scholarly journals Investigation of the Potential Use of Curauá Fiber for Reinforcing Mortars

Fibers ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 69
Author(s):  
Afonso R. G. de Azevedo ◽  
Sergey Klyuev ◽  
Markssuel T. Marvila ◽  
Nikolai Vatin ◽  
Nataliya Alfimova ◽  
...  
Keyword(s):  
Water Retention ◽  
Natural Fibers ◽  
Northern Region ◽  
Technological Properties ◽  
Wetting And Drying ◽  
Air Content ◽  
Naoh Solution ◽  
Potential Use ◽  
Reference Mixture ◽  
Curauá Fiber

Curauá is a bromeliad of Amazonian origin, present in some states in the northern region of Brazil and in other countries in South America. Its natural fibers have several technological advantages for application in composite materials. The objective of this research was to investigate the potential of using the fiber of Curauá as a reinforcement element in mortars for wall covering. Mortars were made with a 1:1:6 ratio (cement:lime:sand) in relation to their mass, evaluating the effect of adding 1%, 2% and 3% of Curauá fiber natural and fiber treated in NaOH solution in relation to the mass of cement, compared to the reference mixture (0%). Technological properties such as consistency, water retention and incorporated air content, compressive strength, water absorption and durability in wetting and drying cycles were evaluated. The results showed that the addition of the Curauá fiber causes an improvement in the mechanical properties of mortars, and at levels of addition 3% or more, it causes problems of workability and incorporation of air into the dough, thus, the fiber addition in 2% presented better results for application in coating mortars, in relation a Brazilian norm, even improving the durability of external coatings.

scholarly journals Mechanical Properties of Mortars Reinforced with Amazon Rainforest Natural Fibers

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 155
Author(s):  
Régis Pamponet da Fonseca ◽  
Janaíde Cavalcante Rocha ◽  
Malik Cheriaf
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Natural Fibers ◽  
Construction Materials ◽  
Hot Water ◽  
Amazon Rainforest ◽  
Hot Water Treatment ◽  
Composite Binder ◽  
Naoh Solution ◽  
Reference Samples

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.

scholarly journals Effect of Olive-Pine Bottom Ash on Properties of Geopolymers Based on Metakaolin

2019 ◽  
Author(s):  
Eduardo Bonet-Martínez ◽  
Pedro García-Cobo ◽  
Luis Pérez-Villarejo ◽  
Eulogio Castro ◽  
Dolores Eliche-Quesada
Keyword(s):  
Room Temperature ◽  
Bottom Ash ◽  
Raw Material ◽  
Climatic Chamber ◽  
General Terms ◽  
Saturated Atmosphere ◽  
Naoh Solution ◽  
Alkaline Activator ◽  
Water Saturated ◽  
Potential Use

In this research, the feasibility of using bottom ashes generated by the combustion of biomass (olive pruning and pine pruning) as a source of aluminosilicates (OPBA) has been studied, replacing the metakaolin precursor (MK) in different proportions (0, 25, 50, 75 and 100 wt. % substitution) for the synthesis of geopolymers. As alkaline activator an 8 M NaOH solution and a Na2SiO3 have been used. The geopolymers were cured 24 hours in a climatic chamber at 60 ° C in a water-saturated atmosphere, subsequently demoulded and cured at room temperature for 28 days. The results indicated that the incorporation of OPBA waste, which have 19.7 wt. % of Ca, modifies the characteristics of the products formed after alkaline activation. In general terms, the incorporation of increasing amounts of calcium-rich ashes results in geopolymers with higher bulk density. The compressive strength increases with the addition of up to 50 wt. % of OPBA with respect to the control geopolymers, contributing the composition of the residue to the acquisition of a better behaviour mechanical. The results indicate the potential use of these OPBA waste as raw material to produce unconventional cements with 28-day curing strengths greater than 10 MPa, and thermal conductivities less than 0.35 W/mK.

scholarly journals Influence of Treated Natural Jute Fiber on Flexural Properties of Reinforced Concrete Beams

