scholarly journals Hemp Fiber Reinforced Red Mud/Fly Ash Geopolymer Composite Materials: Effect of Fiber Content on Mechanical Strength

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 511 ◽  
Author(s):  
Eyerusalem A. Taye ◽  
Judith A. Roether ◽  
Dirk W. Schubert ◽  
Daniel T. Redda ◽  
Aldo R. Boccaccini
Keyword(s):  
Fly Ash ◽  
Mechanical Strength ◽  
Red Mud ◽  
Fiber Reinforced ◽  
Brazilian Tensile Strength ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
The Matrix ◽  
Geopolymer Composites ◽  
Scanning Electron

Novel hemp fiber reinforced geopolymer composites were fabricated. The matrix was a new geopolymer based on a mixture of red mud and fly ash. Chopped, randomly oriented hemp fibers were used as reinforcement. The mechanical properties of the geopolymer composite, such as diametral tensile (DTS) (or Brazilian tensile) strength and compressive strength (CS), were measured. The geopolymer composites reinforced with 9 vol.% and 3 vol.% hemp fiber yielded average DTS values of 5.5 MPa and average CS values of 40 MPa. Scanning electron microscopy (SEM) studies were carried out to evaluate the microstructure and fracture surfaces of the composites. The results indicated that the addition of hemp fiber is a promising approach to improve the mechanical strength as well as to modify the failure mechanism of the geopolymer, which changed from brittle to “pseudo-ductile”.

Mix design and flexural toughness of PVA fiber reinforced fly ash-geopolymer composites

2017 ◽  
Vol 150 ◽  
pp. 179-189 ◽  
Author(s):  
Fang Xu ◽  
Xin Deng ◽  
Chao Peng ◽  
Jing Zhu ◽  
Jianping Chen
Keyword(s):  
Fly Ash ◽  
Mix Design ◽  
Fiber Reinforced ◽  
Flexural Toughness ◽  
Pva Fiber ◽  
Geopolymer Composites

Hemp Fiber Reinforced Geopolymer Composites: Effects of NaOH Concentration on Fiber Pre-Treatment Process

2020 ◽  
Vol 841 ◽  
pp. 166-170
Author(s):  
Phattharachai Maichin ◽  
Teewara Suwan ◽  
Peerapong Jitsangiam ◽  
Prinya Chindaprasirt
Keyword(s):  
Treatment Process ◽  
Solution Concentration ◽  
Alkaline Treatment ◽  
The Self ◽  
Hemp Fiber ◽  
Natural Materials ◽  
Hemp Fibers ◽  
Naoh Solution ◽  
Pre Treatment ◽  
Geopolymer Composites

High demand for using parts of natural materials, e.g., cores, fibers or leaves, as alternative additives are being increased. The main reasons are that natural materials can be served as renewable and eco-friendly choices such a sustainable development. Nevertheless, some limitations of applying those natural products, such as biodegradation, UV degradation, or weak bonding, are raised and need to be modified before further handling. One of the modification techniques for bio-based materials is chemical treatment by using alkaline solution (alkalization). Treatment process allows the plant's fiber to have fewer impurities as well as to increase the bonding on its contacting surface area. This research focuses on (i) effects of NaOH solution concentration on the pre-treatment properties of hemp fibers and (ii) self-treatment behavior of hemp fiber in geopolymer composites. The results show that the concentration of NaOH solution directly affected the pre-treatment process of hemp fiber as higher concentration from 1, 3, 5, 8, 10 to 12 Molar provided more vanishing level of fiber impurities, indicated by Contact Angle (CA) measurement and Fourier Transform Infrared (FT-IR) Spectroscopy analysis. With the concept of alkaline treatment, the self-treatment process was therefore applied for hemp fiber incorporated in alkaline-activated geopolymer matrix. The results illustrate the self-treatment behavior of hemp fiber in geopolymer composites, which could improve the final performances of the hardened products without conventional pre-treatment process.

Influence of Foaming Agent on Properties of Red Mud Lightweight Baking-Free Brick

2014 ◽  
Vol 541-542 ◽  
pp. 388-391
Author(s):  
Long Ma ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Red Mud ◽  
Micro Structure ◽  
Foaming Agent ◽  
Scanning Electron

Red mud lightweight baking-free brick was prepared by red mud, fly ash and cement, mixed with a certain amount of activator agent and foaming agent. The influence of foaming agent on properties of red mud lightweight baking-free brick was studied. The micro-structure of red mud lightweight baking-free brick was characterized by scanning electron microscopy (SEM). The results show that when the foaming agent content is 10ml, the sample with better performance obtained and the density is 423kg/m3, flexural strength is 0.49MPa and compressive strength is 1.87MPa.

scholarly journals Effect of fly ash particle reinfo rcement on microstructure, porosity and hardness in Al-(Si-Mg) cast composites

2017 ◽  
Vol 23 (1&2) ◽  
pp. 113 ◽  
Author(s):  
M.B. Harun ◽  
S.R. Shamsudin ◽  
H. Yazid ◽  
Z. Selamat ◽  
M.S. Sattar ◽  
...  
Keyword(s):  
Fly Ash ◽  
Casting Process ◽  
Matrix Alloy ◽  
Stir Casting ◽  
Image Analyzer ◽  
Microscopy Image ◽  
Optical Microscopy Image ◽  
Cast Composites ◽  
The Matrix ◽  
Scanning Electron

