Papers by Keyword: Glass Fiber

Abstract: Studying the effects of hybrid reinforcement made of nano-zirconium oxide and chopped glass fibers for poly methyl methacrylate (PMMA) denture bases, nano- ZrO₂ (n ZrO₂) at grain sizes (46.7 nm) which measured using Atomic Force Microscopy (AFM) and different ratios on the mechanical characteristics was the aim of this study .To make the pure sample, a 2:1 powder to liquid ratio of typical acrylic resin was used. Hybrid composites with varying concentrations of nano-ZrO2 (nZrO₂) and glass fiber (GFs) (2.5%nZrO₂+2.5% GFs), (3.5%nZrO₂+1.5%GFs), (1.5%nZrO2+3.5% GFs) were introduced. Mechanical tests as tensile strength, flexural strength, impact strength, shore D hardness are used to learn about the properties of manufactured composites. Antibacterial testing, water absorption, density testing, and thermal conductivity these indicated that composites may be effectively turned into filler material. In addition to X-ray diffraction (XRD), Scanning Electron Microscopy (SEM). The result show increased the mechanical properties of the PMMA denture base material. The tensile strength flexural strength, and impact strength increase for all hybrid ratio and reach maximum value at the concentration (2.5%nZrO₂+2.5% GFs) compared to unreinforced PMMA.While hardness increase and reach maximum value at the concentration (3.5%nZrO₂+1.5% GFs). In addition, thermal conductivity and density, the maximum value at concentration (1.5%nZrO₂+3.5% GFs), as well as water absorption decrease as ratio of nZrO2 increase this shoed in concentration (3.5wt. % nZrO₂ +1.5wt. %, GFs).

Abstract: . This paper evaluates the thermal performance of non-autoclaved aerated concrete (NAAC) produced with crushed waste glass bottle aggregate and glass fiber. A total of six different mixtures, including the partial substitutions of normal sand with waste glass sand (WGS) (0%, 15%, and 30%) and glass fiber (1%, 2%, and 3%), were designed. After the compressive strength and thermal conductivity (λ) of each NAAC mixture were firstly determined, the potential of NAAC to improve the thermal performance of student residential buildings was assessed. The energy-saving effect of NAAC was simulated using Autodesk Revit software tools in two different cities, Nur-Sultan in Kazakhstan and Boston in the USA. Moreover, annual heat loss was calculated. Test results present that the increase of WGS and glass fiber contents leads to increasing compressive. Interestingly, while increasing WGS content in the mixture decreases λ, increasing fiber content increases λ despite a slight variation. The lowest annual heat loss was obtained from the mixture containing 70% normal river sand, 30% WGS, and no glass fiber. 70NS-30WG-0GF. Finally, the energy performance simulation result indicates that NAAC used in a residential building leads to significant energy savings compared to normal concrete and brick structure.

Abstract: In automotive applications, replacing heavy and expensive materials with light and cheap natural fiber leads to noise reduction, strength enhancement and fuel management. Enhancing the absorption of energy, controlling the failure style of composite thin shell tube and utilizing it instead of thin-walled steel columns in vehicle structural parts can provide more protection for occupants during collisions. This research investigates the possibility of gradually replacing metallic materials with natural and hybrid fibers in industries. The hand layup technique is utilized to study the performance of fiber reinforced epoxy composite tubes under static crushing to examine the jute fiber effect with different fibers types on the failure mechanism. The research studies the effect of using different fibers types on stress and strain after determining the tubes load-displacement curves. Total of 48 specimens are fabricated at room temperature and tested with a constant speed 1.5 mm/sec using one resin (epoxy) type and three fibers types (Glass, Kevlar, Jute). Two circular and square geometries with three heights (200 mm,250 mm,300 mm) including two circular diameters and two square side lengths are used to investigate the crashworthiness parameters. The Kevlar and glass fiber tubes showed low and unstable behavior. Replacing two layers of Kevlar or Glass fiber by two layers of natural jute fiber enhanced the crash worthiness parameters particularly, failure type. The hybrid jute with Kevlar accomplished desirable and best results followed by hybrid jute with glass.

Abstract: The current study ensures the possibility of improving the mechanical and dielectric properties of polystyrene/kaolin reinforced with glass fibers. Polystyrene was dissolved using coloring in a ratio of 1 to 2. The prepared composites were studied and the results of the tensile, impact, hardness, thermal conductivity, and dielectric, has been obtained. Through the tensile results, it was found that with an increase in the addition of kaolin, both the yield points and the Young modulus decreased with a small and noticeable increase for the sample with the percentage of addition beyond 8 percent in Elongation, and shown high flexibility. The highest tensile strength appeared in the pure sample (x= 0%), where the value reached 22.85 MPa, while the lowest was for the sample with ratio 2%. While the impact result showed a noticeable increase with the increase in the percentage of addition of kaolin in the few percentages only. The sample with an addition rate of 8% kaolin, showed a high rebound energy, through the results of the energy absorption test, and it had the highest thermal conductivity and dielectric coefficient.

Abstract: Fabric Reinforced Cementitious Matrix (FRCM) and Composite Reinforced Mortar (CRM) are used in structural strengthening of heritage masonry construction due to their high compatibility with the substrate. Due to the interaction between the reinforcement fibers, made by glass or basalt, and the alkaline matrix, durability problems may be met in the field. In this study a large experimental program is presented and discussed in a synthetic form, with reference to glass fibers reinforcements used in FRCM and CRM systems. Ageing conditions were reproduced in a laboratory environment by immersing the glass-fibre reinforcements into three different solutions. The artificial alkaline solutions used in this study simulated the chemical aggression of lime mortar matrix, Portland cement matrix and standard alkaline solutions (ASTM standard). Four conditioning periods were applied as ageing protocol: 500hrs, 1000hrs, 2000hrs and 3000hrs. Accelerating effects were produced by increasing the temperature during ageing, from 23°C to 40°C and 70°C. The residual mechanical properties and physical damage observed by using Scanning Electronic Microscopy (SEM) are discussed in the paper. The decay of the mechanical properties is highlighted in terms of tensile strength on the whole FRCM strengthening system and for each of the constituents.