2018 ◽  
Vol 7 (3.12) ◽  
pp. 148 ◽  
Author(s):  
Bharathi Murugan.R ◽  
Ajit Gayke ◽  
Natarajan C ◽  
Haridharan. M.K ◽  
Murali G ◽  
...  
Keyword(s):  
Low Cost ◽  
Natural Fibers ◽  
Reinforced Concrete Beams ◽  
Jute Fiber ◽  
Tension Zone ◽  
Synthetic Fibers ◽  
Stiffness Characteristic ◽  
Fiber Concrete ◽  
Recent Trends ◽  
Potential Use

India is one of the largest producers of jute, its potential use in many branches of engineering should be developed for the prosperity of the nation. The recent trends in utilizing the natural fibers has increased due to its advantages over synthetic fibers due to low cost, low environment hazard and easy availability. The properties of the fiber is improved by treating the jute fiber with alkali and latex polymer. Since, very few studies been conducted using the treated jute fiber concrete, an experimental work was carried with 0.6% as optimum percentage of treated jute fibers based on the mechanical properties of concrete. The influence of flexural characteristics of concrete was compared with control beams and beams cast with fibers in whole area and also only in tension zone of beam for M20 and M25 concrete grade. The beams with fibers of whole area had better strength, stiffness characteristic than the control beam and the beam with fibers in tension zone only. The initial cracking load was increased by 12.92% and 11.23 % and ultimate load was increased by 6.94% and 7. 20% for the beams cast with fibers in whole area for M20 and M25 grade of concrete, respectively.  

scholarly journals Effect of Granite Residue Incorporation on the Behavior of Mortars

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1449 ◽  
Author(s):  
Afonso Rangel Garcez de Azevedo ◽  
Markssuel Teixeira Marvila ◽  
Laimara da Silva Barroso ◽  
Euzébio Bernabé Zanelato ◽  
Jonas Alexandre ◽  
...  
Keyword(s):  
Water Retention ◽  
Building Materials ◽  
Building Construction ◽  
Squeeze Flow ◽  
Technological Properties ◽  
Rheological Characterization ◽  
Ornamental Stone ◽  
Fresh State ◽  
The World ◽  
Residue Incorporation

Civil construction is one of the most resource-consuming sectors in the world. For this reason, the last years have witnessed the study of reusing industrial residues in building materials. The ornamental stone processing industry has a considerable environmental liability related to residue generation during the cutting stages of granite blocks. The objective of this work is to analyze the viability of incorporating granite residues, up to 100%, to substitute sand in coating mortars for building construction. Mortars without residue, as control, and incorporated with 20, 40, 60, 80, and 100% of granite residue were subjected to consistency tests, incorporated air and water retention together with the rheological characterization using the squeeze-flow and the dropping-ball methods. The results show that mortars with 40% granite residues presented greater plastic deformation, helping their applicability by also presenting improved technological properties in the fresh state.

scholarly journals Effect of Graphene Oxide Coating on Natural Fiber Composite for Multilayered Ballistic Armor

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1356 ◽  
Author(s):  
Ulisses Oliveira Costa ◽  
Lucio Fabio Cassiano Nascimento ◽  
Julianna Magalhães Garcia ◽  
Sergio Neves Monteiro ◽  
Fernanda Santos da Luz ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Natural Fiber ◽  
Fiber Composite ◽  
Natural Fibers ◽  
Oxide Coating ◽  
Synthetic Fibers ◽  
Comparable Performance ◽  
Strong Candidate ◽  
Natural Fiber Composite ◽  
Curauá Fiber

Composites with sustainable natural fibers are currently experiencing remarkably diversified applications, including in engineering industries, owing to their lower cost and density as well as ease in processing. Among the natural fibers, the fiber extracted from the leaves of the Amazonian curaua plant (Ananas erectifolius) is a promising strong candidate to replace synthetic fibers, such as aramid (Kevlar™), in multilayered armor system (MAS) intended for ballistic protection against level III high velocity ammunition. Another remarkable material, the graphene oxide is attracting considerable attention for its properties, especially as coating to improve the interfacial adhesion in polymer composites. Thus, the present work investigates the performance of graphene oxide coated curaua fiber (GOCF) reinforced epoxy composite, as a front ceramic MAS second layer in ballistic test against level III 7.62 mm ammunition. Not only GOCF composite with 30 vol% fibers attended the standard ballistic requirement with 27.4 ± 0.3 mm of indentation comparable performance to Kevlar™ 24 ± 7 mm with same thickness, but also remained intact, which was not the case of non-coated curaua fiber similar composite. Mechanisms of ceramic fragments capture, curaua fibrils separation, curaua fiber pullout, composite delamination, curaua fiber braking, and epoxy matrix rupture were for the first time discussed as a favorable combination in a MAS second layer to effectively dissipate the projectile impact energy.

