Showing papers on "Fiber published in 2019"
TL;DR: In this article, MXene flakes are added into PAN solutions at a weight ratio of 2':'1 (MXene' :'PAN) in the spinning dope, producing fiber mats with up to 35 wt% MXene.
Abstract: Free-standing Ti3C2Tx MXene/carbon nanofiber electrodes are prepared via electrospinning Ti3C2Tx MXene flakes with polyacrylonitrile (PAN) and carbonizing the fiber networks. Using this simple fabrication method, delaminated MXene flakes are embedded within carbon nanofibers and these fiber mats are used as electrodes without binders or additives. Unlike coated electrodes, which may suffer from the active material delaminating from the substrate during folding or bending, composite electrodes are stable and durable. Previous attempts to incorporate Ti3C2Tx MXene into electrospun fibers resulted in low mass loadings, ∼1 wt% Ti3C2Tx MXene. In this work, MXene flakes are added into PAN solutions at a weight ratio of 2 : 1 (MXene : PAN) in the spinning dope, producing fiber mats with up to 35 wt% MXene. Composite electrodes have high areal capacitance, up to 205 mF cm−2 at 50 mV s−1, almost three times that of pure carbonized PAN nanofibers (70 mF cm−2 at 50 mV s−1). Compared with electrospun nanofibers spray-coated with Ti3C2Tx, these composite fibers exhibit double the areal capacitance at 10 mV s−1. This method can be used to produce MXene composite fibers using a variety of polymers, which have potential applications beyond energy storage, including filtration, adsorption, and electrocatalysis, where fibers with high aspect ratio, accessible surface, and porosity are desirable.
383 citations
TL;DR: In this paper, an innovative extruder is designed and manufactured for fused deposition modeling (FDM) 3D printers in order to produce continuous fiber reinforced thermoplastic (CFRT) composites.
Abstract: Additive manufacturing of fiber reinforced composites is of great interest in various industrial applications. In this study, an innovative extruder is designed and manufactured for fused deposition modeling (FDM) 3D printers in order to produce continuous fiber reinforced thermoplastic (CFRT) composites. There are some challenges along this way such as making tension in fiber, fiber surface preparation, printing temperature and feed rate to produce a composite part with good quality. These challenges are discussed in detail. The main advantage of this extruder is that it can be mounted on the available FDM 3D printers and consequently there is no need to design a new chassis. In order to assess the quality of products, standard tensile and three-point bending specimens made of pure poly lactic acid (PLA) and carbon fiber reinforced PLA are printed and tested under quasi-static loading. Experimental results show significant improvements of tensile and bending properties of PLA. Morphological analysis is also conducted to study the bonding between the carbon fiber and PLA.
278 citations
TL;DR: The current knowledge regarding dietary fiber, sources of food containing fiber, atherosclerosis, and heart disease risk reduction is summarized.
Abstract: Observational studies have shown that dietary fiber intake is associated with decreased risk of cardiovascular disease. Dietary fiber is a non-digestible form of carbohydrates, due to the lack of the digestive enzyme in humans required to digest fiber. Dietary fibers and lignin are intrinsic to plants and are classified according to their water solubility properties as either soluble or insoluble fibers. Water-soluble fibers include pectin, gums, mucilage, fructans, and some resistant starches. They are present in some fruits, vegetables, oats, and barley. Soluble fibers have been shown to lower blood cholesterol by several mechanisms. On the other hand, water-insoluble fibers mainly include lignin, cellulose, and hemicellulose; whole-grain foods, bran, nuts, and seeds are rich in these fibers. Water-insoluble fibers have rapid gastric emptying, and as such may decrease the intestinal transit time and increase fecal bulk, thus promoting digestive regularity. In addition to dietary fiber, isolated and extracted fibers are known as functional fiber and have been shown to induce beneficial health effects when added to food during processing. The recommended daily allowances (RDAs) for total fiber intake for men and women aged 19–50 are 38 gram/day and 25 gram/day, respectively. It is worth noting that the RDA recommendations are for healthy people and do not apply to individuals with some chronic diseases. Studies have shown that most Americans do not consume the recommended intake of fiber. This review will summarize the current knowledge regarding dietary fiber, sources of food containing fiber, atherosclerosis, and heart disease risk reduction.
256 citations
TL;DR: In this paper, the theory and design of various superwetting states for selective oil/water separation including superhydrophobicity/superoleophilicity, super-hydrophilicity/underwater superoleophobicity, Janus wettability, and smart Wettability are discussed.
