Rheological, mechanical properties, and statistical significance analysis of shotcrete with various natural fibers and mixing ratios

The addition of natural fibers used as reinforcement has great appeal in the construction materials industry since natural fibers are cheaper, biodegradable, and easily available. In this work, we analyzed the feasibility of using the fibers of piassava, tucum palm, razor grass, and jute from the Amazon rainforest as reinforcement in mortars, exploiting the mechanical properties of compressive and flexural strength of samples with 1.5%, 3.0%, and 4.5% mass addition of the composite binder (50% Portland cement + 40% metakaolin + 10% fly ash). The mortars were reinforced with untreated (natural) and treated (hot water treatment, hornification, 8% NaOH solution, and hybridization) fibers, submitted to two types of curing (submerged in water, and inflated with CO2 in a pressurized autoclave) for 28 days. Mortars without fibers were used as a reference. For the durability study, the samples were submitted to 20 drying/wetting cycles. The fibers improved the flexural strength of the mortars and prevented the abrupt rupture of the samples, in contrast to the fragile behavior of the reference samples. The autoclave cure increased the compressive strength of the piassava and tucum palm samples with 4.5% of fibers.

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The Structure and Mechanical Properties of Hemp Fibers-Reinforced Poly(ε-Caprolactone) Composites Modified by Electron Beam Irradiation

Applied Sciences ◽

10.3390/app11125317 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5317

Author(s):

Rafał Malinowski ◽

Aneta Raszkowska-Kaczor ◽

Krzysztof Moraczewski ◽

Wojciech Głuszewski ◽

Volodymyr Krasinskyi ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Electron Beam ◽

Impact Strength ◽

Flexural Modulus ◽

Natural Fibers ◽

High Energy ◽

Electron Radiation ◽

Elongation At Break ◽

Hemp Fibers

The need for the development of new biodegradable materials and modification of the properties the current ones possess has essentially increased in recent years. The aim of this study was the comparison of changes occurring in poly(ε-caprolactone) (PCL) due to its modification by high-energy electron beam derived from a linear electron accelerator, as well as the addition of natural fibers in the form of cut hemp fibers. Changes to the fibers structure in the obtained composites and the geometrical surface structure of sample fractures with the use of scanning electron microscopy were investigated. Moreover, the mechanical properties were examined, including tensile strength, elongation at break, flexural modulus and impact strength of the modified PCL. It was found that PCL, modified with hemp fibers and/or electron radiation, exhibited enhanced flexural modulus but the elongation at break and impact strength decreased. Depending on the electron radiation dose and the hemp fibers content, tensile strength decreased or increased. It was also found that hemp fibers caused greater changes to the mechanical properties of PCL than electron radiation. The prepared composites exhibited uniform distribution of the dispersed phase in the polymer matrix and adequate adhesion at the interface between the two components.

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Valorization of Invasive Plants from Macaronesia as Filler Materials in the Production of Natural Fiber Composites by Rotational Molding

Polymers ◽

10.3390/polym13132220 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2220

Author(s):

Zaida Ortega ◽

Francisco Romero ◽

Rubén Paz ◽

Luis Suárez ◽

Antonio Nizardo Benítez ◽

...

Keyword(s):

Mechanical Properties ◽

Invasive Plant ◽

Natural Fiber ◽

Ricinus Communis ◽

Local Level ◽

Natural Fibers ◽

Fiber Composites ◽

Filler Materials ◽

Natural Fiber Composites ◽

Rotational Molding

This paper compares the mechanical properties of different natural fiber composites produced by rotational molding as a way of waste valorization from campaigns to control invasive plant species in Macaronesia. Rotomolded parts produced with polymeric matrices (polyethylene) and filled with up to 20% by weight of cellulosic fibers obtained from Arundo donax L., Pennisetum setaceum, and Ricinus communis plants were characterized in terms of tensile, flexural, and impact strength. It was found that the sieving of natural fibers allowed for their introduction in higher loadings, from 10 (for un-sieved material) to 20%; fiber size greatly affected the mechanical properties of the final parts, although some combinations were proven not to reduce the mechanical properties of the neat resin. This study is a first approach to the valorization of residues obtained from periodic campaigns of the control of invasive species performed by public authorities, usually at the local level. It is important to highlight that the main objective of this research did not focus on economically profitable activity; instead, it was focused on the reduction of wastes to be disposed from ecosystem maintenance actions and the investment of potential income into preservation policies.

