Effect Of Fiber Addition Research Articles

The effect of fibers addition on the microstructure and mechanical properties of ZrO2 fibers toughened Al2O3/ZrO2 (Y2O3) solidified ceramics

Fiber toughening is considered an effective way to strengthen the toughness of traditional sintered ceramics. Herein, ZrO2 fibers toughened Al2O3/ZrO2 (Y2O3) directionally solidified eutectic ceramics (DSECs) were prepared with the high-frequency induction heating zone melting (IHZM). The effects of ZrO2 fibers content on the phase composition, microstructure, and mechanical properties of the eutectic ceramics were studied. The findings revealed that DSEC consists of α-Al2O3 and ZrO2 phases, presents a typical colony microstructure. The phase spacing in the colony decreased with the addition of fibers, reaching a minimum value of 1.99 ± 0.25 μm at 20 wt%, which was nearly 40 % lower than that without the fiber’s addition. The hardness of DSEC increased gradually with the addition of fibers. Its highest value reaches 18.42 ± 0.55 GPa when the fiber content is 20 %. The fracture toughness of DSEC first increased and then decreased, reaching a maximum of 5.43 ± 0.22 MPa·m1/2 at 10 wt%, which was 1.5 times higher than that of the fibers-free eutectic ceramic. The improvement of fracture toughness was primarily due to the fibers toughening. In addition, the crack deflection, pinning, bridging, and branching had a significant inhibitory effect on the crack propagation.

Effect of fiber addition on strength and toughness of rubberized concretes

In this paper, an experimental study was conducted to examine the static and dynamic behaviors of rubberized fiber-reinforced concrete (RFRC). Crumb rubber was partially replaced from sand at volume fractions of 0%, 5%, 10%, 15%, and 20%. Steel fibers (SFs) with fiber volume fractions (Vf%) of 0%, 0.5%, 1%, and 1.5% were used for the production of FRCs, while polypropylene fiber (PPF) with Vf% = 0.4% was adopted to produce others FRCs. A combination of 0.4% PPF and 1% SF was used for hybrid FRC. The static properties were evaluated through compression, indirect tension, and flexural tests. However, the drop weight impact test was conducted to assess the dynamic property by estimating the impact energy. It was observed that the replacement of sand with rubber reduced all mechanical properties of concrete. In the case of RFRC, a reduction in compressive strength, compared to samples without fibers, was noted, and this reduction increased with higher Vf%. Both toughness indices and fracture energy were affected slightly by increasing rubber percentages while markedly increased with higher Vf%. However, adding rubber and/or fibers enhanced the impact energy of concrete.

Feasibility of Strengthening Sandy Soils Using Industry Waste as Geo-Fiber

Abstract Re-using waste generated from daily domestic usage to improve weak soils such as dune sand gives a profitable solution to both environment and the construction sector. In this paper, weak sandy soil was modified with two types of fibers derived from daily domestic use. Plastic bottle waste fiber and tainted polypropylene sediment filter fiber were embedded in the sandy soil with a rate of (0.5%,1%,1.5%, and 2%) by weight of dry soil. Toward this, the direct shear test was conducted to confirm the optimum fiber content and evaluate other parameters such as shear strength, normalized ultimate shear strength, angle of internal friction, and adhesion. The results showed that the 1.5% fiber content showed higher values of angle of internal friction and the normalized ultimate shear strength for both types of fibers. The reinforcement with plastic bottle waste fiber and tainted polypropylene sediment filter fiber enhanced the shear strength parameters and normalized ultimate shear strength. Significant improvement was noticed in the adhesion value with the addition of 2% of tainted polypropylene sediment filter fiber. finally, the effect of fiber addition on the Mohr-coulomb failure envelope was discussed.