Abstract: Adobe masonry (AM) dwellings are a considerable portion of existing buildings stock worldwide, particularly in developing countries. Several earthquakes occurred during last decades dramatically showed a high seismic vulnerability of such constructions, which are not generally engineered. Therefore, several research groups have been involved in the investigation about effective and viable retrofitting solutions for AM buildings. Currently, most of studies available in literature addressed the issue by means of experimental programs consisting of dynamic or static tests on reduced- or full-scale specimens, representing partial or complete AM dwellings. Nevertheless, in those works, limited or no attention was generally paid to the crucial issue of the spatial variability of material properties within AM, which can produce critical forms of mechanical response and premature failure. In this study, three series of seven AM wallets were tested under monotonic diagonal compression load: one series consisted of unreinforced specimens (used as benchmark) and the remaining series were strengthened with two textile reinforced matrix (TRM) systems, made of either hemp or glass meshes. Masonry joints and matrix were produced using the same mud mortar, which is a typical mortar of existing Italian AM buildings. Experimental outcomes of tests in terms of observed damage and response curves are presented, along with a comprehensive characterization of mortar and bricks. Then, with the aim to draw out general and robust trends about TRM effectiveness as strengthening solution in the improvement of shear strength and ductility capacity, the response variability was quantitatively investigated via statistical analysis of recorded stress–strain samples.

Abstract: The use of fabric-reinforced cementitious matrix (FRCM) composites for strengthening and retrofitting of existing masonry structures is nowadays a well-established practice, due to the speed and ease of application, low invasiveness, and high performance-to-cost ratio. Among different FRCMs, those comprising glass fiber textiles (GFRCM) represent an excellent choice due to the good mechanical properties and low cost of the raw material. However, limited information is available on the effect of environmental conditions on the performance of GFRCM composites and on their long-term behavior. This paper investigates the effect of different environmental conditions on the tensile performance of a GFRCM composite comprised of a cement-based matrix reinforced with an open-mesh alkali-resistant glass textile. Namely, the effect of hygrothermal conditioning, saline environment, alkali environment, freeze-thaw cycles, and dry heat conditioning were considered. After conditioning, specimens were tested using a clamping-grip tensile test configuration and the effect of the various exposure was analyzed comparing the composite tensile strength, ultimate strain, and elastic modulus of conditioned and control specimens. The experimental results show a good performance of the tested GFRCM composite with respect to the conditions considered.

Abstract: This paper presents the effect of accelerated salt spray (fog) exposure on commercially glass fiber reinforced polyester composite to determine the durability of the material. Aging behavior after exposure in the salt-spray environment was studied by mechanical properties i.e. flexural stress and flexural modulus. The accelerated salt spray exposure was conducted by Copper-Accelerated Acetic Acid Salt Spray (CASS) Test according to ASTM B368. The CASS exposure was carried out for 120 hours and observed every 24 hours. The flexural modulus results tend to be constant up to 4 days and more significant change on 5^th day of measurement. Furthermore, the morphology of specimens investigated by a Scanning Electron Microscopy (SEM). The SEM results also showed that only scratch occurred on the surface of the specimens test. The longer of the CASS exposure time, the higher the number of scratches. From this study, it could be concluded that Glass Fiber Reinforced Polyester Composite has slightly damage for 120 hours CASS test exposure.

Abstract: This paper investigates the combined effect of waste soda-lime glass sand and glass fiber on the physical and mechanical properties of none-autoclaved aerated concrete (NAAC). The use of both soda-lime glass sand and glass fiber can provide silica-rich materials in the aerated concrete and can enable the elimination of an autoclaved curing by enhancing the physical and mechanical properties in aerated concrete. In this study, a total of six mixture proportions were designed to evaluate these properties in NAAC. The mixture parameters included the partial substitutions of normal sand with soda-lime glass sand (0%, 15%, and 30%) and glass fiber (1%, 2%, and 3%). A series of tests were conducted to determine density, absorption, porosity, and both compressive and flexural strengths of the NAAC. Test results present that the increase of glass sand content leads to the increasing of both compressive and flexural strengths. Moreover, the combination of the use of glass sand with glass fiber also increases the strength up to 2 times (the mixture of 30% glass sand and 3% glass fiber). Furthermore, test results indicate the relatively good relationship between the density, porosity, and of NAAC with good accuracy.

Abstract: Due to the elevating demand to replace the conventional cement concrete with any other building material, there has been a continuous effort to promote the properties of geopolymer concrete. The objective of this paper is to reduce the brittleness of geopolymer concrete. This research paper goes for exploring the impact of high and low young’s modulus fiber in geopolymer concrete made of M-sand. Mix proportion of various materials is based on the Rangan’s proposed Mix design. Geopolymer concrete used in this investigation is the Fly ash – Ground Granulated Blast Furnace Slag blend based. Concoction of NaOH solution and Na2SiO3 solution is used as the alkali solution. Sine 80 percent of the source material is flyash, the specimens are exposed to heat curing. Fresh property and hardened characteristics like workability, ductility factor, compressive, split tensile, flexural and impact strength are assessed in this study. Significant increase in the engineering properties is observed with respect to both the fibers. This work unveils lot of potential in the vicinity of Geopolymer concrete.