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Chemical Composition of Natural Fibers and its Influence on their Mechanical Properties

Mechanics of Composite Materials ◽

10.1007/s11029-014-9422-2 ◽

2014 ◽

Vol 50 (3) ◽

pp. 359-376 ◽

Cited By ~ 79

Author(s):

A. Komuraiah ◽

N. Shyam Kumar ◽

B. Durga Prasad

Keyword(s):

Mechanical Properties ◽

Chemical Composition ◽

Natural Fibers

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A statistical analysis of low-stress mechanical properties of warp-knitted fabrics

Textile Research Journal ◽

10.1177/0040517516681963 ◽

2016 ◽

Vol 88 (4) ◽

pp. 467-479 ◽

Cited By ~ 3

Author(s):

Ka-yan Yim ◽

Chi-wai Kan

Keyword(s):

Mechanical Properties ◽

Evaluation System ◽

Natural Fibers ◽

Physical Parameters ◽

Knitted Fabrics ◽

Fabric Hand ◽

Low Stress Mechanical Properties ◽

Fabric Weight ◽

Fabric Structures ◽

Selection Of

Fabric hand is an indispensable characteristic for the selection of fabric and product development and the buying consideration for manufacturers and consumers. However, there is little comprehensive work on the hand feel property of warp-knitted fabrics due to the mainstream natural fibers (cotton, wool and silk) and other fabric structures (woven, weft-knitted and nonwoven). The increasing potential for the wide variety of applications and development of warp-knitted fabrics is not only because its fabric hand gives better determination for fabric marketing, but also because it provides extensive scope for fabric performance and appearance. This paper reports an experimental study on the integrated fabric hand behavior of a series of warp-knitted fabrics made for various apparel applications, such as sportswear, lingerie and leisure wear. These 105 fabrics were produced by varying different physical parameters, including fabric weight and fabric thickness. The Kawabata Evaluation System for Fabric (KES-F) was employed to obtain the fabric hand properties (primary hand value and total hand value) related with stiffness, smoothness and softness. All low-stress mechanical properties and fabric hand values from the testing results were used to verify the applicability of the KES-F on warp-knitted fabrics and to analyze the relationships of fabric parameters and hand characteristics. The results indicate that the KES-F is an appropriate tool to measure the hand attributes of warp-knitted samples, and moderate correlations between physical properties and mechanical behavior were found.

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Influence of supplementary cementitious materials, curing conditions and mixing ratios on fresh and mechanical properties of engineered cementitious composites – A review

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.125038 ◽

2021 ◽

Vol 309 ◽

pp. 125038

Author(s):

N. Shanmugasundaram ◽

S. Praveenkumar

Keyword(s):

Mechanical Properties ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Cementitious Composites ◽

Engineered Cementitious Composites ◽

Curing Conditions ◽

Mixing Ratios

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Characterization of particleboard made from oil heat-treated rubberwood particles at different mixing ratios

BioResources ◽

10.15376/biores.15.3.6795-6810 ◽

2020 ◽

Vol 15 (3) ◽

pp. 6795-6810

Author(s):

Nurul Fatiha Osman ◽

Paimon Bawon ◽

Seng Hua Lee ◽

Pakhriazad Hassan Zaki ◽

Syeed SaifulAzry Osman Al-Eldrus ◽

...

Keyword(s):

Mechanical Properties ◽

Oil Content ◽

Urea Formaldehyde ◽

Physical And Mechanical Properties ◽

Thermal Characterization ◽

High Dimensional ◽

Mixing Ratios ◽

Uf Resin ◽

Heat Treated

Particleboard was produced by mixing oil heat-treated rubberwood particles at different ratios, with the goal of achieving high dimensional stability. Rubberwood particles were soaked in palm oil for 2 h and heat treated at 200 °C for 2 h. The treated particles were soaked in boiling water for 30 min to remove oil and were tested for chemical alteration and thermal characterization via Fourier-transform infrared spectroscopy and thermogravimetric analysis. Particleboard was fabricated by mixing treated rubberwood particles (30%, 50%, and 70%) with untreated particles (70%, 50%, and 30%, respective to previous percentages) and bonded with urea-formaldehyde (UF) resin. The results revealed that oil-heat treated particles had greater thermal stability than the untreated particles. The addition of oil heat treated particles improved the physical properties of the particleboard with no significant reduction in mechanical strength. However, this was only valid for ratios of 70% untreated to 30% treated and 50% untreated to 50% treated. When a ratio of 70% oil heat treated particles was used, both the physical and mechanical properties were reduced drastically, due to bonding interference caused by excessive oil content. Particleboard made with a ratio of 5:5 (treated to untreated) exhibited the best physical and mechanical properties.