Effects of glass fiber usage on fracture energy and mechanical behavior of concrete: An experimental approach

In this study, the fracture and mechanical behavior of glass fiber reinforced concrete (GFRC) are investigated comparatively. For this purpose, three-point bending tests were carried out on notched beams produced using GFRC with 1, 2, and 3 kg/m3 fiber contents and the dimension of 6, 12, and 24 mm to determine the fracture energy. Fracture energy values of the GFRC specimens were calculated by analyzing load versus crack mouth opening displacement (CMOD) curves. Compressive strength was determined using cube samples with the dimension of 150x150mm. Tensile strength and Modulus of elasticity were determined using notched beams with the dimensions of 48010050 mm. Also, notched beams were produced and tested in accordance with RILEM recommendations. In addition, microstructural analyses were performed based on Scanning Electron Microscopy and Energy-Dispersive X-ray Spectroscopy examinations. The results showed that the effects of fiber contents on fracture energy were very significant. However, the effect of fiber addition on the compressive strength and modulus of elasticity values was not significant.

Effects of fibre addition and processing on the stability, rheology and in vitro gastric digestion of whey protein-xanthan gum stabilised emulsions with high oil phase

The aim of work was to structure and characterise the high rapeseed oil emulsions stabilised by xanthan gum rich whey protein with an inclusion of commercially available added fibre (Vitacel HF0010 plus) as an additional stabiliser. The manufactured emulsions were also tested whether they can re-build the emulsion property after drying, water addition and re-emulsification. The emulsions with a ratio of 60/40 for rapeseed oil to water phase were obtained with a fibre inclusion at 0.25, 0.50 and 1.00% using a high shear homogenisation. Drying processing, rehydration and re-emulsification only led to re-build emulsion structure with 0.50 and 1.00% fibre. After re-emulsification, some fibre occurred as insoluble particles and were allocated at the oil-water interface or continuous phase of emulsion. Interestingly, processed sample with 1.00% fibre had the greatest instability when subjected to in vitro gastric digestion assay. All primary emulsions and processed emulsions with 0.50 and 1.00% fibre, were stable against coalescence with no oil loss and resulted in almost identical droplet size after a day 30 of storage at 4(±1)°C. All the structured emulsions showed shear-thinning behaviour. The fabricated emulsions showed a feature of regaining emulsion structure, which extend their applications in food formulation as clean label emulsions.

Effect of fibers addition on mechanical properties of eco-friendly phosphogypsum-based composite at high temperatures

In this study, the mechanical properties of an eco-friendly hemihydrate phosphogypsum-based composite (HPGC) added with basalt, glass, and PVA fibers upon exposure to high temperatures (250°C, 450°C, 650°C, and 850°C) were investigated. The fibers content (0%-1.35 vol%) did not have a significant effect on compressive strength at ambient temperature, while the flexural strength of HPGC was enhanced optimally at 1.0% fiber volume. For the investigation at high temperatures, the fiber inclusion could effectively reduce the cracks but increased the mass loss of HPGC. Compared to other fiber types, HPGC with PVA fiber, which did not melt at 250°C, exhibited the highest compressive strength and flexural strength (32.59 MPa and 10.56 MPa, respectively) at the temperature of 250°C but had a greater strength reduction between temperatures of 450°C and 850°C. At 850°C, HPGC with basalt fiber exhibited higher flexural strength than HPGC added with other fibers, and with 133.3% higher flexural strength than HPGC without fiber. The microstructural investigation confirmed that the changes of calcium sulfate forms (dihydrate to hemihydrate and anhydrite) and ettringite in the matrix contributed to the strength loss of all HPGC mixtures at high temperatures, while the existence of basalt fiber-matrix bond allows the HPGC added with basalt fibers to have the best residual properties at 850°C compared to the other mixes.

Study on Dynamic Splitting Properties of S-PP Hybrid Fiber Concrete after High Temperatures

To study the dynamic tensile mechanical properties of steel polypropylene hybrid fiber reinforced concrete (SP-HFRC) after high temperature, split Hopkinson pressure bar (SHPB) dynamic splitting tests were carried out, and the optimal fiber content combination was obtained. With the plain concrete (PC) as the control, the effects of fiber addition on energy dissipation and failure forms of concrete specimens after high temperatures were analyzed. LS-DYNA software was used to simulate the dynamic splitting test. The results show that the splitting strength of specimens increases first and then deteriorates with the increase of temperature. After high temperatures, HFRC has a positive and negative fiber hybrid effect. Among the studied fiber mixture combinations, S1PP0.2 (1 vol% steel fiber + 0.2 vol% polypropylene fiber) concrete has the best splitting resistance. Compared with PC, the splitting strength increases by 106.8% at 25 °C and 128.2% at 800 °C. From the perspective of energy, we can conclude that adding hybrid fiber can significantly improve the dynamic splitting and tensile toughness of concrete after high temperatures, and defining damage variables can better characterize the damage degree of concrete. PC cracks seriously after high temperatures, while S1PP0.2 concrete cracks but does not disperse at 800 °C, showing ductile failure characteristics. By modifying some parameters of the HJC model, the state of high-temperature concrete mechanical properties can be better characterized after deterioration. The simulated failure process shows an excellent agreement with the experimental results.

