Use Of Glass Fibers Research Articles

Alkali-resistant glass fiber high strength concrete and its durability parameters

The use of glass fiber in ordinary and standard concrete had been extensively investigated. Not much research work had been done on high-strength concrete with glass fiber. This research work deals with experimental investigations on the performance of alkali-resistant glass fiber of 12 mm standard cut length with varying percentages of 0.8, 1.2, 1.6, 2.0, and 2.4 by weight of cement in high-strength concrete. Investigations are conducted on fresh concrete for workability and hardened concrete specimens for compressive and tensile strengths, NDT, percent voids and sorptivity after 7 and 28 days of normal curing. It has been observed that the effect of the dose of the fiber on the workability of high strength concrete is similar to its effect on ordinary and standard grade concretes but different for compressive strength. The lower percentage of glass fiber significantly enhances strains without contributing to strength. The higher percentage of the fiber decreases the strength with a lesser increase in corresponding strain than GFRC with a lower percentage of the fiber. The percentage of the fiber which enhances its compressive strength imparts maximum tensile strength to the fibrous concrete after 28 days by 12.24, 13.13, 17.31, 15.82, and 11.94% for the fiber content of 0.8, 1.2, 1.6, 2.0, and 2.4% than non-fibrous concrete. The addition of glass fiber ranging from 0.8% to 2.4% increases the cumulative rate of water absorption and coefficient of sorptivity by 50.0, 54.9, 69.8, 92.1, and 90.6%, and 12.9, 36.3, 34.7, 55.6, and 95.1%, respectively as compared to non-fibrous concrete.

Comparative evaluation of fracture resistance of endodontically treated premolars with one remaining cavity wall restored using different techniques and materials: An in vitro study

Introduction: This study was aimed to evaluate and compare the effectiveness of conventional posterior composites, and short fiber-reinforced composites with and without the use of glass fiber post (GFP) and polyethylene fiber post on fracture strength of endodontically treated maxillary premolar teeth. Materials and Methods: Root canal treatment was performed on the sixty extracted maxillary premolars followed by mesio-occluso-distal cavity preparation and removal of the lingual wall. The teeth were randomized into six groups (A1, A2, A3; B1, B2, and B3). In Group A, a conventional posterior composite was used as a core material, and in Group B, short fiber-reinforced composite was used. Groups A and B were divided according to the post systems used. In Groups A1 and B1, 3 mm deep cavities were prepared in the palatal canal and restored with respective core materials. In Groups A2 and B2 GFP were placed in 10 mm post space prepared in the palatal canal and restored with respective core material. While in Groups A3 and B3 polyethylene, fiber post was placed, followed by core build-up with respective core materials. Samples were subjected to fracture resistance testing in the Universal testing machine, and the fractured samples were inspected in stereomicroscope under 20× for identifying fracture patterns. The data were analyzed using one-way ANOVA, followed by post hoc Tukey's test. The failure pattern was analyzed using the Chi-square test. Results: Higher fracture resistance values were seen with groups restored with the post as compared to groups restored without post, but the difference was not statistically significant (P > 0.05). The short fiber-reinforced composite showed higher resistance values than the conventional composite (P 0.05). The use of post resulted in a significantly higher number of favorable fracture of the teeth (P Conclusion: The use of post did not have a profound effect on the fracture resistance but had a positive effect on failure patterns in teeth with one remaining wall. In root canal treated teeth with one wall remaining, the use of either post with short fiber reinforced composite is recommended.

Effect of glass fiber on the properties of expansive soil and its utilization as subgrade reinforcement in pavement applications

The purpose of this study is to investigate the use of glass fibers as discrete random reinforcement in expansive subgrade soil to improve its strength for pavement application. The fiber content varied between 0.25 % and 1.0 % by weight of dry soil. A series of free swell, Unconfined Compressive Strength (UCS), Indirect Tensile Strength (ITS), and California Bearing Ratio (CBR) tests were conducted on unreinforced and reinforced expansive soil specimens. In addition, the effect of the inclusion of the fiber on the design and performance of flexible pavement was evaluated using the Mechanistic-Empirical Pavement Design Guide (MEPDG). The test results showed that the inclusion of glass fibers in subgrade soil significantly increases the UCS, ITS, and CBR, and decreases the free swell values. MEPDG analyses showed that the glass fibers could be a suitable reinforcement for the subgrade layer for pavement construction. A significant decrease in pavement thickness can be achieved by the inclusion of glass fibers in subgrade stabilization.

