Durability Of Fibers Research Articles

Evaluation of the long-term performance and durability of basalt fiber reinforced polymer bars in concrete structures

To simulate the internal corrosion process of basalt fiber reinforced polymer (BFRP) bars in an alkaline environment of concrete, a diffusion based model was employed and modified in this study according to Fickian diffusion and diffusion coefficients at 25 ℃, 40 ℃, and 55 ℃ obtained from existing studies. Thus, the long-term corrosion medium concentration diagram, degraded depth, and strength retention of BFRP bars in the concrete environment at any ambient temperature can be predicted. Durability tests of BFRP bars in an alkaline solution at 60 ℃ were conducted to verify that the diffusion based model’s predictions were accurate. Moreover, long-term bonding tests between BFRP bars and concrete were conducted. The results indicate that the predicted results of the degraded depth and strength degradation of BFRP bars corresponded well to the experimental data. Morphology analysis by scanning electron microscopy (SEM) indicates that the alkaline solution intrusion caused the resin matrix to deteriorate, the fibers and the resin to debond, and the reaction between OH- and SiO2 in the fibers to occur, which in turn caused the tensile and bonding strengths of FRP bars to degrade. Moreover, after 63 days of corrosion at 55 ℃, the degraded depth exceeded 7 times that of 25 ℃ and 2 times that of 40 ℃, which implies that the ambient temperature had an obvious influence on the deterioration of BFRPs. The degradation rate was extremely slow at room temperature and rapidly accelerated with the rise in temperature.

Effect of wetting/drying cycles on the durability of flax fibers reinforced earth concrete

Earth concrete is composed of fine particles which make them very sensitive to humidity and affects their long-term durability. In this study, the effect of wetting/drying cycles on earth concrete according to ASTM D559 was studied by measuring the weight loss, pH, and Electrical Conductivity (EC). The effect of different percentages of flax fibers was investigated. The residual properties of reference specimens and earth concrete specimens subjected to wetting/drying cycles were evaluated by conducting compressive tests at the end of the 25 cycles. Ultrasound, Acoustic Emission (AE), and Digital Image Correlation (DIC) techniques were applied to estimate the concrete progressive deterioration during and at the end of the 25 wetting/drying cycles. The results showed that earth concrete degradation begins during the first cycle with visible cracks on the surface of the specimens. The mechanical tests showed a considerable loss of earth concrete mechanical properties after 25 cycles. The ultrasonic test showed that the degradation rate was more important for specimens without flax fibers. The cumulative acoustic activity was effectively used to assess the different damage progression phases and crack propagation. The signal parameters (energy, amplitude, etc.) evolution indicates premature damage for earth concrete specimens subjected to wetting drying cycles.

A review on integration of carbon fiber and polymer matrix composites in 3D printing technology

Three-dimensional (3D) printing applications obtained by combining the lightness, high strength, and durability of carbon fiber with polymer matrix composites provide various industrial advantages. These advantages offer new design and production opportunities for automotive, aviation, space, medical devices, and many other industrial fields. This review article discusses material innovations in 3D printing technology with a focus on the integration of carbon fiber and polymer matrix composites. After examining the current state and future potential of 3D printing technology, the properties and advantages of carbon fiber and polymer matrix composites and the difficulties encountered with their integration into the 3D printing process were examined. In conclusion, this review article comprehensively discusses the current status, advantages, challenges, and future directions on the integration of carbon fiber and polymer matrix composites in 3D printing technology. This article can be an important resource for industry professionals and researchers in materials science and engineering.

Exploring the strength and durability of hemp fiber reinforced moringa bioresin composites for skateboard applications

The study aimed to develop and analyze bio-based composites, incorporating moringa bioresin and hemp fibers as reinforcing elements. The composites were fabricated using four weight percentage combinations of epoxy, moringa bioresin, and hemp fiber. The fabricated composites were characterized by their mechanical, thermal, water absorption, biodegradability, and morphological properties. The study revealed that the composite with the highest proportion of moringa bioresin (30 wt. %) exhibited better mechanical properties. Moreover, the flexural strength and Shore D hardness were impacted by both the matrix and reinforcing materials’ weight percentages. Thermal analysis showed that the composites had good thermal stability, while water absorption analysis indicated that the composites had good water resistance. Biodegradability analysis showed that the composites had a high rate of biodegradation, making them environmentally friendly. The distribution of reinforcing fibers within the matrix material was found to be uniform through the use of scanning electron microscope based morphological analysis. The results indicate that moringa bioresin and hemp fiber composites have the potential to be used as sustainable alternatives to petroleum-based composites in various applications.