Effect of fibre addition on the static and dynamic compressive properties of ambient-cured geopolymer concrete

This paper presents an experimental study on the static and dynamic compressive properties of ambient-cured fibre reinforced geopolymer concrete (FRGPC) containing mono steel, mono polypropylene (PP) or hybrid steel-PP fibres. A Split Hopkinson Pressure Bar (SHPB) was used to carry out dynamic compressive tests under different strain rates up to 130.5 s−1. The effects of fibre addition on static compressive strength, splitting tensile strength, dynamic failure process and damage mode, dynamic compressive strength, specific energy absorption and dynamic increase factor (DIF) were investigated and analysed. The results revealed mono steel fibre as the most effective in improving static compressive and splitting tensile strengths, which increased by 21.92% and 21.05% respectively, compared to plain geopolymer concrete (GPC). The dynamic compressive strength of both plain GPC and FRGPC increased with the increase of strain rate. There is a positive relationship between DIFs of compressive strengths and strain rates for all GPC and FRGPC samples. The samples containing mono PP fibres showed the most strain rate sensitivity with respect to compressive strengths and specific energy absorption within the tested strain rates. Furthermore, empirical formulae are proposed accordingly to predict the DIFs and specific energy absorption of ambient-cured GPC and FRGPC.

Macro and micro polypropylene fiber effect on reinforced concrete beams with insufficient lap splice length

For longer spans of reinforced concrete elements, design codes dictate the use of sufficient lap splice length. Insufficient lap splice length decreases the flexural strength and ductility of reinforced concrete (RC) beams, while fiber addition improves their load-carrying capacity, ductility, and durability. The main purpose of this study was to examine the effects of micro and macro fibers on the lap splice length of RC beams. In this regard, the effect of fiber addition on RC beams having insufficient lap splice length under bending test has been studied in detail. Mixtures were prepared with different fiber ratios (0.5% micro polypropylene (PP), 0.25% micro polypropylene-0.25% macro-synthetic polypropylene (MS), 0.5% macro-synthetic polypropylene by volume of concrete) and performed on half-scale RC beams with various lap splice lengths. In beams with insufficient lap splice length, the addition of MS fiber improved the energy absorption capacity at around 30% and the load-carrying capacity at about 18%, while the effect of PP was limited. Damage analysis of the beam illustrates that MS fiber addition on RC beams inhibits crack propagation and improves load-carrying capacity.

Mikronize edilmiş şeker pancarı besinsel lifinin buğday hamuru ve ekmek özellikleri üzerine etkileri

The aim of this study is to determine the effect of sugar beet fiber, micronized by high pressure homogenization, addition on the rheological and textural properties of wheat dough and the quality parameters of bread. The micronized and unmicronized sugar beet fibers were used in the bread formulation and they were incorporated into flour at levels of 2, 4, 6, 8, and 10%. The addition of sugar beet fiber increased the storage modulus (G′) and loss modulus (G″) values and led to more solid-like and elastic bread dough. Also, the hardness values of bread dough increased while the gumminess and adhesiveness values didn’t change significantly. The addition of sugar beet fiber significantly decreased the volume of bread samples (P ˂0.05). The effect of fiber addition on the textural properties of bread was determined and it was observed that the hardness and chewiness of bread samples increased while the cohesiveness and springiness parameters didn’t change. Sugar beet fiber addition significantly decreased the lightness (L) values and increased the redness (a) values of the crumbs. According to the results of sensory analysis, all bread samples that contain sugar beet fiber were evaluated as acceptable by the panelists. The bread samples that contain unmicronized sugar beet fiber at a 4% level and micronized sugar beet fiber at a 2% level got similar scores to the control bread. Micronization by high pressure homogenization has developed functional properties of sugar beet fiber and it is understood that it could be used in various foods.