scholarly journals Effect of Olive-Pine Bottom Ash on Properties of Geopolymers Based on Metakaolin

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 901
Author(s):  
Eduardo Bonet-Martínez ◽  
Pedro García-Cobo ◽  
Luis Pérez-Villarejo ◽  
Eulogio Castro ◽  
Dolores Eliche-Quesada
Keyword(s):  
Room Temperature ◽  
Bottom Ash ◽  
Raw Material ◽  
Climatic Chamber ◽  
General Terms ◽  
Saturated Atmosphere ◽  
Naoh Solution ◽  
Alkaline Activator ◽  
Water Saturated ◽  
Potential Use

In this research, the feasibility of using bottom ashes generated by the combustion of biomass (olive pruning and pine pruning) as a source of aluminosilicates (OPBA) has been studied, replacing the metakaolin precursor (MK) in different proportions (0, 25, 50, 75, and 100 wt.% substitution) for the synthesis of geopolymers. As alkaline activator an 8 M NaOH solution and a Na2SiO3 have been used. The geopolymers were cured 24 h in a climatic chamber at 60 °C in a water-saturated atmosphere, subsequently demoulded and cured at room temperature for 28 days. The results indicated that the incorporation of OPBA waste, which have 19.7 wt.% of Ca, modifies the characteristics of the products formed after alkaline activation. In general terms, the incorporation of increasing amounts of calcium-rich ashes results in geopolymers with higher bulk density. The compressive strength increases with the addition of up to 50 wt.% of OPBA with respect to the control geopolymers, contributing the composition of the residue to the acquisition of better mechanical behavior. The results indicate the potential use of these OPBA waste as raw material to produce unconventional cements with 28-day curing strengths greater than 10 MPa, and thermal conductivities less than 0.35 W/mK.

The Properties of Linear Low Density Polyethylene/Cyperus Odoratus (LLDPE/CY) Blends: Effect of Sodium Hydroxide

2015 ◽  
Vol 815 ◽  
pp. 69-73 ◽  
Author(s):  
Nik Ahmad Faris Nik Abdullah ◽  
Nik Noriman Zulkepli ◽  
Sam Sung Ting ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Sodium Hydroxide ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Natural Fibers ◽  
Biodegradable Plastics ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Naoh Solution

The purpose of this study was to determine the effect of treated Cyperus Odoratus (CY) with sodium hydroxide (NaOH) on the properties of biodegradable plastics made from linear low density polyethylene (LLDPE)/CY blends. Alkali treatments for natural fibers can increased adhesion between the hydrophilic fibers and hydrophobic matric. After CY was treated with 5% NaOH solution, it can be seen that the tensile strength and Young’s modulus of the LLDPE/CY blends significantly increased. Therefore, alkali treatments can be considered in modifying the properties of natural fibers.

Binary packing theory and the physical properties of aggregates

Soil Research ◽  
1978 ◽  
Vol 16 (3) ◽  
pp. 283 ◽  
Author(s):  
KJ Coughlan ◽  
RJ Loch ◽  
WE Fox
Keyword(s):  
Physical Properties ◽  
Water Retention ◽  
Void Ratio ◽  
Wetting And Drying ◽  
Compacted Soil ◽  
Soil Mixing ◽  
Swelling Capacity ◽  
Sand Particles ◽  
Clay Percentage ◽  
Coarse To Fine

The objective of this study was to examine variations in the physical properties of non-compacted soil-sand aggregates in terms of binary packing theory. Two soils were used, a swelling black earth and a krasnozem with low swelling capacity, and aggregates with varying clay percentage were prepared by dispersing the soil, mixing with 100-50 �m sand, and wetting and drying. At lower clay percentages, void ratio with increasing clay was greater than that predicted from theory. This was attributed to clay entering between sand junctions and increasing porosity by expanding the coarse matrix. From water retention and swelling data, the transition from coarse to fine matrix occurs in both soils at about 40 % clay. In the fine particle matrix, variation of void ratio in the krasnozem aggregates was as expected from theory. In the black earth, no significant variation in void ratio occurs at clay percentages > 40%. This was attributed to porosity created around the sand particles owing to differential swelling and shrinkage. Results obtained by other workers are explained in terms of binary packing theory and the concepts developed in this paper.

