Fiber Weight Ratio Research Articles

Experimental Investigation of Mechanical Behavior of CFRP-AA7075-T6 Composite and Finite Element Analysis for Automotive Wheel Rim Application

Lightweight with high strength material is the new requirement of the modern world and composite materials are the best option as the solution. Owing to high strength to weight ratio and corrosion resistant of Carbon Fiber Reinforced Polymer (CFRP) compared to aluminum (AA7075-T6), they are well suited to fulfill the demand of modern needs. The present work investigates the mechanical behavior of CFRP-AA7075-T6 composite material experimentally. Finite element analysis (FEA) has also been conducted for the evaluation of stress, strain, and deformation for the application as automobile wheel rims. CFRP-AA7075-T6 shows superior to AA7075-T6 in terms of flexural strength. Impact test reveal that the prepared composite absorbed 11% more energy than AA7075-T6. The strength-to-weight ratio of the prepared composite is 73% higher than that of AA7075-T6. FEA of automobile wheel rim models of prepared composite gives better results than the AA7075-T6 sample. CFRP-AA7075-T6 composite exhibits the lower deformation and equivalent elastic strain of 18.11% and 17.26% respectively than AA7075-T6 at same load level.

Sustainable composite materials with date palm rachis fibers for enhanced insulation and structural integrity

This investigation focuses on the development and characterization of sustainable composite materials for insulation and structural components in the automotive and shipbuilding industries, by incorporating date palm Rachis fibers into an epoxy matrix. Thus, we evaluated the effect of the weight ratio (ranging from 0 to 15 wt%) of Rachis fibers (0.315 mm) on the mechanical, physical, surface morphology, thermal properties, and water absorption. It turns out according to the study that, the XRD pattern revealed the amorphous nature of the composite. This new material can be used as composite material itself or as a skin of a sandwich composite material. The Epoxy-Rachis (ER) composite materials exhibited a low thermal conductivity of 0.21 W/ (m.K) and a low thermal diffusivity of 0.17 mm2 s−1 presenting high thermal insulation and construction properties. The SEM images showed that increasing Rachis fiber concentration produces a heterogeneous bio-composite material. The resulting composition showcases ductile fracture behavior with a flexural modulus (Ef) of 3.21 GPa and a bending strength (σ) of 9.28 MPa. These attributes underline the suitability of this composite for applications requiring efficient thermal insulation and robust construction properties, while simultaneously contributing to environmental sustainability and environmental benefits.

Effect of alkali treatment on mechanical and water absorption properties of biodegradable wheat-straw/glass fiber reinforced epoxy hybrid composites: A sustainable alternative for conventional materials

Fiber-reinforced polymer composites are preferred over conventional materials because of their superior strength and modulus. Previously limited due to high manufacturing costs, synthetic fibers have been replaced by some natural fibers, such as waste wheat straw fibers. Here, epoxy-based polymer composites' mechanical and physical properties have been investigated, focusing on fiber weight ratios for both treated and untreated fiber. The research found that treated fibers display more effective mechanical qualities than untreated fibers, with a higher tensile strength of 54.4 MPa. The untreated Wheat Straw-Glass fiber reinforced composite has a less tensile strength of 26.3 MPa (10 wt% fiber). Pure resin-based composite has the most minor tensile strength at 1.52 MPa. The highest flexural strength obtained for hybrid composite is 88.76 MPa for treated fiber with epoxy resin and 49.6 MPa for untreated 30 wt % fiber. At the same time, the sole epoxy resin composite has the lowest value of 10.60 MPa. Untreated fiber (30 wt%) has the highest impact energy of 8J. Untreated wheat straw fiber absorbs more water due to its hydrophilic nature. In contrast, treated fiber exhibits better bonding and minimal water content, and the sole epoxy resin composite exhibits hydrophobic properties, resulting in less water absorption. The treated fiber displays better bonding than the untreated fiber throughout the SEM analysis. Wheat Straw fiber is mainly used for biodegradable plastic formation, housing construction, building materials, etc.

