Papers by Keyword: Fiber

Abstract: An information model of an ancient building in Odessa was built during its restoration with the calculation and strengthening of load-bearing structures. The Autodesk Revit complex was used to build the model. Visualization was performed in the Lumion program. The load-bearing capacity of reinforced concrete structures – lintels and floor slabs – was checked. A technical examination showed that the floor slabs had no damage and did not need reinforcement, so a model of the slab was built in ANSYS 21R2 and an analysis of its load-bearing capacity and deformability was performed using the finite element method, which showed that the stresses and deflections of the slab under operating loads are significantly less than the maximum values. And upon visual inspection of the jumpers, it turned out that some of them were damaged in the stretched area and needed reinforcement. This reinforcement was carried out with steel fiber reinforced concrete, having previously carried out laboratory experimental studies and computer modeling in Autodesk Robot Structural Analysis Professional.

Abstract: The dyeing ability of the polypropylene (PP) fiber was modified by blending with poly(lactic acid) (PLA). The PP, PLA, and PP/PLA fiber were obtained using the melt-spinning technique in the presence of the polypropylene-graft-maleic anhydride as a coupling. The dyeing ability, mechanical and thermal properties, and crystalline structure of the PP, PLA, and PP/PLA fibers were investigated. The effect of dyeing ability was measured using the CIE L^* a^* b^*. The a* value of the PP of 11.91 increased to 43.48 for PP/PLA90, showing a light pink to red color. The SEM images demonstrated smooth fiber with color coating on the fiber. The mechanical property of the fiber indicates that increasing the PLA decreased the tenacity of the PP fiber. The melting behavior of fiber increased with the PLA. The XRD presented the PP's crystalline and the PLA's amorphous structures.

Abstract: Perovskite semiconductor have gained increasing attention in the recent years. However, pristine halide perovskites often faces bottle-neck related to low their stability. Herein, for the first time synthesis and fabrication of CsPbBr3/PAN fiber composite with electrospinning method is reported. CsPbBr3 quantum dots (QDs) embedded PAN fiber were successfully fabricated based on the XRD and FTIR test result. The result demonstrates electrospun fiber stable for over than one week in the condition of being immersed in water. The CsPbBr3 QDs was synthesized by Ligand Assisted Reprecipitation Process (LARP) method. The average particle size of our CsPbBr3 particle sizes ranging from 80 to 240 nm. Our findings reveal that the effect of variations between toluene and acetone had an effect on the size of the fiber and the intensity of photoluminescence reduction of the CsPbBr3/PAN fiber composite. Which is the smallest fiber and the lowest reduction intensity belongs to the 4:1 variation, namely with a fiber size of a 727.56 nm and a percentage decrease in intensity of 66,67%.

Abstract: The subject of the study presented in this paper is to quantify the effect of fiber content on the mechanical and mainly fatigue response of fine-grained cement-based composites. The reference cement-based composite was without fibers. Three types of fibers were used as dispersed reinforcement: tire cords (waste material), steel, and polypropylene. For each type of fiber, mixtures with varying reinforcement levels per volume were prepared: 0.0 % (reference composite), 0.5 %, 1.0 %, and 1.5 %. Prismatic specimens 40 mm × 40 mm × 160 mm were prepared and tested. A total of 10 composite variants were investigated. The ages of the specimens for the static three-point bending tests were 28 days, for the compression tests were 28, 120, and 275 days. While for the fatigue tests, it was approximately between 110 and 180 days. The obtained compressive strength values for the above-mentioned composite ages were approximated by a selected exponential function and the results of the fatigue tests were standardized to a nominal age of 28 days using them. All used types of reinforcement increase the strength values of the composites even from the lowest fiber doses. A positive effect of fiber dosage above 0.5 % on the fatigue behavior of composites was shown only in the case of reinforcement with commercial steel fibers.

Abstract: The conducted research program was focused on the creation steel fiber reinforced concrete (SFRC) dedicated for casting columns with fractal based cross-sections. The columns in question were planned to be cast using 3D printed plastic formworks. Harnessing 3D printing of plastic enables easy creation of cross-sections which are not possible to be achieved using traditional formwork techniques. The mix had to be characterized by consistency enabling almost self-compacting behavior, reasonably high volume of fiber (volumes of fiber ranging from 0.5% to 2.0% were considered) and the maximum diameter of used aggregate of 2mm. Due to very complicated cross-sections of planned columns the mix had to be able to effortlessly penetrate very elaborate shapes of fractal formwork. All desired properties were achieved during the research program using two admixtures and micro steel fiber. The mix was tested using column specimens with circular, square and pentagon cross-sections.