249 citations
TL;DR: In this paper, the mechanical properties of high performance concrete reinforced with basalt fiber and polypropylene fibers were investigated, and a conversion relationship between flexural strength and cube compressive strength was proposed.
239 citations
TL;DR: In this article, an optimal basalt fiber content was determined basing firstly on suitable printability and then on mechanical performance using a self-developed 3D printer for extrusion of the cementitious material and also for mechanical enhancement of fiber alignment along the print direction.
224 citations
TL;DR: A facile wet-spinning approach for fabricating nanofibrous Kevlar (KNF) aerogel threads with high thermal insulation under extreme environments is demonstrated and a series of functionalized fibers or textiles based on KNFaerogel fibers, such as phase-change fibers, conductive fibers, and hydrophobic textiles, have been prepared.
Abstract: Aerogel with low density, high porosity, and large surface area is a promising structure for the next generation of high-performance thermal insulation fibers and textiles. However, aerogel fibers suffer from weak mechanical properties or complex fabricating processes. Herein, a facile wet-spinning approach for fabricating nanofibrous Kevlar (KNF) aerogel threads ( i.e., aerogel fibers) with high thermal insulation under extreme environments is demonstrated. The aerogel fibers made from nanofibrous Kevlar render a high specific surface area (240 m2/g) and wide-temperature thermal stability. The flexible and strong KNF aerogel fibers are woven into textiles to illustrate the excellent thermal insulation property under extreme temperature (-196 or +300 °C) and at room temperature. COMSOL simulation is applied to calculate the thermal conductivity of a single aerogel fiber and find an effective way to improve the thermal insulation property of the aerogel fiber. Furthermore, a series of functionalized fibers or textiles based on KNF aerogel fibers, such as phase-change fibers, conductive fibers, and hydrophobic textiles, have been prepared. Such KNF aerogel fibers represent a promising direction for the next generation of high-performance fibrous thermal-insulation materials.
211 citations
TL;DR: This Review summarizes the preparation and compositions of polymer fibers, as well as their characteristics, and affords constructive suggestions for the development of polymer fiber scaffolds in bone and cartilage tissue engineering.
201 citations
TL;DR: In this paper, a functionalized graphene oxide (GO) nanosheets with different contents was introduced into the carbon fiber (CF) interface by sizing process and the uniform distribution of GO sheets on CF surface and the enhancement of surface roughness were obtained.
Abstract: To improve the dispersion of graphene oxide (GO) nanosheets in sizing agent and to enhance the interfacial adhesion between GO and epoxy, GO nanosheets were chemically modified with cyanuric chloride (TCT) and diethylenetriamine (DETA). The functionalized GO (i.e. GO-TCT-DETA) with different contents was introduced into the carbon fiber (CF) interface by sizing process. The uniform distribution of GO sheets on CF surface and the enhancement of surface roughness were obtained. Moreover, significant enhancements (i.e., 104.2%, 100.2%, and 78.3%) of interfacial shear strength (IFSS), interlaminar shear strength (ILSS), and flexural properties were achieved in the composites with only 1.0 wt% GO-TCT-DETA sheets introduced in the fiber sizing. The GO-TCT-DETA in the interface region enhanced the stress being transferred effectively and the local stress concentrations being relieved. This study indicates that the utilization of functionalized GO is one of the alternative approaches for controlling the fiber-matrix interface and improving the mechanical properties of CF epoxy composites.
193 citations
TL;DR: In this paper, a hierarchical porous, high specific surface area ABP (H-ABP) fiber was fabricated via self-assembly of axial grafting chains, which achieved a high adsorption capacity of 11.50 mg-U per g-adsorbents.
Abstract: The development of amidoxime-based polymeric (ABP) fibers offers a solution for uranium extraction from seawater (UES) and provides an alternative solution to the uranium resource shortage. However, ABP adsorbents prepared by existing methods cannot meet the requirements of high adsorption capacity, high selectivity, good mechanical strength and long service life. Herein, we fabricated a 3D hierarchical porous, high specific surface area ABP (H-ABP) fiber via self-assembly of axial grafting chains. A high adsorption capacity of 11.50 mg-U per g-adsorbents was achieved in natural seawater, which is a significant breakthrough in UES. Meanwhile, the adsorption capacity of uranium was higher than its major competing element vanadium, which overturned the U/V mass ratio of the ABP fiber. The H-ABP fiber also exhibited good mechanical strength and a long service life of at least 10 adsorption–desorption cycles. The well-designed structure resulted in groundbreaking properties, which completely meet the requirements for the economic evaluation of UES. This work presents a new technology for the synthesis of highly efficient adsorbents for UES, thus opening a whole new means of nuclear fuel production from the ocean.