Development and mechanical characterization of horse hair with titanium dioxide nanoparticles reinforced polyester composite

This study aims to examine the effects of waste material more especially horse hair as fiber on mechanical and physical properties. Tensile, flexural, impact, and hardness properties of horse hair fiber and titanium dioxide nanoparticles (TiO2 NPs) polyester composite were investigated to determine whether the latter might be used as a new material in various engineering applications for a longer life. To improve the impact resistance of the composite, horse hair fiber is mixed in different ratios with titanium dioxide and polyester as filler. Tensile, flexural, and impact mechanical properties were assessed using the Universal Testing Machine, the Rockwell Hardness Testing Machine, and the Izod Impact Test. Specimens were hand-put up using various fiber weight ratios. The results of this study showed that Specimen 5 showed a tremendous increase in flexural strength (98.87 MPa), tensile strength (91.46 MPa), hardness (115 HV), impact strength (15.98 J m−1), and water uptake (10.18%) as compared to the neat and also with the other Specimens. Scanning electron microscopy (SEM) was used to investigate the fracture surface in more detail in order to search for failure mechanisms and the dispersion of nanoparticles. SEM micrographs verified the uniform dispersion of the nanoparticles. Results suggest that these composites can be used as a material for a variety of applications, including biological claims that they are a practical, durable, and environmentally friendly choice.

Investigating the creep resistance of E-glass/polyester composite for automotive structural components

This study was focused on investigating the influence of fiber-to-matrix weight ratios on the creep behavior of a composite material made from E-glass fiber and polyester resin. The aim was to assess the practical applicability of the composites for aircraft and vehicle structural parts by checking creep strength. The test specimens were prepared using the hand layup method, combining E-glass fiber and polyester resin. Three different fiber-to-matrix weight ratios (65/35, 55/45, and 35/65) were selected and the test specimens were manufactured according to the ASTM D2990 standard. The tests were conducted on each weight ratio using creep loads of 20, 30, and 40 N., and finite element analysis (FEA) was performed to substantiate the experimental results. Based on the experimental and simulation results, it was observed that the composite with a fiber weight ratio of 65/35 has 62.43 Mpa stress and 7.59 mm deformation. This exhibited favorable creep behavior and higher deformation resistance compared to the other compositions. The finite element analysis results were in good agreement with the experimental findings. This suggests that this weight composition could be preferred for vehicle structural parts. The agreement between the experimental and finite element analysis results further validates the practical applicability of the composite material.

Experimental characterization of Grewia Ferruginea fiber reinforced polyester matrix composite materials

Researchers have recently altered their focus and have become more interested in natural fiber-reinforced polymer composites because they are more ecologically friendly and environmentally conscious than synthetic fiber-reinforced polymer composites. Among the best sources of natural fiber, Grewia ferruginea, sometimes known locally as Lenquata, is a source of natural fiber from other plant fibers. The goal of this study was to create polyester matrix composites reinforced with short Grewia ferruginea plant fibers measuring 10, 20, and 30 mm. The fibers were extracted using the traditional water-retting method and chemically treated with 5% NaOH. The findings indicated that the average tensile strength of a single fiber from Grewia ferruginea plants is 214 MPa, with a density of 1.11 g/cm3. Furthermore, the composite, which was created with a fiber length of 10 mm, fiber weight ratio of 25 %, and polyester matrix composite of 75 %, exhibited superior performance since it is stronger than any combination that was used to create the composite in this investigation, with 18.3 MPa tensile and 35.2 MPa flexural strength.

