scholarly journals Physical and Chemical Modifications of Plant Fibres for Reinforcement in Cementitious Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
R. Ahmad ◽  
R. Hamid ◽  
S. A. Osman
Keyword(s):  
Mechanical Properties ◽  
Interfacial Adhesion ◽  
Moisture Absorption ◽  
Surface Modifications ◽  
Future Research ◽  
Cementitious Composites ◽  
Chemical Surface ◽  
Plant Fibre ◽  
Physical And Chemical ◽  
Fibre Matrix

This paper highlights the physical and chemical surface modifications of plant fibre (PF) for attaining suitable properties as reinforcements in cementitious composites. Untreated PF faces insufficient adhesion between the fibres and matrix due to high levels of moisture absorption and poor wettability. These conditions accelerate degradation of the fibre in the composite. It is also essential to reduce the risk of hydrophilic PF conditions with surface modification, to enhance the mechanical properties of the fibres. Fibres that undergo chemical and physical modifications had been proven to exhibit improved fibre-matrix interfacial adhesion in the composite and contribute to better composite mechanical properties. This paper also gives some recommendations for future research on chemical and physical modifications of PF.

scholarly journals Effect of Fibre Types on the Tensile Behaviour of Engineered Cementitious Composites

2021 ◽  
Vol 8 ◽  
Author(s):  
Mingzhang Lan ◽  
Jian Zhou ◽  
Mingfeng Xu
Keyword(s):  
Mechanical Properties ◽  
Experimental Result ◽  
Tensile Behaviour ◽  
Cementitious Composites ◽  
Matrix Interface ◽  
Cementitious Composite ◽  
Engineered Cementitious Composite ◽  
Fibre Bridging ◽  
The Difference ◽  
Fibre Matrix

Engineered cementitious composite (ECC) is a group of ultra-ductile fibre-reinforced cementitious composites, characterised by high ductility and moderate content of short discontinuous fibre. The unique tensile strain-hardening behaviour of ECC results from a deliberate design based on the understanding of micromechanics between fibre, matrix, and fibre–matrix interface. To investigate the effect of fibre properties on the tensile behaviour of ECCs is, therefore, the key to understanding the composite mechanical behaviour of ECCs. This paper presents a study on the fibre-bridging behaviour and composite mechanical properties of ECCs with three types of fibres, including oil-coated polyvinyl alcohol (PVA) fibre, untreated PVA fibre, and polypropylene (PP) fibre. The experimental result reveals that various fibres with different properties result in difference in the fibre-bridging behaviour and composite mechanical properties of ECCs. The difference in the composite mechanical properties of ECCs with different fibres was interpreted by analysing the fibre-bridging behaviour.

Isocyanate Modification of Wood Fiber in Enhancing the Performance of its Composites with High Density Polyethylene

2012 ◽  
Vol 3 (2) ◽  
pp. 43-60 ◽  
Author(s):  
Fereshteh Arjmand ◽  
Mohammad Barmar ◽  
Mehdi Barikani
Keyword(s):  
Mechanical Properties ◽  
Interfacial Adhesion ◽  
Moisture Absorption ◽  
Wood Fiber ◽  
Cetyl Alcohol ◽  
Toluene Diisocyanate ◽  
Coupling Agents ◽  
Ftir Analysis ◽  
Moisture Uptake ◽  
Chemical Treatments

This study is focused on the modification of wood fiber by using a reactive diisocyanate (toluene diisocyanate, TDI) linker to couple wood fiber with cetyl alcohol and the investigation of its effects on mechanical properties of wood fiber–HDPE composites. The reaction of TDI with wood fiber and then cetyl alcohol resulted in the formation of new urethane bonds assessed by FTIR analysis. Therefore, TDI ended cetyl alcohol was used as a coupling agent in the preparation of wood fiber/ HDPE composite. The outcomes showed that the addition of such coupling agents resulted in greater reinforcement of composites, as indicated by the improvement in mechanical properties. Tensile strength of prepared composites increased by almost 64%, whereas 47% increase in flexural strength and 113% increase in impact properties was observed. However, the moisture absorption of the composites decreased by about 43%. All chemically treated composites showed lower moisture uptake than the untreated composites. This may be due to chemical treatment of wood fiber which reduces its hydrophilicity. These chemical treatments promote interfacial adhesion of fiber and HDPE matrix. Furthermore, scanning electron microscopy (SEM) revealed the improved morphology of the fractured surfaces of composites.

