal insulation materials crafted from annual plants such as wheat straw, corn stalk, and water reed. Three processing methodologies were employed: mechanical crushing (raw, size ≤ 20 mm), chemi-mechanical pulping (CMP) using [...] Read more.

This study investigates the fire resistance capabilities of newly developed loose-fill thermal insulation materials crafted from annual plants such as wheat straw, corn stalk, and water reed. Three processing methodologies were employed: mechanical crushing (raw, size ≤ 20 mm), chemi-mechanical pulping (CMP) using 4% sodium hydroxide, and steam explosion (SE). An admixture of boric acid (8%) and tetraborate (7%) was added to all treated materials to enhance fire retardancy. The fire reaction characteristics of the insulation materials were assessed using a cone calorimeter measuring the key parameters like time to ignition, total heat release, heat release rate, and total smoke production. The findings indicate that nearly all tested insulation samples, apart from the raw and SE water reed, demonstrated fire resistance comparable to commercial cellulose insulation, surpassing the fire performance of various synthetic foams and composite materials. Furthermore, the single-flame source fire tests indicated that the developed insulation materials achieved a fire classification E, except for the SE water reed sample. Thus, the fire performance results approve the suitability of developed plant-based insulation materials for competing materials in building constructions. Full article

► Show Figures

Figure 1

22 pages, 657 KiB

Open AccessReview

Developments in the Recycling of Wood and Wood Fibre in the UK: A Review

by Morwenna J. Spear, Athanasios Dimitriou, Simon F. Curling and Graham A. Ormondroyd

Fibers 2025, 13(2), 23; https://doi.org/10.3390/fib13020023 - 15 Feb 2025

There is great interest in using bio-based materials to reduce the climate impact of materials. Similarly, there is an increased focus on the circular economy and recycling of materials to increase material efficiency and reduce waste. In the case of wood waste, this [...] Read more.

There is great interest in using bio-based materials to reduce the climate impact of materials. Similarly, there is an increased focus on the circular economy and recycling of materials to increase material efficiency and reduce waste. In the case of wood waste, this provides a cluster of benefits but has led to a high demand for the reclaimed material. This review provides updates on several technologies where wood fibre recycling and products from recycled wood fibre are breaking into new markets, including wood fibre insulation products, wood plastic composites, oriented strand boards, and fibreboards. Emerging technologies, such as the ability to recycle medium-density fibreboards, in addition to the more commonly recycled solid wood or particleboard, will allow for a new set of options within the wood cascading chain. Looking ahead, there are likely to be advances in new composite products, as well as other feedstock materials derived from reclaimed wood, such as nanocellulose, pyrolysis oils, or wood polymers reclaimed from the wood feedstock. This review arose from an investigation into the wood recycling sector in the UK. So, the horizon scanning exercise presented here considers the needs and challenges that may arise, if the volume of recycled wood fibre can be increased, in an already highly active market. Such developments would permit an increase in the manufacture of new-generation long-service-life products to enhance carbon storage, and potentially a shift away from bioenergy generation. Full article

(This article belongs to the Special Issue Natural Fibers for Advanced Materials: Addressing Challenges)

► Show Figures

Figure 1

27 pages, 6006 KiB

Open AccessArticle

Durability, Service Life, and Techno-Economic Analysis of Non-Proprietary UHPC

by Bijaya Rai and Kay Wille

Fibers 2025, 13(2), 22; https://doi.org/10.3390/fib13020022 - 13 Feb 2025

Non-proprietary ultra-high-performance concrete (UHPC) has been developed by numerous research institutes, each exhibiting unique characteristics distinct from both commercial and other non-proprietary UHPC formulations. However, comprehensive techno-economic analyses (TEA) comparing UHPC to conventional concrete, alongside extensive long-term durability assessments, remain limited. This study [...] Read more.