Experimental and Numerical Studies on the Vibration of Hybrid Composite with an Edge Crack

The hybrid composite plate is increasingly used in marine, robotic arm, and other applications. Edge crack is the greatest common fault in the structural systems during its working time. In this research, the successful fabrications of a hybrid composite of epoxy-based composites reinforced with bamboo and glass fibers have been done to examine the vibration characteristics under free vibration. First-order shear deformation theory is used to study the fundamental natural frequencies of asymmetrically hybrid composite beam with edge cracks for cantilever beam boundary conditions. Both numerical (FEM) using ABAQUS software and experimental investigations are done for the vibration analysis of unidirectional bamboo/glass fiber epoxy hybrid composite (BGHC) beam with edge cracks using fracture mechanics theory. It is observed that implications edge crack with different crack depth and various fiber weight ratio parameters have a major effect on vibration analysis. Also, it is clear that the natural frequencies of the hybrid composite are significantly affected due to the fiber weight ratio and crack depth of the hybrid composite materials. So, crack lengths are playing a vital role in the dynamic or vibration characteristics of the hybrid composite materials. The results of natural frequencies have been shown that they are decreased with an increase in crack depth and an increase in the bamboo fiber weight. Thus, BGHC-2 made from 30% bamboo and 10% glass fiber can be a viable candidate for applications that will produce good vibration properties. Generally, the first-third natural frequency of the hybrid composite beam decreases within the increase of bamboo fiber and decreases in glass fiber. The composite materials having 60% of epoxy with 20% bamboo and 20% glass fiber, and 60% of epoxy with 10% glass and 30% bamboo fibers, are observed with a gradual decrease in the values of natural frequencies with respect to increasing in crack depth. A fine agreement was accomplished between the simulation and experimental results. Therefore, the present approach can be used to identify cracks for mechanical health monitoring by linking the variation in natural frequencies of the hybrid composite beams.

Potential of mango shell powder as a bio filler in flax-jute hybrid epoxy composites: mechanical and wear characterization

Abstract The exploration of natural fillers has garnered considerable attention in response to persistent concerns about material pollution and diminishing resources. In the context of this study, one such natural filler under scrutiny is mango shell powder (MSP), a byproduct derived from mango processing. The central objective of this investigation is to assess the potential of MSP as a filler in flax-jute hybrid epoxy composites, with a keen focus on enhancing their properties. Specifically, the study aims to elucidate the impact of incorporating MSP filler on the mechanical and wear characteristics of these composites. The experimental approach involved the preparation of composite samples with varying weight percentages of MSP filler, ranging from 1 % to 9 % (1 %, 3 %, 5 %, 7 %, and 9 %), while maintaining a constant fiber and matrix weight ratio. The results obtained from the experiments revealed that composite samples containing a 7 % filler exhibited superior mechanical properties, while wear resistance demonstrated a noticeable decrease with the progressive increase in filler content. These findings suggest the potential efficacy of MSP as a filler in enhancing both the mechanical and wear characteristics of flax-jute hybrid epoxy composites, providing valuable insights for further applications in sustainable composite materials.

An examining the static and dynamic mechanical characteristics of milled ramie root reinforced polyester composites

This research works discuss about the effective utilization of waste Ramie Root, that has been in reinforced polyester composites, powdered fillers that have not been treated are used. Four different composites plate were formed with compression moulding technique process consisting of 20, 30 and 40% of Powdered Ramie Root with 80, 70 and 60% unsaturated polyester resin, respectively. The maximum mechanical properties were observed for the composite with 30:70 weight volume percentages of milled ramie root synthetic reinforced polyester. The findings show that the glass transition temperature, storage modulus, and loss factors all rise when the composition of composites changes. Additionally, the powder cohesion force (bonding strength) has a greater impact on dynamic mechanical properties. Thermo-gravimetric the inclusion of Ramie Root powder caused the thermal deterioration peak of the composite to move from 370 °C to 418 °C, according to analysis (TGA) conducted under flowing oxygen. According to the measurement of water absorption, the ideal weight ratio of Fiber: Unsaturated Polyester Resin is 30:70, which modifies the fibres’ surfaces and ensures optimal adhesion between the fibre and matrix in composite materials. Scanning electron microscopic investigation is done to ascertain the fracture behaviour of the composite. As a result of their stability, high tensile strength, and bending stiffness, the produced composites can be used in light-load applications by material technologists.