scholarly journals Effect of Macro-, Micro- and Nano-Calcium Carbonate on Properties of Cementitious Composites—A Review

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 781 ◽  
Author(s):  
Mingli Cao ◽  
Xing Ming ◽  
Kaiyu He ◽  
Li Li ◽  
Shirley Shen
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Dilution Effect ◽  
Hydration Process ◽  
Cementitious Composites ◽  
Inert Filler ◽  
Nucleation Effect ◽  
Chemical Effects ◽  
Physical Effects ◽  
Physical And Chemical

Calcium carbonate is wildly used in cementitious composites at different scales and can affect the properties of cementitious composites through physical effects (such as the filler effect, dilution effect and nucleation effect) and chemical effects. The effects of macro (>1 mm)-, micro (1 μm–1 mm)- and nano (<1 μm)-sizes of calcium carbonate on the hydration process, workability, mechanical properties and durability are reviewed. Macro-calcium carbonate mainly acts as an inert filler and can be involved in building the skeletons of hardened cementitious composites to provide part of the strength. Micro-calcium carbonate not only fills the voids between cement grains, but also accelerates the hydration process and affects the workability, mechanical properties and durability through the dilution, nucleation and even chemical effects. Nano-calcium carbonate also has both physical and chemical effects on the properties of cementitious composites, and these effects behave even more effectively than those of micro-calcium carbonate. However, agglomeration of nano-calcium carbonate reduces its enhancement effects remarkably.

An experimental study on the interdependence of mercerization, moisture absorption and mechanical properties of sustainable Phoenix sp. fibre-reinforced epoxy composites

2018 ◽  
Vol 49 (9) ◽  
pp. 1233-1251 ◽  
Author(s):  
G Rajeshkumar
Keyword(s):  
Mechanical Properties ◽  
Moisture Absorption ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Length ◽  
Fibre Volume ◽  
Epoxy Composites ◽  
Compression Moulding ◽  
Fibre Matrix ◽  
Fibre Reinforced Composites

This paper represents the first effort aimed to study the interdependence of mercerization, moisture absorption and mechanical properties of sustainable Phoenix sp. fibre-reinforced epoxy composites fabricated by compression moulding technique. The investigation was carried out by varying the fibre length (10, 20 and 30 mm), fibre volume fraction (10%, 20%, 30%, 40% and 50%), concentration of sodium hydroxide for fibre treatment (5%, 10% and 15%) and immersion temperature (10℃, 30℃ and 60℃). The fibre–matrix interface and failure mechanism was studied by using scanning electron microscopy. The results revealed that the moisture absorption rate increased with the increase in fibre length, fibre volume fraction and immersion temperature result in loss of tensile and flexural properties. The moisture absorbed samples shows 15% and 7% drop in tensile and flexural strength, respectively. However, this loss was less in mercerized fibre-reinforced composites.

scholarly journals Effect of Mercerization/Alkali Surface Treatment of Natural Fibres and Their Utilization in Polymer Composites: Mechanical and Morphological Studies

2021 ◽  
Vol 5 (7) ◽  
pp. 175
Author(s):  
Deepak Verma ◽  
Kheng Lim Goh
Keyword(s):  
Mechanical Properties ◽  
Surface Treatment ◽  
Polymer Composites ◽  
Soil Pollution ◽  
Polymer Composite ◽  
Interfacial Adhesion ◽  
Moisture Absorption ◽  
Treatment Method ◽  
Natural Fibres ◽  
Morphological Studies

Environmental pollution, such as air, water, and soil pollution, has become the most serious issue. Soil pollution is a major concern as it generally affects the lands and makes them non-fertile. The main cause of soil pollution is agro-waste. It may be possible to mitigate the agro-waste pollution by re-utilizing this agro-waste, namely natural fibres (NFs), by blending into polymer-based material to reinforce the polymer composite. However, there are pros and cons to this approach. Consequently, the polymer composite materials fabricated using NFs are inferior to those polymer composites that are reinforced by, e.g., carbon or glass fibres from the mechanical properties’ perspectives. The limitations of utilizing natural fibres in polymer matrix are their high moisture absorption, resulting in high swelling rate and degradation, inferior resistance to fire and chemical, and inferior mechanical properties. In particular, the NF polymer composites exhibit inferior interfacial adhesion between the fibre and the matrix, which, if improved, ultimately overcome all the listed limitations and improve the mechanical properties of the developed composites. To improve the interfacial adhesion leading to the enhancement of the mechanical properties, optimum chemical treatment such as Alkalization/Mercerization of the fibres have been explored. This article discusses the Mercerization/Alkali surface treatment method for NFs and its effects on the fibres regarding the Mercerization/Alkali surface treatment method for NFs and its effect on the fibres regarding their utilization in the polymer composites, the morphological features, and mechanical properties of composites.