Effect of Dietary Fiber and Thermal Conditions on Rice Bran Wax-Based Structured Edible Oils.

In this work, extra-virgin olive oil (EVO)- and sunflower oil (SFO)-based oleogels were structured using rice bran wax (RBW) at 10% by weight (w/w). Bamboo fiber milled with 40 (BF40), 90 (BF90) and 150 (BF150) µm of average size was added as a structuring agent. The effect of fiber addition and cooling temperature (0, 4, and 25 °C) on thermal and structural parameters of achieved gels was assessed by rheological (both in rotational and oscillatory mode), texture, and differential scanning calorimetry tests. Oleogelation modified the rheological behavior of EVO and SFO, thus shifting from a Newtonian trend typical of oils to a pseudoplastic non-Newtonian behavior in gels. Moreover, oleogels behaved as solid-like systems with G′ > G″, regardless of the applied condition. All samples exhibit a thermal-reversible behavior, even though the presence of hysteresis suggests a partial reduction in structural properties under stress. Decreasing in cooling temperature negatively contributed to network formation, despite being partially recovered by low-granulometry fiber addition. The latter dramatically improved either textural, rheological, or stability parameters of gels, as compared with only edible oil-based systems. Finally, wax/gel compatibility affected the crystallization enthalpy and final product stability (gel strength) due to different gelator–gelator and gelator–solvent interactions.

The Investigation of Mechanical Properties of Polypropylene Fiber-Reinforced Composites Produced With the Use of Alternative Wastes

Various studies on the disposal or storage of the wastes generated due to mining activities have been carried out until today. With the developing technology, the use of alternative products instead of aggregates in Composite and the effect of fiber addition were investigated. The most common of these studies is the bending strength tests on the beam sample. In this study, solid wastes generated by mining operations were used instead of aggregate used in Composite. Beam samples were poured with the dimensions of 40×40×160 mm by adding 4-6 kg/m3 polypropylene fiber to the mixture obtained by using these solid wastes; then, its effects on ultrasonic pulse velocity test, tensile test, and compressive strength tests were conducted. According to the results of these tests, it was found that the fibers had a positive effect on compressive strength and bending strength. Also, it was found that water absorption rates and densities did not have an effect, while the ultrasonic pulse velocity decreased with increasing fiber content.

Development of modified polyacrylonitrile fibers for improving tribological performance characteristics of thermoplastic polyurethane material in water‐lubricated sliding bearings

Thermoplastic polyurethane (TPU) is one of the most popular marine bearing materials because of its excellent characteristics. However, severe wear often occurs under some extreme conditions. In order to improve the service life of bearing material, this work introduced the polyacrylonitrile (PAN) fiber as a reinforcement material to further enhance TPU tribological properties. Considering that the bearing material does not process self‐lubricating or cannot form a stable water film under some working conditions, the PAN fiber was hydrophilically modified to alleviate this problem. The effects of fiber addition, operation speed, and applied load on the tribological properties of the composites were examined by using a tribo‐tester. The friction coefficient of the samples, the surface morphology after rubbing, and the wear loss, and so on, were also comprehensively analyzed. It was found that the friction coefficient of 30% modified PAN fiber at 500 r/min and 0.8 MPa load was 0.08, and its friction coefficient was 81.8% lower than the pure sample under the same working condition, this is mainly due to the high hydrophilicity of the modified PAN fiber, which makes it easier to form a water film between the composite material and the copper disc. Furthermore, adhesive wear occurred in unmodified samples, while modified samples contained abrasive wear. This new material modification method and design idea can be used for improving the performance of water‐lubricated bearing materials.

