Kenaf Fibrous Concrete: Mechanical Properties with Different Fiber Volume Fraction

2018 ◽  
Vol 8 (4) ◽  
pp. 1036 ◽  
Author(s):  
Norazura Mizal Azzmi ◽  
Jamaludin Mohamad Yatim
Keyword(s):  
Mechanical Properties ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Volume ◽  
Fibrous Concrete ◽  
Concrete Mechanical Properties

Monitoring of mechanical properties of prestressed glass fiber epoxy composites over 12 months after fabrication

2021 ◽  
pp. 002199832110047
Author(s):  
Mahmoud Mohamed ◽  
Siddhartha Brahma ◽  
Haibin Ning ◽  
Selvum Pillay
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Flexural Strength ◽  
Compressive Residual Stress ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Epoxy Composites ◽  
Flexural Properties ◽  
Initial Increase ◽  
Fiber Volume

Fiber prestressing during matrix curing can significantly improve the mechanical properties of fiber-reinforced polymer composites. One primary reason behind this improvement is the generated compressive residual stress within the cured matrix, which impedes cracks initiation and propagation. However, the prestressing force might diminish progressively with time due to the creep of the compressed matrix and the relaxation of the tensioned fiber. As a result, the initial compressive residual stress and the acquired improvement in mechanical properties are prone to decline over time. Therefore, it is necessary to evaluate the mechanical properties of the prestressed composites as time proceeds. This study monitors the change in the tensile and flexural properties of unidirectional prestressed glass fiber reinforced epoxy composites over a period of 12 months after manufacturing. The composites were prepared using three different fiber volume fractions 25%, 30%, and 40%. The results of mechanical testing showed that the prestressed composites acquired an initial increase up to 29% in the tensile properties and up to 32% in the flexural properties compared to the non-prestressed counterparts. Throughout the 12 months of study, the initial increase in both tensile and flexural strength showed a progressive reduction. The loss ratio of the initial increase was observed to be inversely proportional to the fiber volume fraction. For the prestressed composites fabricated with 25%, 30%, and 40% fiber volume fraction, the initial increase in tensile and flexural strength dropped by 29%, 25%, and 17%, respectively and by 34%, 26%, and 21%, respectively at the end of the study. Approximately 50% of the total loss took place over the first month after the manufacture, while after the sixth month, the reduction in mechanical properties became insignificant. Tensile modulus started to show a very slight reduction after the fourth/sixth month, while the flexural modulus reduction was observed from the beginning. Although the prestressed composites displayed time-dependent losses, their long-term mechanical properties still outperformed the non-prestressed counterparts.

Performance of Bamboo Fiber Reinforced Composites: Mechanical Properties

2021 ◽  
Vol 879 ◽  
pp. 284-293
Author(s):  
Norliana Bakar ◽  
Siew Choo Chin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Vinyl Ester ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Bamboo Fiber ◽  
Synthetic Fiber ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Volume Fractions

Fiber Reinforced Polymer (FRP) made from synthetic fiber had been widely used for strengthening of reinforced concrete (RC) structures in the past decades. Due to its high cost, detrimental to the environment and human health, natural fiber composites becoming the current alternatives towards a green and environmental friendly material. This paper presents an investigation on the mechanical properties of bamboo fiber reinforced composite (BFRC) with different types of resins. The BFRC specimens were prepared by hand lay-up method using epoxy and vinyl-ester resins. Bamboo fiber volume fractions, 30%, 35%, 40%, 45% and 50% was experimentally investigated by conducting tensile and flexural test, respectively. Results showed that the tensile and flexural strength of bamboo fiber reinforced epoxy composite (BFREC) was 63.2% greater than the bamboo fiber reinforced vinyl-ester composite (BFRVC). It was found that 45% of bamboo fiber volume fraction on BFREC exhibited the highest tensile strength compared to other BFRECs. Meanwhile, 40% bamboo fiber volume fraction of BFRVC showed the highest tensile strength between bamboo fiber volume fractions for BFRC using vinyl-ester resin. Studies showed that epoxy-based BFRC exhibited excellent results compared to the vinyl-ester-based composite. Further studies are required on using BFRC epoxy-based composite in various structural applications and strengthening purposes.