191 citations
TL;DR: In this article, the feasibility of recycling composite wind turbine blade components that are fabricated with glass fiber reinforced Elium® thermoplastic resins was determined, and several experiments were conducted to tabulate important material properties that are relevant to recycling, including thermal degradation, grinding and dissolution of the polymer matrix to recover the constituent materials.
TL;DR: In this paper, the effect of steel fiber content and shape on mechanical strength, toughness, and autogenous and drying shrinkage of UHPC was investigated, and three steel fiber shapes, including straight, corrugated, and hooked fibers, with volume fraction ranging from 0 to 3% were employed.
Abstract: Use of steel fibers in ultra-high performance concrete (UHPC) plays a significant role in enhancing strength and toughness and restraining shrinkage. This paper investigates the effect of steel fiber content and shape on mechanical strength, toughness, and autogenous and drying shrinkage of UHPC. Three steel fiber shapes, including straight, corrugated, and hooked fibers, with volume fraction ranging from 0 to 3% were employed. Compressive, flexural, and fiber-matrix bond strengths were evaluated. A statistical quadratic model and the Composite Theory were employed to predict the flexural strength of UHPC. Test results indicated that the increase in fiber volume can enhance the compressive and flexural strengths of UHPC and reduce shrinkage. The optimum fiber content for strength and shrinkage was found at 2%, beyond which the strength was slightly increased and the shrinkage was slightly decreased. For a given fiber content, the use of hooked fibers was most efficient in improving fiber-matrix bond and flexural strengths and reducing shrinkage. The flexural strengths of UHPC made with various fiber contents and shapes can be predicted using the proposed quadratic model and the Composite Theory. The latter considers the primary parameters affecting performance, including bond strength, matrix properties, and fiber characteristics. Finally, several models were used to simulate autogenous shrinkage behavior of UHPC and optimal models were found.
TL;DR: A systematic review of the state of the art on basalt fibers, basalt-based composite materials and their applications in civil engineering field, by tracing main available evidence and highlighting perspective aspects and open problems is presented in this article.
TL;DR: An easily scalable one-step wet-spinning approach is reported to fabricate highly conductive fibers using hybrid formulations of Ti3 C2 Tx MXene nanosheets and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, demonstrating the potential of MXene-based fiber electrodes and their scalable production for fiber-based energy storage applications.
Abstract: Fiber-shaped supercapacitors (FSCs) are promising energy storage solutions for powering miniaturized or wearable electronics. However, the scalable fabrication of fiber electrodes with high electrical conductivity and excellent energy storage performance for use in FSCs remains a challenge. Here, an easily scalable one-step wet-spinning approach is reported to fabricate highly conductive fibers using hybrid formulations of Ti3 C2 Tx MXene nanosheets and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate. This approach produces fibers with a record conductivity of ≈1489 S cm-1 , which is about five times higher than other reported Ti3 C2 Tx MXene-based fibers (up to ≈290 S cm-1 ). The hybrid fiber at ≈70 wt% MXene shows a high volumetric capacitance (≈614.5 F cm-3 at 5 mV s-1 ) and an excellent rate performance (≈375.2 F cm-3 at 1000 mV s-1 ). When assembled into a free-standing FSC, the energy and power densities of the device reach ≈7.13 Wh cm-3 and ≈8249 mW cm-3 , respectively. The excellent strength and flexibility of the hybrid fibers allow them to be wrapped on a silicone elastomer fiber to achieve an elastic FSC with 96% capacitance retention when cyclically stretched to 100% strain. This work demonstrates the potential of MXene-based fiber electrodes and their scalable production for fiber-based energy storage applications.
TL;DR: In this article, the basic requirements for the rare-earth (RE) ions and host matrix material for obtaining efficient NIR-MIR laser output, a review of the background of processing fundamentals on the fabrication and characterization for newly developed soft optical glass fibers, an outline of the key issues of platinum removal and the dehydration technique, effective doping of RE, and low splicing loss together with the recent theoretical and experimental results.
TL;DR: In this paper, the dimensional stability and dynamic mechanical properties of hybrid composites were analyzed by thermomechanical anlayzer (TMA) and DMA, respectively, and it was concluded that 50:50 weight ratio of bamboo and kenaf fibers is the optimum mixing ratio to enhance both dimensional and mechanical properties.