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Development of Banana/Coir Natural Fibers Reinforced Polypropylene Hybrid Composites: The Effect of MA-g-PP (Maleic Anhydride Grafted Polypropylene) on Mechanical Properties and Thermal Properties

Nano Hybrids and Composites ◽

10.4028/www.scientific.net/nhc.32.85 ◽

2021 ◽

Vol 32 ◽

pp. 85-97

Author(s):

Gunturu Bujjibabu ◽

Vemulapalli Chittaranjan Das ◽

Malkapuram Ramakrishna ◽

Konduru Nagarjuna

Keyword(s):

Mechanical Properties ◽

Impact Strength ◽

Coupling Agent ◽

Mechanical Performance ◽

Hybrid Composites ◽

Natural Fibers ◽

Mechanical Tests ◽

Coir Fiber ◽

Banana Fiber ◽

C Fibers

Banana/Coir fiber reinforced polypropylene hybrid composites was formulated by using twin screw extruder and injection molding machine. Specimens were prepared untreated and treated B/C Hybrid composites with 4% and 8% of MA-g-PP to increase its compatibility with the polypropylene matrix. Both the without MA-g-PP and with MA-g-PP B/C hybrid composites was utilized and three levels of B/C fiber loadings 15/5, 10/10 and 5/15 % were used during manufacturing of B/C reinforced polypropylene hybrid composites. In this work mechanical performance (tensile, flexural and impact strengths) of untreated and treated (coupling agent) with 4% and 8% of MA-g-PP B/C fibers reinforced polypropylene hybrid composite have been investigated. Treated with MA-g-PP B/C fibers reinforced specimens explored better mechanical properties compared to untreated B/C fibers reinforced polypropylene hybrid composites. Mechanical tests represents that tensile, flexural and impact strength increases with increase in concentration of coupling agent compared to without coupling agent MA-g-PP hybrid composites . B/C fibers reinforced polymer composites exhibited higher tensile, flexural and impact strength at 5% of Banana fiber, 15% of fiber Coir in the presence of 8% of MA-g-PP compared to 4% of MA-g-PP and untreated hybrid composites. The percentage of water absorption in the B/C fibers reinforced polypropylene hybrid composites resisted due to the presence of coupling agent MA-g-PP and thermogravimetry analysis (TGA) also has done.

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Quantification and statistical significance analysis of group separation in NMR-based metabonomics studies

Chemometrics and Intelligent Laboratory Systems ◽

10.1016/j.chemolab.2011.08.009 ◽

2011 ◽

Vol 109 (2) ◽

pp. 162-170 ◽

Cited By ~ 43

Author(s):

Aaron M. Goodpaster ◽

Michael A. Kennedy

Keyword(s):

Statistical Significance ◽

Group Separation ◽

Significance Analysis

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Microstructure and Mechanical Properties of the Wide-Gap Region Brazed with Various Powder Mixing Ratios of Additive to Filler Metal Powders

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.118.479 ◽

2006 ◽

Vol 118 ◽

pp. 479-484 ◽

Cited By ~ 1

Author(s):

Yong Hwan Kim ◽

S.I. Kwun

Keyword(s):

Mechanical Properties ◽

Metal Powder ◽

Room Temperature ◽

Filler Metal ◽

Metal Powders ◽

Powder Mixing ◽

Factors Affecting ◽

Mixing Ratios ◽

Microstructure And Mechanical Properties ◽

Wide Gap

This study investigated the microstructure and mechanical properties of the wide-gap region brazed with various powder mixing ratios of additive powder (IN738) to filler metal powder (DF4B). The wide-gap brazing process was carried out in a vacuum of 2×10-5 torr at 1230°C for 1 hr. The microstructure of the brazed region was analyzed by FESEM and AES. The wide-gap region brazed with 60wt.% IN738 additive powder and 40 wt.% DF 4B filler metal powder had a microstructure consisting of Ni solid solution + γ' and (Cr, W)2B. The fracture strength of the wide-gap region brazed with 60 wt.% IN738 additive and 40 wt.% DF 4B powder was as high as 832 MPa at room temperature. It was found that the (Cr, W)2B and pores in the brazed region are important microstructural factors affecting the mechanical properties of the wide-gap brazed region.

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