Properties evolution and deterioration mechanism of steel fiber reinforced concrete (SFRC) under the coupling effect of carbonation and chloride attack

Carbonation of concrete and chloride-induced corrosion of steel fiber are two potential threats to the durability of steel fiber reinforced concrete (SFRC). In this study, the properties evolution of SFRC under the coupling effect of carbonation and chloride attack was investigated, and the deterioration mechanism was also explored. Results showed that the compressive strength of SFRC increased during the 360 days under the coupling effect of carbonation and chloride attack. However, the flexural properties exhibited an increasing trend before 120 days, with peak strength and flexural toughness rising by 60.8 % and 43.9 %, respectively, followed by a subsequent decline, which were lower than initial flexural properties after 360 days. Compared to the single chloride attack, the coupling effect of carbonation and chloride attack accelerated the corrosion process of SFRC. After 360 dry-wet cycles of chlorides, the inner steel fibers within approximately 10 mm from the SFRC surface were severely corroded, while steel fibers at the deeper depths remained uncorroded despite the chlorides ions penetration depth exceeding 40 mm. Furthermore, the deterioration process and potential mechanism of SFRC was elaborated upon, which provides empirical evidence and establishing a theoretical foundation for the development of highly corrosion-resistant SFRC.

Water absorption and property evolution of epoxy resin under hygrothermal environment

Changes in structure and properties of resin matrix caused by water absorption is one of the key factors affecting the long-term durability of fiber reinforced polymer composites used in civil engineering. In the present study, the water diffusion and structural change in an epoxy resin were investigated experimentally through immersion in deionized water at 40, 60 and 80 °C for 135 days. Water absorption, thermal, mechanical and microstructure analysis tests were conducted to evaluate the long-term property evolution. It was found that the water absorption of epoxy resin followed a two-stage model, including an initial Fick's diffusion response and a subsequent relaxation response. Long-term hygrothermal exposure brought about the structural change of epoxy resin, which led to the significant degradation up to 8%–30% in the mechanical properties and 21% in glass transition temperature, respectively. The resin plasticization and hydrolysis was the key factors for the degradation of thermal and mechanical properties. It was proved that the plasticization effect was reversible with the remove of bonding water after the drying. Based on the Arrhenius equation, the long-term life of flexural strength in two service environments were predicted to provide the application guideline. The significant degradation of flexural strength was occurred at the initial exposure of 2000 days and then reached to the stable strength retention of 69.6%.

Asymmetric ionic bond shielding encountering with carboxylate capturing metal ions for enhancing the flame retardant durability of regenerated cellulose fibers

Enhancing the flame retardancy and durability of cellulose fibers, particularly environmentally friendly regenerated cellulose fibers types like Lyocell fibers, is essential for advancing their broader application. This study introduced a novel approach to address this challenge. Cationic-modified Lyocell fibers (Lyocell@CAT) were prepared by introducing quaternary ammonium structures into the molecular chain of Lyocell fibers. Simultaneously, a flame retardant, APA, containing -COO−NH4+ and -P=O(O−NH4+)2 groups was synthesized. APA was then covalently bonded to Lyocell@CAT to prepare Lyocell@CAT@APA. Even after undergoing 30 laundering cycles (LCs), Lyocell@CAT@APA maintained a LOI value of 37.2 %, exhibiting outstanding flame retardant durability. The quaternary ammonium structure within Lyocell@CAT@APA formed asymmetric ionic bonds with the phosphate and carboxylate groups in APA, effectively shielding the binding of Na+ ions with phosphate groups during laundering, thereby enhancing the durability. Additionally, the consumption of Na+ ions by carboxylate groups further prevented their binding to phosphate groups, which contributed to enhance the durability properties. Flame retardant mechanism analysis revealed that both gas and condensed phase synergistically endowed excellent flame retardancy to Lyocell fibers. Overall, this innovative strategy presented a promising prospect for developing bio-safe, durable, and flame retardant cellulose textiles.