Abstract: The dimensional stability and dynamic mechanical properties on bamboo (non woven mat)/kenaf (woven mat) hybrid composites was carried out in this study. The hybridization effect of bamboo (B) and kenaf (K) fibers at different weight ratio were studied at B:K:70:30, and B:K:30:70 while maintaining total fiber loading of 40% by weight. The coefficient of thermal expansion (CTE) and dynamic mechanical properties of composites were analyzed by thermomechanical anlayzer (TMA), and dynamic mechanical analyzer (DMA), respectively. Positive hybridization effects were observed on B:K:50:50 hybrid composite with lowest CTE and highest dynamic mechanical properties among all composites. The dimensional stability were strongly influence by the fiber orientation where all composites shows prominent expansion in the transverse fibers direction but relatively low expansion in longitudinal fibers direction. Dynamic mechanical properties in term of complex modulus (E*), storage modulus (E′), loss modulus (E″), Tan delta and Cole-Cole plot were studied. DMA results reveal that B:K:50:50 hybrid composite possess the highest complex modulus due to the strong fiber/matrix interfacial bonding which supported by the coefficient of effectiveness and Cole-Cole plot. Hence, it is concluded that 50:50 weight ratio of bamboo and kenaf fibers is the optimum mixing ratio to enhance both dimensional and dynamic mechanical properties of hybrid composites, and it can be utilized for automotive or building materials applications which demand high dimensional stability and dynamic mechanical properties.
TL;DR: In this paper, a CoFe/HPCF with a filler loading as low as 15% in matrix achieves an extremely strong reflection loss of −−69.1 dB at a thin thickness of 1.6 mm and effective absorption bandwidth reaches 5.2 GHz.
29 May 2019
TL;DR: In this paper, the authors report two different field tests of a continuous-variable QKD system through commercial fiber networks in Xi'an and Guangzhou over distances of 30.02 km (12.48 dB) and 49.85 km (11.62 dB), respectively.
Abstract: The continuous-variable version of quantum key distribution (QKD) offers the advantages (over discrete-variable systems) of higher secret key rates in metropolitan areas as well as the use of standard telecom components that can operate at room temperature. An important step in the real-world adoption of continuous-variable QKD is the deployment of field tests over commercial fibers. Here we report two different field tests of a continuous-variable QKD system through commercial fiber networks in Xi'an and Guangzhou over distances of 30.02 km (12.48 dB) and 49.85 km (11.62 dB), respectively. We achieve secure key rates two orders-of-magnitude higher than previous field test demonstrations. This is achieved by developing a fully automatic control system to create stable excess noise and by applying a rate-adaptive reconciliation protocol to achieve a high reconciliation efficiency with high success probability. Our results pave the way to achieving continuous-variable QKD in a metropolitan setting.
TL;DR: In this article, a novel optic fiber Fabry-Perot interferometer (FPI) based on graphene quantum dots (GQDs) and Polyvinyl Alcohol (PVA) is first proposed for relative humidity (RH) sensing and experimentally demonstrated.
Abstract: A novel optic fiber Fabry-Perot interferometer (FPI) based on graphene quantum dots (GQDs) and Polyvinyl Alcohol (PVA) is first proposed for relative humidity (RH) sensing and experimentally demonstrated. The GQDs-PVA compounds are filled into the hollow core fiber (HCF), which is spliced at the end of a single mode fiber (SMF). The refractive index of GQDs-PVA compounds reduces and the length of the FP cavity elongates with the increase of RH, which will lead the reflective spectrum shift to length wavelength, and the variation can characterize the change of RH values. The humidity environment is generated by different saturated saline solution, and the RH values are calibrated by a moisture meter. Experiment results reveal that the wavelength shift shows good linearity with the RH changing from 13.47%RH to 81.34%RH, and the sensitivity is 117.25 pm/%RH with the linearity relevancy of 0.9983. In addition, reversibility and repeatability experiments are carried out and the mean square deviation of six sets of data is 1.425 × 10−3, which indicates good practical development prospects. Taking the practical application into account, the influence of hydrogen and nitrogen in the air on the sensor is studied before humidity experiment, and the experiment results shows that hydrogen and nitrogen in the air have a negligible effect on the humidity sensor proposed in this paper.
TL;DR: In this paper, the surface of cellulose fibers is successfully modified using the air plasma treatment with the aim of improving the matrix/fiber adhesion, and the modified fibers are studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR).