scholarly journals Ultrasound-Assisted Surface Modifications on Ceramic Reinforcement for Lead-Free Composite Solders : Short Review

2021 ◽  
Vol 2080 (1) ◽  
pp. 012025
Author(s):  
Wai Keong Leong ◽  
Ahmad Azmin Mohamad ◽  
Muhammad Firdaus Nazeri
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Positive Impact ◽  
Solder Matrix ◽  
Surface Modifications ◽  
Short Review ◽  
Lead Free ◽  
Future Research ◽  
Ultrasound Assisted ◽  
Ceramic Reinforcement

Abstract The purpose of this paper is to review and examine the effect of ultrasound-assisted surface modifications of ceramic reinforcements on the properties of lead-free solders. The discussion will highlight the fundamental understanding, main parameters, configurations, and recent surface-modified ceramic reinforced composite lead-free solder developments. The review also identified and summarized the advantages, current trends, and significant findings in this field. The ultrasound-assisted surface modification was found to provide a crucial improvement on the wettability properties of molten solders as the matrix phase on the ceramic reinforcement. Further, the excellent distribution of ceramic reinforcement in solder matrix was also seen after the surface modification process. This has led to significant improvements in mechanical properties such as hardness and strength. The pinning of dislocation movement was seen as the reason for improving the mechanical properties. This positive impact in enhancing the ceramic reinforcement-solder interfacial reaction allows more explicit future research directions and opportunities for composite solder applications.

An Energy-Based interpretation of Interfacial Adhesion from Single Fibre Composite Fragmentation Testing

1993 ◽  
Vol 2 (5) ◽  
pp. 096369359300200 ◽  
Author(s):  
H.D. Wagner ◽  
S. Ling
Keyword(s):  
Interfacial Adhesion ◽  
Mechanical Characteristics ◽  
Interfacial Shear Strength ◽  
Fibre Composite ◽  
Stress Transfer ◽  
Single Fibre ◽  
Transfer Length ◽  
Fragmentation Test ◽  
Energy Balance Approach ◽  
Fibre Matrix

An energy balance approach is proposed for the single fibre composite (or fragmentation) test, by which the degree of fibre-matrix bonding is quantified by means of the interfacial energy, rather than the interfacial shear strength, as a function of the fibre geometrical and mechanical characteristics, the stress transfer length, and the debonding length. The validity of the approach is discussed using E-glass fibres embedded in epoxy, both in the dry state and in the presence of hot distilled water.

scholarly journals Effects of Steel Fiber Percentage and Aspect Ratios on Fresh and Harden Properties of Ultra-High Performance Fiber

2021 ◽  
Vol 2 (3) ◽  
pp. 501-515
Author(s):  
Rajib Kumar Biswas ◽  
Farabi Bin Ahmed ◽  
Md. Ehsanul Haque ◽  
Afra Anam Provasha ◽  
Zahid Hasan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Performance ◽  
Steel Fiber ◽  
Setting Time ◽  
Fiber Reinforced Concrete ◽  
Future Research ◽  
Manufacturing Cost ◽  
Aspect Ratios ◽  
High Performance Fiber

Steel fibers and their aspect ratios are important parameters that have significant influence on the mechanical properties of ultrahigh-performance fiber-reinforced concrete (UHPFRC). Steel fiber dosage also significantly contributes to the initial manufacturing cost of UHPFRC. This study presents a comprehensive literature review of the effects of steel fiber percentages and aspect ratios on the setting time, workability, and mechanical properties of UHPFRC. It was evident that (1) an increase in steel fiber dosage and aspect ratio negatively impacted workability, owing to the interlocking between fibers; (2) compressive strength was positively influenced by the steel fiber dosage and aspect ratio; and (3) a faster loading rate significantly improved the mechanical properties. There were also some shortcomings in the measurement method for setting time. Lastly, this research highlights current issues for future research. The findings of the study are useful for practicing engineers to understand the distinctive characteristics of UHPFRC.

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