Enhanced CW Lasing and Q‐Switched Pulse Generation Enabled by Tm3+‐Doped Glass Ceramic Fibers

AbstractFiber lasers, owing to the high beam quality and super robustness, are widely used in fields from optical communications, fiber sensing, biomedicine to material processing. The use of glass fibers as the gain medium has, however, posed a strong obstacle for improving efficiency and, especially, achieving efficient lasing action in the mid‐infrared (MIR) region, because of the relatively large nonradiative energy loss. Here, the fabrication of a Tm3+‐doped tellurate glass‐ceramic (GC) fiber is demonstrated, which enables enhanced lasing action at ≈2 µm. Compared with the as‐prepared fiber, the optical conversion efficiency of GC fiber is increased from 8.8% to 14.1%. The microstructure and spectral characterization analyses suggest that the improvement of the laser performance in GC fiber is induced by the significant change of the local environment surrounding Tm3+ ions due to the formation of nanocrystals within the glass fibers. Moreover, the developed GC fiber also enables Q‐switched pulsed laser output at ≈2 µm with a pulse energy of 3.2 J and pulse width of 4.1 ns. The results demonstrated here may have strong implications in the development of MIR fiber lasers and the applications of GC fibers in MIR photonics.

Effects of thermal cycles on microstructural and functional properties of nano treated clayey soil

Thermal cycles can remarkably alter the geological and resistance properties of soil beneath structures. This research examined the effect of simultaneous use of glass fiber and nano-SiO2 on strength properties of low plasticity clay (CL) under various thermal cycles. The contents of glass fiber and nano-SiO2 were chosen 1.5%, 2.5%, 3.5% and 0.5%, 1.0%, 1.5% of the soil dry weight, respectively. The strength properties of natural soil and treated clay were estimated via unconfined compression and direct shear tests. Further, the images of scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) tests were used to assess the microstructure of soil affected by freeze and thaw periods. The obtained results indicated that different mixtures of nano-SiO2 and glass fiber can be employed as effective additives to reduce the negative impacts of thermal cycles. The mixture of 1.0% nano-SiO2 and 2.5% glass fiber with clay was found as an optimum mixture content, causing elevation of unconfined compressive strength (UCS) from 0.717 MPa to 1.381 MPa even after 12 thermal cycles. The combined impact of nano-SiO2 and glass fiber on the internal friction angle was greater than its effect on the cohesion of the samples. On the other hand, the cohesion and internal friction angle of the samples treated with 1.0% nano-SiO2 and 2.5% glass fiber were obtained 1.36 and 2.47 times of the natural clay, respectively. Microstructural evaluation through SEM images and BET analyses showed that thermal cycles led to an increase in the micro-voids of clay structure and separated clay minerals from each other. Observation of SEM images reflected the fact that thermal stresses due to freeze and thaw periods caused whiskers' growth from nano-SiO2 surfaces. The whiskers and glass fiber lead to modify strength properties and structure of clayey soil by creating filamentary networks on nano and macro scales, respectively.

Comparison of Tensile Properties of Glass Fibre Reinforced Polymer Rebars by Testing According to Various Standards.

The widespread use of glass fibre reinforced polymer (GFRP) bars in reinforced concrete (RC) elements has yet been limited due to the anisotropic and non-homogeneous material behaviour of GFRP. The material characteristics of GFRP bars from different manufacturers vary as a function of several factors. Several standards have developed various procedures to investigate the mechanical characteristics of GFRP bars, but universal methods to test different types and diameters of GFRP bars in tension have not been fully developed. Due to the lack of such a standardized test procedure, there are some doubts and gaps in terms of the behaviour of GFRP bars in tension, which has led to lack of reliable information on their tensile properties. The determination of tensile characteristics of GFRP bars, including the tensile strength, modulus of elasticity, and ultimate strain, according to various test standards, is the main subject of the paper. This paper reports test results for tensile characterization obtained on four types of GFRP bars from four manufacturers with six various diameters. Moreover, the study compares various test procedures according to seven standards to characterize the tensile properties of GFRP bars, to examine the proposed test procedures, and to reveal main differences.