Investigation on process window of 3D printed continuous glass fiber‐reinforced thermosetting composites

Abstract3D‐printed continuous fiber composites offer high strength in desired directions, which has attracted researchers' attention. In general, thermoset composites provide better results than their thermoplastics counterparts due to their higher modulus, low viscosity resin, better fiber impregnation, and proper adhesion to the reinforcing fibers. This study, examined the fabrication of continuous fiber‐reinforced thermoset composites (CFTCs) using 3D printing technology. This investigation focused on the optimization of process parameters for UV‐curable composites. Using systematic experimentation, the proper nozzle diameter (2.0 mm), print thickness (0.6 mm), and print speed (200 mm/min) were determined, resulting in the attainment of optimal fiber weight ratio and impregnation. The optimized CFTC exhibited an exceptional ultimate tensile strength of 276.26 MPa, exceeding existing literature data on printed short fiber composites. Additionally, under flexural loading conditions, an ultimate strength of 76.7 MPa was observed, which is characterized by a more ductile failure than a brittle fracture mode. The results of this research demonstrate the significant potential of 3D‐printed CFTCs and establish a robust process window for achieving exceptional mechanical properties. These findings hold promise for a wide range of applications demanding high‐strength composite materials.Highlights Continuous fiber reinforced thermoset composites successfully printed. Determination of a process window for printed CFTCs. The optimized CFTC exhibited a remarkable ultimate tensile strength of 276.26 MPa. Ultimate strength of 76.7 MPa was achieved under flexural loading.

Recent progress in thermal and acoustic properties of natural fiber reinforced polymer composites: Preparation, characterization, and data analysis

AbstractNatural fiber reinforced polymer composites (NFRPCs) have emerged as promising eco‐friendly alternatives over conventional synthetic fiber composites due to their inherent biodegradability, renewability, low environmental impact, and lightweight properties. It has been seen a significant growth in both invention and innovation in the field of NFRPCs. Natural fibers (NFs) reduce the cost of the material by 5%, the weight of the composite by 10%, and the energy required for production by 80%. In terms of thermal, and acoustic properties, NFs can successfully compete with synthetic fibers. As a result, the development of NFRPCs for industrial use has increased significantly in the past decade to meet the growing demands of industrial sectors. To improve the thermal and acoustic properties of NFRPCs, researchers have done a lot of investigation. The aim of the current review is to provide a comprehensive analysis of the existing literature on the thermal and acoustic properties of natural fiber reinforced polymer composites. Thermal properties such as thermal conductivity, TGA, DSC, DMA, and acoustic properties of natural fiber reinforced composites with several parameters, such as different fiber types, different matrix types, fiber weight ratio, fiber to matrix ratio, chemical treatment of fiber have been summarized and analyzed very concisely. This review also emphasizes a summary of different natural fibers, their chemical compositions, composite preparation, characterizations, and future research directions. This article enables the readers, researchers, and manufacturers to realize several opportunities about the latest developments in NFRPCs for the application of thermal and acoustic purposes.Highlights Natural fibers can successfully compete with synthetic fibers, in terms of thermal and acoustic properties. Thermal properties of natural fiber reinforced composites including thermal conductivity, TGA, DSC, and DMA are summarized. Acoustic properties of natural fiber reinforced polymer composites are discussed. Composite materials made of treated fibers result better thermal stability than untreated fiber composites. Sound absorption coefficient generally increases as fiber content increases.

Effect of Hybridization of Ramie Fibers on the Vibrational and Damping Responses of Ramie/Glass/Epoxy Resin Composite Laminates

Fiber reinforced polymer composites made with glass fibers are among the oldest and most popular kinds of composites in use today. Glass fiber reinforced composites' key benefits are their adaptability for specific material applications, which allows them to give a number of design advantages relating to strength, chemical stability, impact damage tolerance, heat insulation, and low cost. The focus of this research is to investigate the role of hybridized ramie fibers in the assessment of enhanced vibrational damping capabilities in fiber glass reinforced composites, as well as in the initial assessment to verify their acceptability for real-time applications. Composite molding employing the hand layup technique was used to fabricate hybrid epoxy composites with ramie to glass fiber weight ratios from 0 to 50%. A free vibration test was performed to determine the hybrid composite's vibration dampening capabilities as a function of the ramie fiber filler content. The results demonstrated that the damping ratio was reduced when the percentage of ramie fiber in the GFRP composite was raised from 10% weight to about 50% weight. But adding up to 40% wt of ramie fiber to the hybrid composite had the biggest effect on the damping ratio, natural frequency, storage modulus, and loss modulus. This means that using ramie fiber in hybrid composites will be cost-effective and good for the environment.