scholarly journals INFLUENCE OF MINERAL AGGREGATE CONCENTRATION ON THE TECHNOLOGICAL PROPERTIES OF FRESH CONCRETE MIXTURE / MINERALINIŲ UŽPILDŲ KONCENTRACIJOS ĮTAKA ŠVIEŽIO BETONO MIŠINIO TECHNOLOGINĖMS SAVYBĖMS

2013 ◽  
Vol 5 (2) ◽  
pp. 54-60 ◽  
Author(s):  
Albertas Klovas ◽  
Mindaugas Daukšys ◽  
Gintas Brazas
Keyword(s):  
Fine Particles ◽  
Fresh Concrete ◽  
Flow Characteristics ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
Technological Properties ◽  
Sand Fraction ◽  
Mineral Aggregate ◽  
Air Content ◽  
Slump Flow

The main aim of this research was to investigate how the concentration of mineral aggregate influences the technological properties of concrete mixture such as: slump, flow characteristics and air content, as well as the density of concrete mixture. To sum up, 18 concrete mixture compositions were casted. First six compositions were casted in order to establish the dependence between the ratio of fine aggregate (sand fraction: 0/1 and 0/4) and the technological properties of fresh concrete mixture. Another six compositions were casted in order to investigate the link between course aggregate (gravel, fraction 4/16) concentration and the concrete mixture's technological properties. The last six mixtures were casted in order to test how the amount of fine particles (not exceeding 0.25 mm in diameter) influences the concrete mixture's technological properties. Santrauka Pagrindinis šio tyrimo tikslas – nustatyti, kaip mineralinių užpildų koncentracija veikia technologines betono mišinio savybes: slankumą, sklidumą, oro kiekį ir mišinio tankį. Iš viso buvo tirta 18 skirtingų betono mišinio sud≑čių. Pirmosios šešios sudėtys buvo analizuojamos siekiant nustatyti priklausomybę tarp smulkaus užpildo koncentracijos (smėlio frakcijos: 0/1 bei 0/4) ir technologinių betono mišinio savybių. Kitos šešios sudėtys buvo analizuojamos siekiant rasti priklausomybę tarp stambaus užpildo koncentracijos (žvirgždo frakcija 4/16) ir technologinių betono mišinio savybių. Paskutinės šešios betono mišinio sudėtys buvo analizuojamos siekiant nustatyti smulkiųjų dalelių, kurių skersmuo neviršija 0,25 mm, kiekio įtaką technologinėms betono mišinio savybėms.

Characterization of Curaua Fibers by Infrared Spectroscopy

2014 ◽  
Vol 775-776 ◽  
pp. 325-329 ◽  
Author(s):  
Sergio Neves Monteiro ◽  
Frederico Muylaert Margem ◽  
Noan Tonini Simonassi ◽  
Rômulo Leite Loiola ◽  
Michel Picanço Oliveira
Keyword(s):  
Infrared Spectroscopy ◽  
Natural Fibers ◽  
High Strength ◽  
Relevant Information ◽  
Lignocellulosic Fibers ◽  
The Fourier Transform ◽  
Curaua Fibers ◽  
Physical And Chemical ◽  
Curauá Fiber

Natural fibers obtained from plants are being investigated as possible engineering materials with application in polymer composite reinforcement. For instance, the lignocellulosic fibers extracted from the leaves of the curaua plant (Ananas erectifolius) display a reinforcement potential owing to their relatively high strength. However, the curaua fiber has a poor adhesion with the polymeric matrix. In order to understand the curaua fiber interaction with a polymer matrix, the physical and chemical characteristics need to be evaluated. Among these characteristics, the Fourier transform infrared spectroscopy (FTIR) provides relevant information about the functional molecular groups and their possible interaction. Therefore, the objective of the present work was to analyze the FTIR of curaua fibers by means of transmittance spectrum obtained in the FTIR method with a 60o angle. The results showed peaks corresponding to specific molecular interaction that are discussed and compared to other results.

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