Enhancing alkali resistance of recycled GFRP fibers and mechanical performances of cement mortars with microbial induced carbonate precipitation

Applying the recycled glass fiber reinforced plastic (rGFRP) fiber to reinforce cement-based materials is a promising way to reuse this massively waste material. However, rGFRP fiber is prone to be corroded in the alkali environment of cement. To solve this problem, the rGFRP fiber was treated with microbial induced CaCO3 precipitation (MICP) technique. The effects of MICP treatment on the rGFRP fiber and the reinforced mortar were investigated. It was revealed that the alkali resistance of the rGFRP fiber was significantly modified by CaCO3 deposition, which was increased with the concentration of mineralizing solution and treating time. The tensile strength and aging resistance of the rGFRP fiber reinforced mortar were all improved by MICP treatment, since fiber-cement friction, fiber-cement compatibility, microstructural compactness and cement hydration degree were enhanced by the properly precipitated CaCO3 crystals on fiber surface. However, excessive MICP treating process was detrimental for effective CaCO3 precipitation. The rGFRP fiber treated in the mineralizing solution of 1.0 mol/L for 3 times with 24 h/time (1−24−3) had the most promising modification effect on the rGFRP fiber and the reinforced mortar in this study. The 1–24–3 rGFRP fiber had similar alkali resistance to the alkali resistance glass fiber, which increased the tensile strength of mortar by 34.1 % and improved the bending strength of mortar by 10.8 % after accelerated aging. The MICP technique was used on modifying rGFRP fiber and the reinforced mortar for the first time, which would benefit the durability of rGFRP fiber and its wider application in cement-based materials, while the long-term performance of rGFRP fiber reinforced mortar should be studied in the future.

Enhancing mechanical properties of natural waste‐based composites for automobile and plastic industry

AbstractNatural fiber composites are a renewable and environmentally friendly alternative to conventional synthetic materials that combine the biodegradability and essential durability of natural fibers with adaptability. Improved adhesion between fibers and matrix can be accomplished by comparing surface treatments applied to sugarcane, water hyacinth, and banana plant wastes. This will allow us to produce composite materials that are more durable and sustainable. To study the mechanical and morphological characteristics of the composites, two surface treatments were applied: gamma radiation at a dose of 1, 2, 3, 4 and 5 kGy and alkali treatment at a concentration of 5, 10, and 15%. The study revealed that with the increasing treatment of alkali solution, improvements in the composite's mechanical characteristics whereas gamma irradiation treatment enhanced the mechanical properties to a certain extent (2 kGy) after that the mechanical traits dwindled significantly. SEM, XRD, and FTIR analysis of the developed composite samples also revealed the reasons for the improvements in mechanical properties after alkali and gamma radiation treatments. As an ecofriendly and lightweight substitute for conventional materials, bio epoxy composites reinforced with natural fibers can be used for car interior panels, eco‐friendly furniture and as a replacement for any plasticware offering eco‐sustainability for contemporary living space.Highlights Natural fiber composites offer a renewable and eco‐friendly alternative to synthetic materials, combining biodegradability with durability. Surface treatments like gamma radiation and alkali treatment enhance composite's mechanical properties. Higher concentrations of alkali treatment improve mechanical characteristics, while gamma irradiation peaks at 2 kGy. Surface treatments offer promising avenues for advancing environmentally friendly materials, contributing to sustainable innovations in material science.

Comparative analysis of swelling mitigation in marl and clay soils: natural plant fibers (Alfa, jute, sisal) vs. polypropylene fiber with lime-pozzolana cement utilizing proctor compaction

This study offers a comparative assessment of two methodologies for mitigating soil swelling in marl and clay soils. The methods under investigation include the use of natural plant fibers (Alfa, jute, sisal) and polypropylene fibers in combination with lime-pozzolana cement. Laboratory tests, including Proctor compaction tests, and swell potential assessments, were conducted to assess the effectiveness of each method. The findings reveal that both natural plant fibers and polypropylene fibers, when combined with lime-pozzolana cement, effectively reduce soil swelling. The study underscores the promise of eco-friendly natural plant fibers and the durability of polypropylene fibers as viable solutions for soil stabilization. Furthermore, incorporating lime-pozzolana cement enhances both methods performance, providing an additional layer of soil stability. This research contributes valuable insights to geotechnical engineering projects dealing with marl and clay soils. It aids in the selection of suitable soil stabilization techniques, considering project-specific needs and sustainability concerns. Ultimately, this study advances the field of geotechnical engineering by promoting environmentally conscious and resilient solutions to address soil swelling in clay and marl soils.