Study of Quasi-Static Compression Behaviour of Hollow Tubes Made of Glass/Epoxy Composite

Composite materials have been used widely in various engineering fields. Composite materials possess low weight, corrosion resistance property, and specific strength, and due to these facts, composite materials are becoming popular among researches and scientists. Now a day, the glass fibers offer the potential to acts as a reinforcing material for composites alternative to the use of glass fiber, carbon fiber and other man-made fibers. In present work hallow tube composites of epoxy – glass fiber was prepared by hand lay-up technique. Mechanical characterizations of prepared hollow tube composites were carried out. Mechanical results were improved; we considered the hollow tubes of glass fiber and epoxy in different proportions such as 50% of glass fiber and 50% of epoxy, 60% of glass fiber and 40% of epoxy, 66% of glass fiber and 34% of epoxy. The maximum compression strength was obtained in the ratio of 50:50 that is 57.69N/mm2, the maximum load at the peak was obtained in the ratio of 60:40, that is 14.61kN and the maximum deformation at the peak was obtained in the ratio of 60:40 that is 8.03mm.

CuO coatings on glass fibers: a hybrid material for CO2 adsorption and photocatalytic reduction to solar fuels

The CO2 capture and its photocatalytic conversion (CCPC) to solar fuels is one promising route to fighting global warming. The CCPC process implies the use of CO2, solar light, and materials to produce solar fuels of low carbon content. The materials must fulfill with the double function of capture and photocatalytic convert of the CO2 into solar fuels. For this purpose, copper oxide (CuO) is an excellent candidate to act as both: adsorbent and photocatalyst. Scaling-up the CCPC process requires the immobilization of CuO on commercially available substrates such as glass fibers, which offers a homogeneous surface exposure, efficient absorption of solar energy, and an easy application in reactors. In this work, the fabrication of CuO coatings on glass fibers by a simple microwave-hydrothermal method to produce solar fuels (CH3OH and HCOH) in CCPC process is proposed. Three glass fibers with different chemical compositions and slit (open area) were selected as supports. The best efficiency for CO2 capture (3080 mgCO2 g−1) was obtained with the CuO coating deposited in a substrate rich in Na2O and CaO. Once the CO2 was adsorbed, the coatings were exposed to visible LED light to carry out its conversion to solar fuels (CH3OH and HCOH). According to the results, both high CuO content and high slits in the fibers promoted an increase in the CO2 conversion to HCOH (2.7 nmol cm−2 h−1) and CH3OH (37.6 nmol h−1 cm−2). The presence of Na2O in the substrates played an essential role as a hole scavenger in the photocatalytic CO2 reduction, preventing the re-oxidation of the products. The use of glass fibers as support of CuO promoted efficiencies up to 11 times higher than other materials used in CCPC process.

Fabrication and analysis of aluminium foam with glass fiber based on PMC for helmet applications

This work concentrates on design, manufacturing and improving the impact strength as well as compression strength of helmet using glass fibres. The work makes use of glass fibre and foams of aluminium for design and experimentation purpose. Materials that absorb high energy is used to make the mould using which the helmet is fabricated. This can result in reduced weight and improved strength of the helmet with minimal wearing property. Hand layup method is used form making the helmets. The cross sectional area collapses and the compression stress of 2.7 KN/mm2. The breaking load of the test specimen was recorded as 8.2 KN and the ultimate tensile strength was 101 N/mm2. The impact strength was recorded as 120 J/mm2.

Influence of the addition of glass fibers reinforcements in the flexural strength of acrylic resin

Objective: To evaluate the influence of glass fiber reinforcements used in nautical and sports products on the flexural strength of acrylic resin. Materials and methods: Thirty thermoactivated acrylic resin bars (25 x 10.5 x 3.3 mm) were used. The samples were shared in 3 groups: bars with no glass fiber (control group, n = 10), bars reinforced with glass fiber and 0.18 mm thickness (group F1, n = 10) and bars reinforced with glass fiber and 0.80 mm thickness (group F2, n = 10). After 48 hours, samples were submitted to compression test in order to evaluate flexural strength. Obtained data were statistically analyzed with significance level of 5 %. Results: It was observed that the use of glass fiber effectively increased the flexural strength compared to the control group; the thickness of the glass fiber, however, did not present statistical differences. Conclusion: The use of fiber glass is a simple and cost-effective alternative to improve acrylic resin performance.KeywordsFlexural strength; Water sports; Dentures.