Influence of hemicellulose and lignin on intermolecular interaction between quinacridone and lignocellulosic fibers revealed by gel-state NMR and color measurements

Quinacridone, a π-conjugated planar molecule, and common red pigment in industrial and painting applications, easily aggregates to form large clusters of pigment particles, resulting in a reduction in color strength. Cotton-derived cellulose nanofiber (NF), which almost consists of cellulose without hemicellulose and lignin, has been found to adsorb quinacridone on the surface, which inhibits pigment aggregation. The aggregation inhibition property of cellulose NF was induced by the strong intermolecular interactions between cellulose and quinacridone. In this study, the properties of lignocellulosic fibers for suppressing the aggregation of quinacridone pigments were investigated to reveal the influence of hemicellulose and lignin on the intermolecular interactions between quinacridone and fibers. Two lignocellulosic fibers with different degrees of fibrillation were used as dispersants of the pigment. In the scanning electron microscopy (SEM) images of the quinacridone–lignocellulose mixture, quinacridone particles were observed along the lignocellulose fiber, indicating that the quinacridone particles were well-adsorbed on the fiber surface. Consequently, the color of the aqueous suspension of quinacridone–lignocellulose mixture became increasingly vivid as the weight ratio of the lignocellulose fibers increased and as the fiber was fibrillated. The nuclear Overhauser effect spectroscopy (NOESY)–nuclear magnetic resonance (NMR) spectrum for quinacridone–lignocellulose suspension in d-dimethyl sulfoxide showed several NOE cross-peaks between quinacridone and cellulose/hemicellulose, whereas no cross-peaks between quinacridone and lignin were observed. It can be concluded that cellulose and hemicellulose promote the adsorption of quinacridone on the fiber surface, whereas lignin does not interact with quinacridone, even though both are aromatic molecules. This suggests that the intermolecular interactions based on hydrogen bonding and CH–π attraction are more dominant than the π–π attraction between quinacridone and lignocellulosic fibers.

Mapping the progress in natural fiber reinforced composites: Preparation, mechanical properties, and applications

AbstractExploration of natural fiber‐reinforced polymer composites (NFRPCs) in cutting‐edge applications is due to phenomenal properties, such as lightweight, low‐cost, and environmental aspects. NFs can effectively compete to the synthetic fibers in terms of mechanical, thermal and acoustic properties. As a result, the invention and innovation of natural fiber (NF) composites for commercial purposes has increased dramatically in recent years to meet the growing demand of the industrial sectors. Materials are the cornerstone of any manufacturing industry. NFRPCs are a good alternative to conventional materials because of their relatively high mechanical properties and lower production energy. NFs decrease the cost of the material by 5% while reducing the weight of the composite by 10% and the manufacturing energy by 80%. A lot of work has been done to enhance NFRPCs' mechanical properties to overcome their drawbacks, such as poor fiber‐to‐matrix adhesion, thermal stability, and moisture absorption. However, for better mechanical properties, it is crucial to understand the fibers' embedded manufacturing technique and the appropriate fiber weight percentage with appropriate matrix. This review article discusses composites made of NFs providing a comprehensive and up‐to‐date overview of the field of NFRPCs, focusing on recent advancements in preparation techniques, improvements in mechanical properties such as tensile, flexural and impact strength of NFRPCs with various fiber types, fiber weight ratio, fiber‐to‐matrix ratio for appropriate engineering applications, and elucidating future research directions by analyzing trends and challenges in the field. The aim of this review article is to provide a deep evaluation of the progress made in the field of NFRPCs, with the ultimate goal of advancing knowledge and understanding of this field.