Non-proprietary ultra-high-performance concrete (UHPC) has been developed by numerous research institutes, each exhibiting unique characteristics distinct from both commercial and other non-proprietary UHPC formulations. However, comprehensive techno-economic analyses (TEA) comparing UHPC to conventional concrete, alongside extensive long-term durability assessments, remain limited. This study bridges these gaps by evaluating the long-term durability, modeling service life, and conducting a TEA of resource-efficient non-proprietary UHPCs. Durability characterization was conducted in accordance with ASTM standards, focusing on chloride ion penetration (via electrical surface resistivity), drying shrinkage, freeze–thaw (F–T) resistance, and absorption. These properties were monitored over a year to capture both transient and steady-state performance. A durability assessment factor (κ) was introduced to assess and compare the new UHPCs with existing alternatives. Results demonstrated that the UHPCs achieved high electrical surface resistivity, exceeding the low chloride ion penetration threshold of 21 kΩ∙cm within 1 week of casting. No deterioration was observed after 600 F–T cycles, indicating superior F–T resistance. Drying shrinkage remained below 0.1%, and absorption remained below 1.4%. These results highlight the long-term durability of the UHPCs, with a projected design service life surpassing 350 years, aligning closely with proprietary UHPC products. Full article

► Show Figures

Figure 1

More Articles...

Submit to Fibers Review for Fibers

Journal Menu

Journal Browser

► Journal Browser

Highly Accessed Articles

View More...

Latest Books

More Books and Reprints...

E-Mail Alert

News

2 April 2025
MDPI INSIGHTS: The CEO's Letter #21 - Annual Report, Swiss Consortium, IWD, ICARS, Serbia

28 March 2025
Meet Us at the 12^th International Conference on Fiber-Reinforced Polymer (FRP) Composites in Civil Engineering, 14–16 July 2025, Lisboa, Portugal

21 March 2025
Meet Us at the 2025 Spring Meeting of the European Materials Research Society (E-MRS), 26–30 May 2025, Strasbourg, France

More News & Announcements...

Topics

Propose a Topic

Topic in Applied Sciences, Optics, Sensors, Materials, Fibers, Photonics, Micromachines

Distributed Optical Fiber Sensors Topic Editors: Jian Li, Hao Wu, Giancarlo C. Righini, Zhe Ma, Yahui Wang
Deadline: 15 June 2025

Topic in Fibers, J. Compos. Sci., Materials, Polymers

Advanced Carbon Fiber Reinforced Composite Materials, Volume II Topic Editors: Michela Simoncini, Archimede Forcellese
Deadline: 31 July 2025

Topic in Energies, Fibers, Micromachines, Molecules, Nanoenergy Advances

Advances on the Application of Nanomaterials and 2D Materials for Sensors, Solar Cells, Microelectronics, and Optoelectronics Topic Editors: Alessia Irrera, Antonio Alessio Leonardi
Deadline: 31 December 2025

Topic in Fibers, J. Compos. Sci., Materials, Polymers, Applied Mechanics

Advances in Fiber–Matrix Interface: Cohesion Enhancement, Characterization and Modeling of Interfacial Debonding Topic Editors: Quentin Bourgogne, Hamid Zahrouni, Hubert Chapuis
Deadline: 28 February 2026

Conferences

Announce Your Conference

More Conferences...

Special Issues

Propose a Special Issue

Special Issue in Fibers

Fracture Behavior of Fiber-Reinforced Building Materials Guest Editor: Anastasios C. Mpalaskas
Deadline: 20 April 2025

Special Issue in Fibers

Applied Research on Polymer and Natural Fiber Composite Processing Guest Editor: Monica Silva
Deadline: 30 April 2025

Special Issue in Fibers

Natural Fibers for Advanced Materials: Addressing Challenges Guest Editors: Pratheep Kumar Annamalai, Stuart G. Gordon
Deadline: 25 May 2025

Special Issue in Fibers

Characterization and Applications of Specialty Optical Fibers Guest Editor: Mario F. S. Ferreira
Deadline: 25 May 2025

More Special Issues

Topical Collections

Topical Collection in Fibers

Feature Papers in FibersCollection Editors: Ionela Andreea Neacsu, Alexandru Grumezescu

Topical Collection in Fibers

Review Papers of FibersCollection Editor: Martin J. D. Clift

Back to TopTop