Mechanical properties of polymer matrix composites: Effect of hybridization

The current work involves the development and mechanical characterization of polymer composites prepared by the use of glass fibers and micronized rubber powder fillers reinforced in epoxy matrices. The composites were prepared by keeping weight fraction of matrix as 50% and varied the wt% of the reinforcements using hand layup technique. The results revealed that, 40 wt% of E-Glass and 10 wt% of micronized rubber powder filler reinforced composites yields better mechanical properties.

Critical Review of use of Glass Fiber Reinforced Gypsum (GFRG) Panels in Housing in India

Critical Review of use of Glass Fiber Reinforced Gypsum (GFRG) Panels in Housing in India - written by Kuldeep Kumar , Devika Nayal published on 2020/03/07 download full article with reference data and citations

Effects of deposition velocity in the presence/absence of E6-glass fibre on extrusion-based 3D printed mortar

Additive Manufacturing (AM) technologies are widely used in various fields of industry and research. Continual research has enabled AM technologies to be considered as a feasible substitute for certain applications in the construction industry, particularly given the advances in the use of glass fibre reinforced mortar. An investigation of the resulting mechanical properties of various mortar mixes extruded using a robotic arm is presented. The nozzle paths were projected via ‘spline’ interpolation to obtain the desired trajectory and deposition velocity in the reference frame of the manipulator. Along each path, various mortar mixes, with and without chopped glass fibre, were deposited at different velocities. Tests were conducted to determine their mechanical performance when incorporated in printed structures with different layers (1, 2, 4 and 6 layers). The results are compared with those of conventional cast-in-place mortar. In this study, the mixes consist of ordinary Portland cement, fine sand, chopped glass fibres (6 mm) and chemical admixtures, which are used to print prismatic- and cubic-shaped specimens. Mechanical strength tests were performed on the printed specimens to evaluate the behaviour of the materials in the presence and absence of glass fibre. Robot end-effector velocity tests were performed to examine the printability and extrudability of the mortar mixes. Finally, horizontal and vertical line printing tests were used to determine the workability, buildability and uniformity of the mortar mix and to monitor the fibre flow directions in the printed specimens. The results show that printed specimens with glass fibre have enhanced compressive strength compared with specimens without glass fibre.

Natural fiber reinforced high calcium fly ash geopolymer mortar

This study investigated the properties of high calcium fly ash geopolymer mortars containing natural fibers. Two types of natural fibers, namely sisal fiber and coconut fiber were incorporated in the geopolymer mortar with varying proportions at 0%, 0.5%, 0.75%, and 1.0% volume fraction. The mechanical, thermal, and physical properties of geopolymer mortar reinforced with fibers were tested and compared with those of glass fiber (synthetic fiber) and control (0% fiber) geopolymer mortars. Results revealed that the addition of natural fiber (sisal and coconut fibers) as reinforcing materials resulted in significant improvement in tensile and flexural strength performances similar to the use of glass fiber. Meanwhile, the workability, dry density, ultrasonic pulse velocity, and compressive strength values tended to decrease.

Mechanical properties of composite materials based on waste plastic – A review

Over the years there has been a growing interest among researchers to produce and evaluate mechanical properties of fiber reinforced recycled thermoplastic and thermoset resin composites which are derived from non-biodegradable and non-renewable plastics that comprise of massive fraction of disregarded solid waste today. Current paper reviewed all such developments with special emphasis to recycled thermoplastic matrix composite materials. In section of composite materials based on recycled thermoplastic matrix, focus was laid on effect of fiber type and its content comprising of use of glass fibers that are artificial reinforcements and bast fibers, wood fibers, date palm leaf fibers, bamboo fibers that are natural fiber reinforcements. Furthermore, for the same regime, the effect of blending, effect of compatibilizer, effect of fillers, effect of processing method, effects of fiber surface treatment, effect of processing parameters and effect of processing condition was briefed on overall mechanical performance of recycled thermoplastic matrix composites. While, few studies that exist in the archival literature in section of composite materials based on thermoset resin matrix are described in chronological order. Based on the critical review, it is revealed that no significant experimental work is available on fatigue and creep properties of artificial and natural fiber reinforced recycled thermoplastic and thermoset composites. In this regard, studies so far reported has only investigated detailed mechanical properties such as tensile strength, impact strength, adhesion strength, flexural properties, etc.