Experimental investigation on mechanical and tribological characteristics of snake grass/sisal fiber reinforced hybrid composites

Abstract An experiential research on mechanical and tribological characteristics of snake grass and sisal fiber reinforced hybrid polymer (epoxy) composites was carried out and reported in this article. The snake grass and sisal fibers were initially treated with 5% sodium hydroxide (NaOH). Hybrid composite samples were fabricated using a compression moulding technique with a total fiber weight ratio of 30% and an epoxy resin weight ratio of 70%. The proportions of snake grass and sisal fibers in the hybrid composites were 70:30, 50:50, and 30:70. The fabricated hybrid composite samples were subjected to flexural, tensile, interlaminar shear strength, Shore D hardness, water absorption, and wear tests as per ASTM international standards, and the outcomes were compared with the results of snake grass and sisal mono fiber composites. The results disclosed that the 30:70 (SG:S) hybrid composite has higher mechanical characteristics than those of other hybrid and mono fiber composites. Also, the 30:70 hybrid sample performed at par with the sisal mono composite in wear and water absorption characteristics. Optical microscopy examination of alkali-treated natural hybrid and mono fiber composites displayed excellent results in terms of interfacial bonding between polymer and fiber.

An evaluation on mechanical properties of vaccum bagging processed kenaf epoxy nano aluminium oxide and nanographene composites

This paper aims to study the mechanical properties of hybrid polymer composites and the addition of primary and secondary fillers the nano-aluminum oxide and nanographene to the Kenaf epoxy composites. The vacuum bagging method was used to fabricate the composites. The advantage of using vacuum bagging is to reduce blowholes. The weight ratio of Kenaf fiber 50%–60%, matrix 40%, fillers nano-aluminum oxide 0%–6%, and nanographene 0%–3% was considered. Mechanical properties like Tensile strength, Young’s modulus and elongation, flexural strength, flexural modulus, hardness, impact strength, and compression strength were tested.6% nano aluminum oxide and 3% nanographene show a 125% increase in tensile strength, a 45% increase in flexural strength, and almost four times higher flexural modulus recorded. 42% increase in compression strength, and an increase of 40% in impact strength. The highest Vickers hardness is 27. An increase in primary and secondary fillers decreases and a combination of increases the mechanical properties.

Effect of nanoparticles in natural fiber reinforced polymer composites

Fiber surface modifications by chemical treatment and matrix modification with nanofillers are two key techniques used in recent times to improve the natural fiber reinforced polymer composite strength. The impact of titanium dioxide (TiO2), magnesium oxide (MgO), and zinc oxide (ZnO) nanoparticles on the mechanical properties of 6% sodium hydroxide alkali treated kenaf fiber reinforced epoxy composites has been experimentally examined and reported in this research article. All the composite samples were fabricated using vacuum bagging technique, with 35% Fiber weight ratio. The nanofillers were added in 3% weight proportion of total composite weight using ultrasonication method. According to ASTM standards, the prepared samples were evaluated for tensile, flexural, and impact strength. The experimental results showed that, 6% NaOH treatment on kenaf fibers showed 11.2%, 24.9%, 8.4%, and 28.7% improvement on tensile strength, modulus, flexural and impact strength respectively. The addition of different nano particles in the matrix phase performed well on effective stress transfer between fiber layers through matrix layers, hence improvement on mechanical properties were noted.

Study of Properties of Polyethylene Glycol and Its Glass Fibers Composites under UV-Rad for Oils Filtration Applications