Experimental study on durability of steel-basalt fiber reinforced concrete under multiple factors coupling

A series of durability tests were conducted using varying composite salt solutions (5% Na2SO4 + 3.5% NaCl, 10% Na2SO4 + 3.5% NaCl, and 3.5% NaCl) and stress levels (F-0.3, F-0.6) to investigate the durability of concrete reinforced with steel and basalt fibers. Specimens were extracted after 0, 25, 50, 75, 100, 125, and 150 wet-dry cycles to explore the changes in the appearance, mass loss, relative dynamic modulus of elasticity, and compressive strength with the number of wet-dry cycles and different coupling effects. Mathematical models correlating mass and compressive strength with wet-dry cycles and stress levels were separately established. The concrete microstructure under coupling effects was observed using Environmental Scanning Electron Microscopy (ESEM). The results indicated that the inhibitory effect on the increase in concrete mass was higher in the F-0.6 group than in the F-0.3 group, showing that concrete under F-0.3 exhibited faster mass growth. As the axial compressive stress ratio increased, steel-basalt fiber reinforced concrete's relative dynamic modulus of elasticity changed less. Concrete degradation was more pronounced in the 10% Na2SO4 + 3.5% NaCl solution and F-0.6 loading environment. The calculated results from the established models agreed with the experimental results, demonstrating a certain degree of feasibility.

Continuous production of ultratough semiconducting polymer fibers with high electronic performance.

Conjugated polymers have demonstrated promising optoelectronic properties, but their brittleness and poor mechanical characteristics have hindered their fabrication into durable fibers and textiles. Here, we report a universal approach to continuously producing highly strong, ultratough conjugated polymer fibers using a flow-enhanced crystallization (FLEX) method. These fibers exhibit one order of magnitude higher tensile strength (>200 megapascals) and toughness (>80 megajoules per cubic meter) than traditional semiconducting polymer fibers and films, outperforming many synthetic fibers, ready for scalable production. These fibers also exhibit unique strain-enhanced electronic properties and exceptional performance when used as stretchable conductors, thermoelectrics, transistors, and sensors. This work not only highlights the influence of fluid mechanical effects on the crystallization and mechanical properties of conjugated polymers but also opens up exciting possibilities for integrating these functional fibers into wearable electronics.

Hybrid effect on tensile, flexural, and quasi-static punch shear behavior of jute/ramie and jute/flax reinforced hybrid composites

Abstract The high specific properties and environmental durability of synthetic fibers make them a popular choice for reinforcing lightweight composites. Unfortunately, they are often limited by their poor biodegradability and high cost. Nevertheless, natural fibers are critical in industrial applications due to their environmental and economic benefits. This study investigated the tensile and flexural behavior of natural hybrid jute/ramie and jute/flax composites with different stacking sequences. A quasi-static punch shear test was also performed to understand their deformation behavior. Jute, ramie, and flax composites have also been fabricated for comparison. Tensile and flexural tests showed a positive hybrid effect in some samples, whereas flax–jute hybrid composites in two different stacking sequences exhibited a synergistic effect. While a maximum improvement of 37.99 % was achieved in the tensile test, this rate was 64.81 % in the flexural test with these hybrid composites. According to punch shear experiments, punch geometry and stacking sequence considerably impact punch shear strength, energy absorption capacity, and deformation.