High performance glass fiber reinforced concrete

The research article outlines the experiment for the fresh properties of concrete and harden concrete which is conducts to find the use of glass fibers with structural component like cube cylinder and beam. To find the strength and durability of M20 grade of concrete with Glass Fiber Reinforced Concrete (GFRC). GFRC is mixed with concrete in three different variation and identify the fresh properties of the concrete and the harden strength of the concrete. GFRC varies from 0 to 1 percentage by mass of concrete and the properties of this FRC like compressive strength, toughness, modulus of elasticity and flexure strength were studied.

Assessment of GFRP bond behaviour for the design of sustainable reinforced seawater concrete structures

Freshwater is an increasingly scarce resource. Its use in the production of concrete is one important contributor to its fast depletion. Alternatively, the use of seawater for reinforced concrete production, combined with the use of glass fibre reinforced polymers (GFRP) as reinforcement, may represent an interesting solution to increase concrete sustainability. The objective of this paper is to explore this promising solution through the development of concrete compositions with seawater. Additionally, it is also an objective to assess the bond behaviour between GFRP rods and concrete, in a design perspective. The influence of concrete age, rod diameter and anchorage length were also investigated. An analytical model capable of determining the local bond stress-slip laws was used. Results demonstrated that the use of seawater had no relevant effects on neither concrete mechanical properties nor bond behaviour.

Undrained performance of sustainable compacted sand-bentonite–glass fiber composite for landfill application

Abstract A compacted sand-bentonite composite is considered as a barrier material for the use at the landfill. If the strength of the barrier material is not adequate, then the actual operation of the liner system can be endangered. Worldwide environmental awareness and high dumping cost have influenced the possible use of glass fibers for landfill application. Since the composite possessed a lower shear strength, glass fiber can be added to enhance its shear strength. The purpose of the present investigation was to assess the effective shear strength parameters of compacted sand–bentonite mixture, mixed in a proportion of 80:20 and reinforced with glass fiber. Glass fiber with an aspect ratio of 40, 80, and 120 were added to sand-bentonite composite in a fraction of 0.5, 1, and 1.5%. Test result suggested that the negative excess pore water pressure increased for the composite with an aspect ratio of 40; however, it decreased gradually with an increase in the aspect ratio to 80 and 120 for any fiber concentration. At a fiber content of 1.5% with the aspect ratio of 80 and 120, the peak effective frictional angle was almost constant. The cohesion component enhanced moderately up to the aspect ratio of 80 for any fiber concentration and remained constant with a further increase in the aspect ratio from 80 to 120. Residual strength parameter of the composite improved significantly with the addition of glass fiber. Initial tangent increased up to 1% fiber content for any aspect ratio, and then reduced with the further addition of glass fiber. The effective principal stress at failure predicted using a mathematical model showed an excellent agreement between predicted and experimental values.

Compression Splices of GFRP Bars in Unconfined and Confined Concrete Columns

AbstractAlthough the use of glass fiber–reinforced polymer (GFRP) bars as compression reinforcement in RC columns has been extensively investigated, no research has been conducted on spliced GFRP b...

Effects of corona discharge treatment on surface and mechanical properties of Aloe Vera fibers

Green Composites comprising of lignocellulosic fibers are low cost sustainable materials. They are environmentally friendly alternative to the use of glass fibers as reinforcement in engineering composites. In order to improve the interfacial interaction with the matrix, lignocellulosic fibers are subjected to fiber surface modification. The aim of this work is to study the influence of corona discharge treatment on morphology and mechanical properties of neutral fibers. In this respect, Aloe Vera fibers were treated with corona discharge during 5, 10, and 15 min. Scanning electron microscopy (SEM) micrograph had shown the rough surface morphology and degradation of fibers due to etching mechanism causes by corona. Furthermore, mechanical testing on treated fibers showed a decrease of elastic modulus and ultimate tensile strength. The influence of corona treatment on fibers was also studied by Fourier transform infrared-spectroscopy (FT-IR) and X-ray diffraction (XRD).