This study determines the effects of UV radiation and heat treatment on many flow and mechanical parameters of PEG 4000, including flow time and viscosity (specific, reduced, relative, and intrinsic). Solubility time and shore D hardness are among the mechanical characteristics. By adjusting the concentrations of solutions in the range (0.01–0.03) g/ml of heating and non-heating PEG powders, and examining the polymer's solubility at the same time, the flow characteristics of the polymer are explored. Random glass fiber reinforcement in the range of 0.1–0.4 wt has also been studied to indicate the effect on shore hardness. After exposing the produced plates to ultraviolet light, the efficacy of the plates in purifying the oil from contaminants was investigated. The results show that increasing the concentration increases all types of viscosity and flow time, with the exception of intrinsic viscosity, which decreases as concentrations increase. Other parameters decrease after the first UV ray and heat treatment, but increase as the time of UV ray treatment increases. Furthermore, increasing the weight ratio of glass fibers from 0.1 to 0.4 wt lowered shore hardness, whereas increasing the weight ratio at the same previous range increased it after UV rad. While solubility data refers to increasing polymer weight and radiation help increase solubility time. The filtration efficacy of the small particles of the produced filters increased after the overlapping plates were exposed to UV radiation, owing to the smaller pore diameters.

Perilaku Hambatan Panas pada Papan Partisi diperkuat Serat Tandan Kosong Kelapa Sawit

The goal of this research was to determine the heat resistance behavior of polymer composite fiber boards with oil palm empty fruit bunches (OPEFB) fillers as influenced by mass density and water absorption, with the hope that partition boards with OPEFB fiber fillers could reduce the heat entering the room from outside vines through directly exposed walls. The partition board under discussion is a heat insulator with a thermal conductivity test impacted by the mass density of the composite. The test method used is ASTM-C-177-2013, which consists of measuring heat propagation by modifying a 40-watt heat source and testing specimens from polymer composite partition boards formed based on standards obtained from partition forming boards with a matrix of polyester resin SHCP 2667 WNC fraction weight with a fiber weight ratio of 25 wt.%, 30 wt.%, and 35 wt.% randomly arranged (chopped strand mat/CSM). The highest thermal conductivity value was observed in a 25 wt.% fiber weight ratio of 0.141 W/m. o C at a void percentage of 7.65% for a 5 minutes test time; 0.146 W/m. o C for a 10 minutes test time; 0.151 W/m. o C for 15 minutes test time at a mass density of 1.16 gr/cm. While the 35 wt.% fiber weight ratio has the lowest thermal conductivity value of 0.137 W/m. o C at a void percentage of 4.24% for a 5 minutes test time; 0.142 W/m. o C for a 10 minutes test time; and 0.147 W/m. o C for a 15 minutes test time at a mass density of 1.24 gr/cm 3 and a water absorption capacity of 3.75%. According to the investigation’s findings, the higher the water absorption capacity, the higher the thermal conductivity of the partition board, and the higher the mass density, the lower the thermal conductivity. As a result, the lower the value of the thermal conductivity of the partition board, the better the insulating properties.

Mechanical Behaviors of Microwave-Assisted Pyrolysis Recycled Carbon Fiber-Reinforced Concrete with Early-Strength Cement

This study aimed to investigate the mechanical performance of early-strength carbon fiber-reinforced concrete (ECFRC) by incorporating original carbon fiber (OCF), recycled carbon fiber (RCF), and sizing-removed carbon fiber (SCF). Compressive, flexural, and splitting tensile strength were tested under three fiber-to-cement weight ratios (5‱, 10‱, and 15‱). The RCF was produced from waste bicycle parts made of carbon fiber-reinforced polymer (CFRP) through microwave-assisted pyrolysis (MAP). The sizing-removed fiber was obtained through a heat-treatment method applied to the OCF. The results of scanning electron microscopy (SEM) analysis with energy dispersive X-ray spectrometry (EDS) indicated the successful removal of sizing and impurities from the surface of the RCF and SCF. The mechanical test results showed that ECFRC with a 10‱ fiber-to-cement weight ratio of carbon fiber had the greatest improvement in its mechanical strengths. Moreover, the ECFRC with 10‱ RCF exhibited higher compressive, flexural, and splitting tensile strength than that of benchmark specimen by 14.2%, 56.5%, and 22.5%, respectively. The ECFRC specimens with a 10‱ fiber-to-cement weight ratio were used to analyze their impact resistance under various impact energies in the impact test. At 50 joules of impact energy, the impact number of the ECFRC with SCF was over 23 times that of the benchmark specimen (early-strength concrete without fiber) and was also greater than that of ECFRC with OCF and RCF.