Study on the durability of polyvinyl alcohol fiber reinforced concrete constructed by mixing - casting and mixing - spraying technology in seawater

Polyme fiber-reinforced concrete, with many superior features has solved some limitations of regular concrete. However, polyme fiber reinforced concrete to ensures long-term durability in sea water environments, it is necessary to combine many factors such as quality requirements material, durability and production technology of concrete,... This paper presents the experimetal results on the influence of durability (flexural strength, compressive strength) of polyme fiber (used polyvinyl alcohol fiber – PVA) reinforced concrete using mixing - casting and mixing - spraying technology in sea water environment. The experimental results show that PVA fiber reinforced concrete has the same strength development as normal concrete in both normal water and seawater. The strength of PVA fiber reinforced concrete cured in seawater environment at long-term ages (90 and 180 days) lower than that cured in normal water is 4.5%.

Enhancing Concrete Properties with Agave Americana Fiber Reinforcement.

This research article explores the potential of using agave Americana fibers (AAFs) to enhance the physical and mechanical properties of concretes. The study investigates the impact of AAFs on concrete mix proportions in detail. Different concrete compositions are systematically created by integrating AAFs into them. The chemical structure, crystallinity, morphology, and tensile strength of extracted AAFs are examined, revealing a low cellulose content and a crystallinity index of around 41.34%. The microstructural analysis highlights the rough surface morphology of the extracted AAFs. The research also evaluates how AAFs affect concrete density, water uptake, and flexural and compressive strengths across various mixtures. The results show that incorporating AAFs in a horizontal position can increase the flexural resistance by up to 99% and the compressive resistance by up to 86% without chemical reactions occurring with mud-lime concrete. However, it is worth noting that using AAFs with cement can affect fiber durability due to the alkaline environment. As the alkali concentration increases, the fiber mechanical resistance decreases. Therefore, it is recommended to use AAFs with noncement concrete for improved sustainability and durability. Overall, this study advances our understanding of eco-friendly and resilient concrete materials.

Innovative mushroom-like hemp-based evaporators enhanced by biochar for efficient seawater desalination

Inadequate access to clean water and wasteful resource consumption during production pose significant challenges in global development. To combat these issues, interfacial solar steam generation (ISSG) has emerged as an energy-efficient solution to mitigate the ongoing water scarcity crisis. However, the application of ISSG is hindered by high costs and intricate fabrication processes associated with synthetic functional materials. In response, this study introduces an innovative approach that repurposes abundant by-products generated from hemp fiber production. Hemp fiber noil are transformed into a nonwoven fabric substrate, onto which hemp stem-derived biochar is seamlessly integrated using a straightforward spray-coating technique, establishing an efficient solar-to-heat conversion evaporator. Leveraging the durability of hemp fibers, this system achieves an impressive seawater evaporation rate of 1.47 kg m−2 h−1 under 1 sun condition, making it highly competitive in seawater desalination research. This pioneering strategy combines waste green materials and their functional counterparts, unlocking practical applications, addressing resource scarcity, and mitigating environmental pollution. This research highlights the potential of sustainable material utilization to tackle pressing global challenges.

Impact resistance and durability of natural fibre reinforced concrete pavement and partial replacement with steel slag aggregate

Impact resistance and durability of natural fibre reinforced concrete pavement and partial replacement with steel slag aggregate

A review of the mechanical properties and durability of basalt fiber recycled concrete