Abstract: This work deals with provision and characterization of the biopolymer-based composites achieved by incorporation of cellulose fibers as the reinforcement within the glycerol plasticized matrix formed by thermoplastic cornstarch biopolymer. The function of starch-based polymers is limited due to poor mechanical properties. However, it is improved with forming a biocomposite of thermoplastic starch (TPS) as matrix and the cellulose fibers (CF) as reinforcement. The surface of cellulose fibers is successfully modified using the air plasma treatment with the aim of improving the matrix/fiber adhesion. The modified fibers are studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The TPS/CF composites are prepared using high friction and hot compression procedure. Tensile test results and SEM images of the fracture surfaces show significant improvement of adhesion between treated cellulose fibers and TPS matrix. Thermogravimetric analysis shows a considerable decomposition at approximately 250–350 °C. XRD proved the significant increase in crystallinity percentage of composites compared to TPS.
TL;DR: In this paper, the effects of different geometric parameters have on the tensile properties of 3D printed composites manufactured by fused filament fabrication (FFF) out of continuous and chopped carbon fiber reinforcement.
Abstract: The use of additive manufacturing (AM) is rapidly expanding in many industries mostly because of the flexibility to manufacture complex geometries. Recently, a family of technologies that produce fiber reinforced components has been introduced, widening the options available to designers. AM fiber reinforced composites are characterized by the fact that process related parameters such as the amount of reinforcement fiber, or printing architecture, significantly affect the tensile properties of final parts. To find optimal structures using new AM technologies, guidelines for the design of 3D printed composite parts are needed. This paper presents an evaluation of the effects that different geometric parameters have on the tensile properties of 3D printed composites manufactured by fused filament fabrication (FFF) out of continuous and chopped carbon fiber reinforcement. Parameters such as infill density and infill patterns of chopped composite material, as well as fiber volume fraction and printing architecture of continuous fiber reinforcement (CFR) composites are varied. The effect of the location of the initial deposit point of reinforcement fibers on the tensile properties of the test specimens is studied. Also, the effect that the fiber deposition pattern has on tensile performance is quantified. Considering the geometric parameters that were studied, a variation of the Rule of Mixtures (ROM) that provides a way to estimate the elastic modulus of a 3D printed composite is proposed. Findings may be used by designers to define the best construction parameters for 3D printed composite parts.
TL;DR: A novel highly sensitive wearable strain sensor based on a highly stretchable multi-walled carbon nanotube (MWCNT)/Thermoplastic Polyurethane (TPU) fiber obtained via a wet spinning process may open a new avenue for the fabrication of next-generation stretchable textile-based strain sensors.
Abstract: Here, we report a novel highly sensitive wearable strain sensor based on a highly stretchable multi-walled carbon nanotube (MWCNT)/Thermoplastic Polyurethane (TPU) fiber obtained via a wet spinning process. The MWCNT/TPU fiber showed the highest tensile strength and ultra-high sensitivity with a gauge factor (GF) of approximately 2800 in the strain range of 5–100%. Due to its high strain sensitivity of conductivity, this CNT-reinforced composite fiber was able to be used to monitor the weight and shape of an object based on the 2D mapping of resistance changes. Moreover, the composite fiber was able to be stitched onto a highly stretchable elastic bandage using a sewing machine to produce a wearable strain sensor for the detection of diverse human motions. We also demonstrated the detection of finger motion by fabricating a smart glove at the joints. Due to its scalable production process, high stretchability and ultrasensitivity, the MWCNT/TPU fiber may open a new avenue for the fabrication of next-generation stretchable textile-based strain sensors.
TL;DR: In the natural seawater, SSUP fiber achieved a breakthrough uranium extraction capacity of 12.33 mg g-1 with an ultrashort equilibration time of 3.5 days, suggesting that SSUP Fiber might be a very promising adsorbent for uranium extraction from thenatural seawater.
Abstract: For the practical extraction of uranium from seawater, adsorbents with high adsorption capacity, fast equilibrium rate, high selectivity, and long service life are needed. Herein, a chimeric spidroin-based super uranyl-binding protein (SSUP) fiber was designed by fusing the gene of super uranyl-binding protein (SUP) with the gene of spidroin. SUP endowed the SSUP fiber with high affinity and selectivity to uranium, and spidroin gave the SSUP fiber with high mechanical strength and high reusability. The wet SSUP fiber is a water-rich hydrogel-like structure, which provided abundant hydrophilic intermolecular space for the entrance of uranyl ions, and could accelerate the rate for uranium adsorption. In seawater, the SSUP fiber achieved a breakthrough uranium extraction capacity of 12.33 mg g-1 with an ultrashort equilibration time of 3.5 days, suggesting that SSUP fiber might be a promising adsorbent for uranium extraction from the natural seawater.