Effect of macro-synthetic structural fibers on the flexural behavior of concrete beams reinforced with different ratios of GFRP bars

Fiber reinforced polymer (FRP) bars are increasingly used as internal reinforcement in concrete structures for mitigating the corrosion problems associated with steel reinforcement. However, its wide spread use in construction is limited by the parameters such as lack of awareness/usage, brittle failure mode, high initial cost, availability of comprehensive guidelines and test data on its long term effectiveness. The use of macro-synthetic structural fibers is explored in this study for improving the post-cracking, and deformability characteristics of glass FRP (GFRP) reinforced concrete beams. In total, eighteen full-scale RC beams with and without structural synthetic fibers are tested under flexure. The test specimens include: (i) control beams with steel reinforcement, (ii) GFRP bar RC beams without macro-synthetic fibers, and (iii) GFRP RC beams with 0.35%, 0.7%, and 1.0% volume of macro-synthetic fibers. The effect of fiber addition on cracking, stiffness and deformability characteristics of GFRP RC beams with different longitudinal reinforcement ratios (0.7% and 2.0%) is investigated. Experimental results reveal that the addition of fibers significantly improved the post-cracking response. Moreover, the crack widths reduced significantly at service loads with the increase in fiber dosage. Addition of 1% fibers helps in enhancing the deformability of GFRP RC beams and converts the failure from brittle flexure-shear to ductile flexure mode with higher pseudo-ductility. Analytical calculations of deflections showed a close correlation with the test results.

Effects of fiber addition on performance of high-performance alkali activated slag concrete mixes: An experimental evaluation

There is an ever-increasing awareness on issues connected with emission of high amounts of greenhouse gases from various industries, including that from the concrete construction industry. Performances of alternative binder systems including geopolymers and alkali activated slag concretes are being investigated in this context. There is again a continuous drive to enhance their performances, both when green and on getting hardened and so also, simultaneous efforts are being made to take advantage of all the various fast-track, state-of-art construction technologies, leading to efficient, eco-friendly and economical infrastructure projects. The present authors have developed and evaluated a new set of such alkali activated slag concrete mixes having self-compacting property, along with higher mechanical properties (hereafter referred to as HPAASC mixes) using three industrial by-products, all obtained from iron and steel industry. While these HPAASC mixes have higher compressive strengths (in the range of 70–90 MPa), reasonable split and flexural strengths and are self-compacting, they continue to be brittle just as other high strength concrete mixes. In order to improve their cracking behaviour during failure, either under mechanical loads or on exposure to higher temperatures, addition of increasing amounts of steel fibers in HPAASC mixes is contemplated. Hence in the present study, the attempt is to study the effect of incorporation of fibers (within a small range of 0.4 − 0.8%) in the new class of high-performance, fibre reinforced. Self-compacting alkali-activated slag concrete mixes – (referred to as HFSASC hereafter). The present study evaluates the properties such as flow ability, compressive strength and flexural toughness performances for these mixes. Results in the present study indicate that, while all the HFSASC mixes exhibit satisfactory passing and flowing abilities specified as per EFNARC standards for self-compacting mixes, they exhibit enhanced toughness characteristics too.

Relationship between microstructure and performance of polypropylene fibre reinforced cement composites subjected to elevated temperature

This article presents the investigation on mechanical and transport properties of polypropylene (PP) fibre reinforced cement composites with varying fibre volume (0.05–0.30%). Fresh property of the fibre reinforced concrete was evaluated through the flow table test, while hardened properties including compressive strength (1, 3, 7 and 28-day), and modified flexural strength, ultrasonic pulse velocity and water absorption were assessed at the 28-day. The effects of fibre addition on mechanical properties were evaluated at room temperature and 200 °C. Microstructural characterizations were performed using field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray spectroscopy (EDX). Micrographs of the failed PP fibre reinforced composites indicated that the increase in flexural strength at room temperature was attributed to the crack bridging and fibre debonding at the fibre/matrix interface. Higher water absorption value was achieved for PP reinforced composites subjected to elevated temperature compared to control mortar. FESEM/EDX analyses on the elevated temperature samples indicated that the increment was due to the growing of macro-pores from the empty space left behind by fibre settlement. In conclusion, the addition of PP fibres in the cement mortar adversely affect the strength when the composite is subjected to elevated temperature, but resulted in improved durability.