Abstract: The rapid development of the timber industry has caused the total capacity of the Indonesian timber industry to exceed the ability of production forests to provide raw materials sustainably. One of the industries that require a supply of wood as its main raw material is the furniture industry. The raw materials for furniture that are commonly used are logs and planks. In recent years, there has been the development of new materials that use natural fibers as polymer reinforcement, which can be used to replace wood materials. The material is a natural fiber composite. Composite materials reinforced with natural fibers are widely used in aerospace, automotive, circuit boards and other applications. One of the natural fibers that can be used as a composite is straw fiber. This high proportion of cellulose in straw fiber can be used for several things, one of which is composite materials. The utilization of rice straw fiber and epoxy as raw materials for making composites is an alternative to overcoming the increasing demand for wood. The purpose of this study was to determine and analyze the effect of volume fraction and alkalization treatment on the physical and mechanical characteristics of straw fiber composites, also to determine and analyze the effect of adding a coating of PE/SiO₂ on the hydrophobic characteristics of straw fiber composites. The physical and mechanical properties of the composites were evaluated based on the SNI 03-2059-2006 and SNI-01-4449-2006 standard. The volume fractions used are 40%, 50%, and 60%. The length of the fiber used is 5 mm. And the alkalization variables used were 5% and 10% NaOH with 4 and 8 hours of immersion. The compressive strength decreased by adding fiber volume fraction and increased by higher treatment alkalization. The coating method can produce composite with the contact angle value of more than 90^o.

Abstract: Reduced graphene Oxide (RGO) was synthesized from treated Borassus Flabelifer L. The Isotherms adsorption kinetics of methylene blue on RGO was studied in this research. Borassus Flabelifer L as the raw material was heated at 650°C, 750°C, 850°C for 2 hours with the flowing of nitrogen gas. X-Ray Diffraction (XRD) used to clarify the RGO phase. The surface morphology was characterized by Scanning Electron Microscopy (SEM), meanwhile the absorbance of methylene blue on RGO studied by UV-Vis Spectrophotometry. The surface area of ​​RGO with 70.31 m²/gr; 110.90 m²/gr and 25.52 m²/gr when heated at 650°C, 750°C, and 850°C, respectively. The RGO phase was obtained through the XRD measurement at all activation temperatures. SEM and surface area measurement proved that the activation temperature of 750°C, was the optimum temperature where the RGO has more pores and a larger surface area. Based on the study of adsorption kinetics, the highest adsorption efficiency was obtained at 850°C.

Abstract: Every year, the Philippines experiences hot and rainy weather. For those who choose to remain at home, summer feels like torture. So, Filipinos have no choice but to turn on their air-conditioning system, which can cause their electricity bill to skyrocket. Corn husk fibers, being a waste product, have great potential to be applied in home textiles, home furnishing, carpet, rugs, and packaging of food grains and crops. The researchers thought of making thermal insulation ceiling panels made of corn husk fibers. The study yielded a result of 0.119 W/m.K for thermal conductivity using a calibrated hot box, below the 0.25 W/m.K maximum threshold for thermal conductivity value. Furthermore, its fire resistance characteristic made it less susceptible to small fire attacks. It was also found that the insulator has 2.19% and 8.42% water absorption values for short and long-term soaking, which is less than the 40% range value for water absorption. Hence, it can be said that it is an excellent thermal insulator.

Abstract: The study involves the use of high density polyethylene (HDPE) as a filament for 3D printing. Considering the warpage and adhesion problem of HDPE on the build plate during 3D printing, this was addressed through the incorporation of wood flour compatibilized with styrene-ethylene-butylene-styrene grafted maleic anhydride (SEBS-gMAH). The composite wood-HDPE (cHDPE) was studied to observe warpage changes. Using different SEBS, heat bed parameters and identification of the suitable print heat beds for HDPE was conducted. Results from the mechanical testing show that the compressive strength and elastic force of virgin HDPE (vHDPE) increases with infill percentage, while the same properties for cHDPE increases up to 50% infill density/percentage then decreases as it approaches 100% infill percentage. Digital microscopy imaging shows that poor layer adhesion initiated the poor compressive performance of cHDPE. Warp studies reveal that wood flour significantly decreases warping of HDPE by 42.88% at 50% infill density. While different SEBS brands show similar effectiveness as heat beds in reducing warping of HDPE during printing.

Abstract: This research investigates the behavior of different reinforcement materials on the mechanical and ballistic properties of a hybrid composite, where two types of reinforcement in different combinations based on the Taguchi technique. Two different methods can be used to analyze different properties, bigger is better when it comes to the impact strength and hardness of the composite making the specimen that containing the highest value of impact strength belonged to (22.5% Kevlar, 30% E-glass, 1% Silicon carbide and 2% Titanium carbide)combination, while the highest value of Hardness came from (30% Kevlar, 15% E-glass, 1% Silicon carbide and 1% Titanium carbide). While smaller is better when we refer to the ballistic penetration depth under high speed impact, and the smallest depth of the backface signature came from (15% Kevlar, 15% E-glass, 2% Silicon carbide and 2% Titanium carbide) combination.