The microstructure of cast Al-4Si-Mg reinforcedwith fly ash particles at various particlecontents has been studied. The composites were fabricated by stir casting process andcharacterized by optical microscopy, image analyzer, scanning electron microscopy and hardness measurements. The results showed that particle contents affected to the presence oforosities and hardness of the composites. It was observed that increasing the fly ash contentincrease the porosity in the composites, with the matrix alloy reinforced with 15 wt.% of fly ash particles having the highest porosity and lowest hardness.

scholarly journals Development of Abaca Fiber-reinforced Foamed Fly Ash Geopolymer

2018 ◽  
Vol 156 ◽  
pp. 05018 ◽  
Author(s):  
Ngo Janne Pauline S. ◽  
Promentilla Michael Angelo B.
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Materials ◽  
Curing Temperature ◽  
Sustainable Construction ◽  
Environmental Footprint ◽  
Fiber Reinforced ◽  
Foaming Agent ◽  
Fiber Loading ◽  
Geopolymer Composites

The growing environmental and economic concerns have led to the need for more sustainable construction materials. The development of foamed geopolymer combines the benefit of reduced environmental footprint and attractive properties of geopolymer technology with foam concrete’s advantages of being lightweight, insulating and energy-saving. In this study, alkali-treated abaca fiber-reinforced geopolymer composites foamed with H2O2 were developed using fly ash as the geopolymer precursor. The effects of abaca fiber loading, foaming agent dosage, and curing temperature on mechanical strength were evaluated using Box-Behken design of experiment with three points replicated. Volumetric weight of samples ranged from 1966 kg/m3 to 2249 kg/m3. Measured compressive strength and flexural ranged from 19.56 MPa to 36.84 MPa, and 2.41 MPa to 6.25 MPa, respectively. Results suggest enhancement of compressive strength by abaca reinforcement and elevated temperature curing. Results, however, indicate a strong interaction between curing temperature and foaming agent dosage, which observably caused the composite’s compressive strength to decline when simultaneously set at high levels. Foaming agent dosage was the only factor detected to significantly affect flexural strength.

scholarly journals Long-Term Properties of Different Fiber Reinforcement Effect on Fly Ash-Based Geopolymer Composite

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 760
Author(s):  
Rihards Gailitis ◽  
Andina Sprince ◽  
Tomass Kozlovskis ◽  
Liga Radina ◽  
Leonids Pakrastins ◽  
...  
Keyword(s):  
Fly Ash ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Fiber Reinforcement ◽  
Polypropylene Fibers ◽  
Fiber Reinforced ◽  
Waste Products ◽  
Geopolymer Composites ◽  
Creep Strains

Geopolymer composites have been around only for 40 years. Nowadays, they are used in buildings and infrastructures of various kinds. A geopolymer’s main benefit is that it is a green material that is partially made by utilizing waste products. The carbon footprint from geopolymer matrix manufacturing is at least two times less than Portland cement manufacturing. Due to the nature of the geopolymer manufacturing process, there is a high risk of shrinkage that could develop unwanted micro-cracks that could reduce strength and create higher creep strains. Because of this concern, a common strategy to reduce long-term strains of the material, such as shrinkage and creep, is to add fiber reinforcement that would constrain crack development in the material. This article aims to determine how various kinds and amounts of different fiber reinforcement affect fly ash-based geopolymer composites’ creep strains in compression. Specimen mixes were produced with 1% steel fibers, 1% polypropylene fibers, 5% polypropylene fibers, and without fibers (plain geopolymer). For creep and shrinkage testing, cylindrical specimens Ø46 × 190 mm were used. The highest creep resistance was observed in 5% polypropylene fiber specimens, followed by 1% polypropylene fiber, plain, and 1% steel fiber specimens. The highest compressive strength was observed in 1% polypropylene fiber specimens, followed by plain specimens, 1% steel fiber specimens, and 5% polypropylene fiber-reinforced specimens. The only fiber-reinforced geopolymer mix with improved long-term properties was observed with 1% polypropylene fiber inclusion, whereas other fiber-introduced mixes showed significant decreases in long-term properties. The geopolymer composite mix with 1% polypropylene fiber reinforcement showed a reduction in creep strains of 31% compared to the plain geopolymer composite.

On an Original Approach to Model Hemp Fibers Reinforced Thermoplastics

2014 ◽  
Vol 875-877 ◽  
pp. 801-806
Author(s):  
Florian Gehring ◽  
Vanessa Bouchart ◽  
Florence Dinzart ◽  
Pierre Chevrier
Keyword(s):  
Behavior Modeling ◽  
Matrix Cracking ◽  
Thermoplastic Composites ◽  
Experimental Investigations ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
The Matrix ◽  
Reinforced Thermoplastics ◽  
Modeling Strategy ◽  
Original Approach

This paper is devoted to present an approach to model behavior of hemp fibers reinforced thermoplastic composites. Experimental investigations using common testing methods have shown that major physical dissipative phenomena which explained the behavior of polypropylene/ hemp fibers (PP/Hemp) composites took place in the matrix. Moreover these dissipative mechanisms are mainly due to matrix cracking. The behavior modeling of PP/hemp fiber composites is obtained by a two-step modeling strategy. A real based microstructure is automatic generated by own made algorithms according to the observed microstructure by X-ray tomography and constitutive behavior of the matrix is obtained using the micromechanics formalism and is implemented by a FORTRAN routine in ABAQUS® software. This approach seems to have the potential to describe behavior of such composites (PP/Hemp).

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