Ethylene propylene diene monomer rubber‐based heat shielding materials for solid rocket motor: Impact of Kevlar fiber reinforcement on the thermal and mechanical properties

This work scrutinizes the utilization of ethylene propylene diene monomer rubber matrix (EPDM) with an embodiment of aramid fiber for the heat shielding applications in solid rocket motor (SRM). Aramid fibers are aromatic poly‐paraphenylene terephthalamide, here deployed are Kevlar fibers (KF). However, the literature that encompasses the thermal and mechanical behavior with the fiber loading is reported nowhere else. The effect of fiber addition on the surface morphology and density was thoroughly studied, and it revealed that the EHSMs were of lower density to act as an efficient payload for the SRM. In this regard, the thermal conductivity, heat capacity, thermal diffusivity, fire behavior, and mechanical properties of the EPDM/KF‐based EHSMs were explored. The results revealed that the EHSMs are thermally insulating and thermally stable material with balanced mechanical properties that can engender the thermal and mechanical strains of the rocket motor. Furthermore, other analytical techniques such as scanning electron microscopy and energy dispersive X‐ray spectroscopy have been exploited to monitor the performance of the char residues of the EHSM to delineate its performance in the fire atmosphere.

Characterization of Natural Composites Fabricated from Abutilon-Fiber-Reinforced Poly (Lactic Acid)

In recent decades, natural-fiber-reinforced poly (lactic acid) (PLA) composites have received a great deal of attention. In this study, biocomposites of poly (lactic acid) and abutilon fibers are prepared by using melt blending and an extruder. The effects of fiber additions on rheological, thermomechanical, thermal, and morphological properties are investigated using a rheometer, dynamic mechanical analysis (DMA), differential scanning calorimeter (DSC), TGA, and SEM, respectively. The DSC results indicate that the fibers acted as a nucleating agent, which led to enhancing the crystallization of PLA. The results also reveal that the thermal stability of PLA was improved by abutilon fibers. Moreover, higher values of storage modulus are observed, which are attributed to strong interfacial adhesion. In addition, thetan delta isreduced upon the addition of fiber content into the PLA matrix, which restricts the mobility of PLA polymer molecules in the presence of the fibers. The improvement of the properties and energy absorption capabilities of such biocomposites signifies the great potential of abutilon fibers as reinforcement in green composites.

PP-coir Composites (PPCC): Fabrication and Study of Flexural Properties

Today we are more concern about the environment. Synthetic polymers are the most responsible pollutant for environmental pollution. Good replacing agents for the synthetic polymers are the natural polymer. That is why the uses of natural fiber reinforced composites are increasing day-by-day. In this research natural polymer coir fiber was used as the reinforcing agent with the synthetic polymer polypropylene. PP-coir composites were fabricated using a simple hot press molding method. The prepared composites were characterized by the density, tensile, and flexural properties. The effect of fiber addition on some physical and mechanical properties was evaluated. The density increases with the increase of fiber addition. The tensile strength of fabricated product increases with the increase of fiber addition up to 10% (wt.) and then decreases continuously. The elongation of fabricated product decreases with the increase of fiber addition continuously. The changes in the mechanical properties were broadly related to the accompanying interfacial bonding of PP- coir composites (PPCC). It revealed that the introduction of short coir fiber led to a slightly improved thermo oxidative stability of PP- Coir composites. The flexural strain of fabricated product decreases continuously with the increase of fiber addition. But here untreated fiber reinforced composites show higher strain than that of treated fiber reinforced composites.

HDPE- Coir composites–fabrication, process parameters and properties

The composites of biodegradable high density polypropylene (HDPE) reinforced with short coir fiber were prepared by melt mixing followed by hot press molding. The effect of fiber addition on some physical and mechanical properties was evaluated. Different process parameters (e.g. mixing time, heating temperature and time, cooling time etc.) were established for good sample preparation The effects of fiber addition on some physical and mechanical properties were evaluated. The mechanical properties were studied via Universal Testing Machine (UTM). The density was increased with the increase of fiber addition. The tensile strength (TS) of fabricated product increased with the increase of fiber addition up to 10% (by wt.) and then decreased continuously. The elongation of fabricated composites was decreased with the increase of fiber addition continuously. The changes in the mechanical properties were broadly related to the accompanying interfacial bonding of HDPE coir composites (HDPECC). To observe the hydrophilicity of the prepared composites was evaluated by the water uptake properties. The interfacial bonding of the fiber and matrix of the coir fiber reinforced composites was studied via scanning electron microscope. It revealed that the introduction of short coir fiber led to a slightly improved mechanical stability of PP- Coir composites.