TL;DR: In this article, the state of the art of the impact resistance of ordinary fiber-reinforced concretes (FRCs) containing various fibers is reviewed, and various types of impact test methods are addressed as well as some concerns about them based on extensive literature reviews and our perspective.
Abstract: This paper reviews the state of the art of the impact resistance of ordinary fiber-reinforced concretes (FRCs) containing various fibers. First, various types of impact test methods that are current available are addressed as well as some concerns about them based on extensive literature reviews and our perspective. Then, common properties of FRCs under impact loading regardless of fiber type, such as the reasons for their enhanced strength under impact, the effect of size on impact resistance, and several factors (i.e., matrix strength, loading conditions, and fiber existence) that influence strain-rate sensitivity, are discussed. Furthermore, the comprehensive impact resistances of FRCs with various fibers (i.e., steel, polymeric, carbon, basalt, natural, and hybrid fibers) are investigated under different loading conditions. After summarizing the impact properties of FRCs with various fibers, the comparative impact resistance of FRCs according to the fiber type is evaluated to determine which type gives the best improvement of impact resistance. Lastly, the effect of supplementary cementitious materials (SCMs), i.e., fly ash, silica fume, and slag, on the impact resistance of FRCs is examined, and some combinations of SCM and fiber types that lead to enhanced impact resistance are suggested.
TL;DR: In this article, the authors have shown that fiber type was very effective on the mechanical properties of composites and that molded fiber production method had a very promising future for the development of natural fiber reinforced composites.
Abstract: The aim of this research is the production of epoxy resin composites reinforced by birch, palm, and eucalyptus fibers with resin transfer molding technique and molded fiber production technique combination. The tensile stress of birch, palm, and eucalyptus reinforced epoxy composites were determined as 29.53, 42.24, and 45.28 MPa, respectively. Bending stress of birch, palm and eucalyptus reinforced epoxy composites were found as 58.83, 68.58, and 79.92 MPa, respectively. The birch epoxy composite had 0.105 J impact energy while palm and eucalyptus epoxy composites were determined as 0.130 and 0.124 J, respectively. It is clearly observed that fiber type was very effective on the mechanical properties of composites. The results of studies showed that molded fiber production method had a very promising future for the development of natural fiber reinforced composites.
TL;DR: In this paper, the synergistic effect of combining macro polypropylene (PP) fiber and rubberized concrete was evaluated based on mechanical and durability performance, as well as microstructure.
TL;DR: In this paper, the mechanical, hygral, and interfacial strength of continuous bamboo fiber reinforced epoxy composites were investigated, and the results showed that the tensile strength and Young's modulus of the composite increase with the decrease of the bamboo fiber diameter.
Abstract: This study is to investigate the mechanical, hygral, and interfacial strength of continuous bamboo fiber reinforced epoxy composites. The untreated and alkali-treated continuous bamboo fibers were prepared from cutting the nature bamboo culm. The basic characteristics of the bamboo fibers, such as density, equivalent diameter, and tensile properties were experimentally measured. The bamboo fiber reinforced epoxy (BF/EP) composites were fabricated by the resin transfer molding (RTM) process with the resulting fiber volume fraction about 42%. The strength of bamboo fiber was found to decrease with the alkaline treatment. However, alkali-treated bamboo fiber reinforced epoxy composites acquired better tensile strength than those with untreated bamboo fibers. The untreated bamboo fiber was believed to have weak interface with the epoxy resin, which was verified by the subsequent interface strength tests. The size effect of bamboo fibers on the tensile properties of the BF/EP composites were also studied. The results showed that the tensile strength and Young's modulus of the composite increase with the decrease of the bamboo fiber diameter. For the hygrothermal aging test, BF/EP composites are highly sensitive to moisture absorption, and the moisture has a detrimental effect on the mechanical properties of the BF/EP composite.
TL;DR: In this article, the effect of silica fume content, ranging from 0 to 25%, by mass of cementitious materials, on rheological, fiber-matrix bond, and mechanical properties of non-fibrous UHPC matrix and uHPC made with 2% micro-steel fibers was investigated.