Effects of Fiber Volume Fraction on Mechanical Properties of SiC-Fiber/Si3N4-Matrix Composites

1994 ◽  
Vol 77 (7) ◽  
pp. 1897-1900 ◽  
Author(s):  
Hockin H. K. Xu ◽  
Claudia P. Ostertag ◽  
Linda M. Braun ◽  
Isabel K. Lloyd
Keyword(s):  
Mechanical Properties ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Matrix Composites ◽  
Fiber Volume ◽  
Sic Fiber ◽  
Si3n4 Matrix

Influence of fiber volume fraction and curing temperature on mechanical properties of jute/PLA green composites

2019 ◽  
Vol 28 (4) ◽  
pp. 273-284
Author(s):  
Jai Inder Preet Singh ◽  
Sehijpal Singh ◽  
Vikas Dhawan
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Fiber Volume Fraction ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Matrix Material ◽  
Research Work ◽  
Curing Temperature ◽  
Green Composites ◽  
Fiber Volume

Rising environmental concerns and depletion of petrochemical resources have resulted in an increased interest in biodegradable natural fiber-reinforced polymer composites. In this research work, jute fiber has been used as a reinforcement and polylactic acid (PLA) as the matrix material to develop jute/PLA green composites with the help of compression molding technique. The effect of fiber volume fraction ranging from 25% to 50% and curing temperature ranging from 160°C to 180°C on different samples were investigated for mechanical properties and water absorption. Results obtained from various tests indicate that with an increase in the fiber volume fraction, tensile and flexural strength increases till 30% fiber fraction, thereafter decreases with further increase in fiber content. Maximum tensile and flexural strength of jute/PLA composites was obtained with 30% fiber volume fraction at 160°C curing temperature. The trend obtained from mechanical properties is further justified through the study of surface morphology using scanning electron microscopy.

scholarly journals Peningkatan Sifat Mekanik Komposit Serat Alam Limbah Sabut Kelapa (Cocofiber) yang Biodegradable

2021 ◽  
Vol 6 (1) ◽  
pp. 30-37
Author(s):  
Sri Hastuti ◽  
Herru Santosa Budiono ◽  
Diki Ilham Ivadiyanto ◽  
Muhammad Nurdin Nahar
Keyword(s):  
Mechanical Properties ◽  
Fiber Volume Fraction ◽  
Bending Strength ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Composites ◽  
Coconut Fiber ◽  
Fiber Volume ◽  
Coconut Coir ◽  
The Impact

Inovasi baru serat dari sabut kelapa dimanfaatkan untuk meningkatkan nilai ekonomis dari serat sabut kelapa, oleh karena itu dirancanglah pendayagunaan serat dari sabut kelapa untuk penguat komposit dengan material serat alam yang biodegradable. Hal ini untuk mendukung penggunaan komposit yang ramah terhadap lingkungan dan mengurangi penggunaan material komposit serat sintetis yang polutan. Tujuan penelitian adalah menganalisis sifat mekanik pada komposit serat alam bermaterial serat dari sabut kelapa yang ramah lingkungan. Metode penelitian pembuatan komposit berpenguat serat dari sabut kelapa dilakukan treatment NaOH 15% selama 5 jam dan fraksi volume serat 10 %, 15 %, dan 20 %. Komposit  serat dari sabut kelapa dengan matriks UPRs 157 BQTN dengan hardener MEXPO. Pengujian mekanik dilakukan uji bending menggunakan standar ASTM D790 dan uji impak  menggunakan standar ASTM D5941.  Pengujian impak komposit serat alam menunjukkan ketangguhan impak komposit pada fraksi volume serat 20% dengan nilai 0.017588J/mm2. Hasil pengujian menunjukkan peningkatan fraksi volume serta berpengaruh terhadap peningkatan kekuatan bending komposit serat dari sabut kelapa  dengan kekuatan optimum bending pada fraksi volume serat 10% dengan nilai 44,33N/mm2. Hal ini menunjukkan peningkatan fraksi volume serat dengan perendaman NaOH 15% akan meningkatkan sifat mekanik bending dan impak komposit. Perendaman NaOH memberikan pengaruh daya serap sabut kelapa terhadap matrik Unsaturated Polyester yang dapat meningkatkan daya rekat antara penguat serat dengan matrik sehingga meningkatkan sifat mekanik bending dan impak komposit. ABSTRACT The innovation of coco fiber is used to increase the economic value of coconut coir, therefore the utilization of coconut fiber for reinforcing composites with biodegradable natural fiber material is designed. This is to support the use of composites that are friendly to the environment and reduce the use of pollutant synthetic fiber composite materials. The research objective was to analyze the mechanical properties of natural fiber composites with environmentally friendly coconut fiber as material. The research method of making fiber-reinforced composites from coconut coir was carried out by 15% NaOH treatment for 5 hours and a fiber volume fraction of 10%, 15%, and 20%. Composite fiber from coconut coir with UPRs 157 BQTN matrix with MEXPO hardener. Mechanical testing is carried out using the ASTM D790 standard and the impact test using the ASTM D5941 standard. The impact test of natural fiber composites showed the impact toughness of the composite at a fiber volume fraction of 20% with a value of 0.017588 J/ mm2. The test results showed an increase in volume fraction and an effect on the increase in the bending strength of coconut fiber composites with the optimum bending strength at a fiber volume fraction of 10% with a value of 44.33N /mm2. This shows that the increase in fiber volume fraction by immersion in 15% NaOH will increase the bending mechanical properties and the impact of the composite. Soaking NaOH has an effect on the absorption power of coconut coir on the Unsaturated Polyester matrix which can increase the adhesion between the fiber reinforcement and the matrix thereby increasing the bending mechanical properties and impact of the composite.