Basalt fiber (BF) is an emerging environmentally-friendly fiber. Adding basalt fiber can improve the deficient recycled concrete's poor mechanical properties and durability. By reviewing nearly 120 related papers, the effects of variables such as BF content and length (0–1.5%, 9–18 mm), recycled aggregate substitution rate (0–100%), and cement mix ratio (w/b, 0.25–0.45) on the mechanical and durability properties of basalt fiber-reinforced recycled concrete (BFRAC) were discussed. Due to the presence of vulnerable interfacial transition zones, the mechanical properties of recycled concrete (RAC) continuously deteriorate over time. However, by adding an appropriate amount of basalt fiber, it is possible to improve these structural defects by forming a network structure that enhances cracking resistance within the matrix and improves interface bonding strength among other benefits. Consequently, this significantly improves the overall mechanical properties of RAC. Additionally, while incorporating recycled aggregate (RA) may reduce compressive strength initially, this deficiency can be mitigated through the proper inclusion of fibers in RAC mixtures. Optimal compressive strength for RAC is achieved with a replacement ratio between 25–50% and a fiber content ranging from 0.2–0.3%. Furthermore, properly incorporating fibers into RAC greatly enhances splitting tensile strength and flexural strength as well; specifically achieving optimal splitting tensile strength with a replacement ratio between 40%− 50%, a fiber content at 0.3%, and utilizing fibers with lengths measuring approximately 12 mm long. The primary cause for poor frost resistance in RAC lies within numerous micro-cracks and pores present in RA aggregates which lead to high water absorption rates ultimately reaching critical water saturation points resulting in freeze-thaw damage occurrences during exposure to freezing conditions. When exposed to sulfate attack, RAC undergoes a chemical reaction with sulfate ions present in the concrete, leading to the formation of numerous expansion products that negatively impact concrete performance. Progressive dehydration of hydration products under high-temperature conditions leads to a porous structure within the concrete matrix. Incorporating fibers can impede microcrack expansion during freeze-thaw, sulfate attack, and high-temperature environments, thus enhancing the erosion resistance of RAC. Compared to conventional concrete, interfacial bonding in RAC is less tight and more vulnerable to damage in complex environments. Current research on RAC suggests that the mechanism behind its damage under complex freeze-thaw load coupling environments remains unclear. It is recommended that future studies combine large-scale component tests with computational simulations to address this issue.

Failure mechanism of bonding between natural fiber and cement matrix at high temperature

The debonding behavior of natural fibers with cement matrix at elevated temperatures has been investigated by introducing a new test method for measuring the interfacial shear strength between the fibers and the cement matrix in the field of cementitious composites research. In addition, the effects of shrinkage, surface roughness, and tensile strength changes of natural fibers on the interface at high temperatures were analyzed by characterizing the failure process of chemical bonding with the matrix due to changes in the surface functional groups of natural fibers. The results show that the bonding properties between natural fibers and the cement matrix gradually decrease with increasing temperature, which is due to the contraction of the natural fibers in the radial direction at high temperatures leading to debonding with the cement matrix on the one hand, and the degradation of chemical bonding enhancement due to the reduction of polar groups on the surface of the fibers on the other hand, which contributes to the reduction of the interfacial strength between the fibers and the matrix. In the post-high-temperature phase, the temperature dependence of the inherent material properties of the natural fibers leads to a decrease in the mechanical properties as an additional factor affecting the interfacial behavior. This work evaluates the durability of natural fibers in cement matrices under high temperature conditions from the viewpoint of their inherent physical properties and surface chemical properties, providing unique research ideas and insights for related studies. Meanwhile, a new experimental method is introduced in the field of fiber-reinforced cementitious composites interface research, which can be widely attempted to be used in the study of selective combinations of different fiber-matrix interfaces, fiber size selection, and fiber modification to optimize the overall performance of the composites, which is of great significance to the research in this field.

Effect of sand coating on durability and micro-structural deterioration of GFRP rebar under alkaline environment attack

The objective of this study is to investigate the consequences of the sand-coated layer on the durability of glass fiber reinforced polymer (GFRP) rebars under four alkali solution concentrations and three temperatures. A total of 464 GFRP rebars specimens were manufactured to undergo accelerated corrosion experiments and mechanical performance test. Among them, 438 specimens were used to test the residual tensile strength of GFRP rebars after 120 days of immersion; 26 specimens were applied for surface observation and microscopic testing to analyze the degradation and damage process of GFRP rebars. SEM and digital camera were used to examine the micro-structure of samples either with or without sand layer covering. The unidirectional tensile strength experiment was conducted to test the remaining tensile strength of GFRP rebars after corrosion. The experimental results indicate that sand coating provides better protection and restraint in GFRP rebar durability reduction, resulting in a lower rate of fiber loosening and resin cracking and flaking when exposed to a solution over a pH of 12.5. As the failure of GFRP rebars ranges from local damage to cracking of the peripheral sand protective layer, the pH value of 12.5 is considered a critical alkali solution concentration. Based on experimental results, an improved model was proposed to predict the short-term and long-term residual strength values of GFRP rebars. The calculation results indicate that the predict values are in good agreement with the experimental ones, and the proposed model can be used to predict the residual strength of GFRP rebars.