scholarly journals Investigation on the Mechanical Properties of Fiber Reinforced Recycled Concrete

2016 ◽  
Vol 2 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Hasan Jalilifar ◽  
Fatholla Sajedi ◽  
Sadegh Kazemi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Experimental Test ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Content ◽  
Recycled Concrete ◽  
Test Results ◽  
Fiber Volume ◽  
Flexural Toughness

The flexural strength of conventional concrete material is known to be enhanced by incorporating a moderate volume-fraction of randomly distributed fibers. However, there is limited information on describing the influence of fiber volume-fraction on the compressive and flexural strength of recycled coarse aggregate concrete (RCA-C) material. This paper reports on experimental test results of the RCA-C material replaced with 0, 30, 50 and 100% recycled aggregate and 0, 0.5, 1 and 1.5% steel fiber volume fraction. Three-point flexural tests of notched prism specimens were completed. The mechanical properties in compression were characterized using cube specimens. Significant improvement in compressive and flexural strength of RCA-C was found as fiber content increased from 0 to 1.5%. The experimental test results of RCA-C were further evaluated to investigate the influence of fiber content on flexural toughness. According to test results, the addition of steel fibers to RCA-C material appreciably increased the flexural toughness.

Effect of fiber prestressing on mechanical properties of glass fiber epoxy composites manufactured by vacuum-assisted resin transfer molding

2019 ◽  
Vol 39 (1-2) ◽  
pp. 21-30
Author(s):  
Mahmoud Mohamed ◽  
Mohamed M Selim ◽  
Haibin Ning ◽  
Selvum Pillay
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Fiber Waviness ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites

The mechanical properties of fiber-reinforced polymer composites depend on several aspects such as the characteristics of constituents, fiber volume fraction, and manufacturing techniques. Fiber prestressing is considered a very attractive manufacturing technique that can be used to produce fiber-reinforced polymer composites with high mechanical properties. This technique has the potential to eliminate or reduce some manufacturing problems like fiber waviness. In the present study, a new approach was used to prepare prestressed fiber-reinforced polymer composites. Unidirectional E-glass fiber-stitched mats were impregnated with epoxy matrix through vacuum-assisted resin transfer molding process. Once the infusion was done, a pre-calculated tensile force was applied to the fiber mats through a hydraulic tensile machine. The impregnated fiber mats were left under tension and vacuum during curing of the epoxy matrix (24 h). Five prestressed samples were prepared by using five different prestressing levels 20, 40, 60, 80, and 100 MPa. In addition, non-prestressed (control) sample was prepared for the purpose of comparison. The influence of fiber prestressing on fiber waviness, fiber volume fraction, and void content was investigated. Flexural, tensile, and compression tests were performed to observe the effect of fiber prestressing on the mechanical properties. The results have shown the success of this new approach in producing prestressed fiber-reinforced polymer composites with high mechanical properties comparing to non-prestressed composites. The microstructure analysis has shown dramatical reduction in fiber waviness for the prestressed samples over control sample. All prestressed samples have shown higher fiber volume fraction and lower void content comparing to the control sample. Also the results have shown as the prestressing level increases, fiber volume fraction increase and void content decreases. Prestressing levels of 40 and 60 MPa were found to be the best candidates, they have led to an increase in tensile strength, compressive strength, and flexural strength by 24.2%, 72.5%, 28% and 28.6%, 100.4%, 26.1%, respectively, comparing to the non-prestressed sample. Ease of implementation and promising results of this new approach would attract the attention toward it. Automotive industry is one potential nominee to apply this approach during manufacturing of fiber-reinforced polymer leaf spring.

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