scholarly journals Strength and Damping Properties of Cementitious Composites Incorporating Original and Alkali Treated Flax Fibers

2019 ◽  
Vol 9 (10) ◽  
pp. 2002
Author(s):  
Pengfei Lai ◽  
Xudong Zhi ◽  
Shizhao Shen ◽  
Zheng Wang ◽  
Ping Yu
Keyword(s):  
Alkali Treatment ◽  
Mechanical Analysis ◽  
Flax Fiber ◽  
Cementitious Composites ◽  
Damping Properties ◽  
Structural Modifications ◽  
Flax Fibers ◽  
Damping Effect ◽  
Reinforced Cement ◽  
Flexural Tests

This experimental investigation focused on the mechanical and damping properties of raw and alkali treated flax fibers reinforced cementitious composites. The objective of this study was to research the influence of flax fiber for the damping properties of cementitious composites. The mechanical strengths were obtained using compressive and flexural tests and damping properties were measured using a dynamic mechanical analysis. Structural modifications to the treated flax fibers were analyzed using scanning electronic microscopy and mercury intrusion porosimetry. Results showed that cement compressive strength was decreased, and flexural strength was increased by the addition of untreated flax fibers. Alkali treatment improved the mechanical strength of flax reinforced cement. The addition of flax fibers improved cement damping properties, and the damping effect of untreated flax fibers was greater than that of alkali treated fibers. The loss tangent of the cementitious composites reinforced with raw and alkali treated flax fibers at an amount of 1 wt % of cement was improved by 45.83% and 37.5% at 20 Hz, respectively. The damping properties of flax fiber was attributed to friction between elementary fibers and between adjacent fiber cell walls and slipping between the fiber and matrix. Callouses, pectin, and lignocellulose in untreated flax fiber contributed to damping and their removal by alkali treatment was the main reason why untreated flax fibers had a greater damping effect as compared to alkali-modified flax fibers.

Effect of silica fume-enhanced carbon nanotube dispersion on the strength and damping properties of cement composites

2020 ◽  
Vol 10 (9) ◽  
pp. 1412-1422
Author(s):  
Miao Wang ◽  
Pengfei Lai ◽  
Yongzhe Li ◽  
Ping Yu ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Silica Fume ◽  
Mercury Intrusion Porosimetry ◽  
Mechanical Analysis ◽  
Cement Composites ◽  
Damping Properties ◽  
Practical Applications ◽  
Carbon Nanotube Dispersion ◽  
Strength Tests ◽  
Reinforced Cement ◽  
Nanotube Dispersion

Carbon nanotubes (CNTs) tend to agglomerate in cement paste, which impedes the effect of performance reinforcement. This paper applies silica fume as an active factor to enhance the dispersion of CNTs and investigates the influence of silica fume on the strength and damping properties of CNT-reinforced cement composites. Mechanical strength tests and dynamic mechanical analysis on specimens with different contents of CNTs (0%, 0.1% and 0.2%) and silica fume (0%, 5%, 10% and 15%) are conducted. The microstructure is characterized by Scanning Electron Microscopy (SEM), and the pore size distribution is measured by Mercury Intrusion Porosimetry (MIP). Due to the CNT dispersion enhancement, both the number of gel pores and the size of microcapillary pores are reduced. The incorporation of silica fume also facilitates the interfacial friction between CNTs and cement hydration products and promotes heat generation, when reciprocating loads are applied. The result indicates that the mixture proportion of CNTs and silica fume strongly influences the extent of the dispersion enhancement, which is optimized at 0.1% and 5%, respectively. Excessive addition of either CNTs or silica fume will hinder CNT dispersion and subsequently reduce the strength and damping properties of the material, which should be avoided in practical applications.

Influence of alkali treatment on flax fiber for use as reinforcements in polylactide stereocomplex composites

2015 ◽  
Vol 55 (11) ◽  
pp. 2553-2558 ◽  
Author(s):  
Huihui Zhang ◽  
Ruihao Ming ◽  
Gesheng Yang ◽  
Yuzeng Li ◽  
Qiao Li ◽  
...  
Keyword(s):  
Alkali Treatment ◽  
Flax Fiber

A strengthening approach for damping property and shape memory property of acrylic rubber/polylactide blends

2018 ◽  
Vol 51 (7-8) ◽  
pp. 626-643
Author(s):  
Chengliang Li ◽  
Xingxing Ji ◽  
Yang Lyu ◽  
Xinyan Shi
Keyword(s):  
Shape Memory ◽  
Loss Factor ◽  
Phenol Formaldehyde ◽  
Mechanical Analysis ◽  
Damping Properties ◽  
Shape Memory Property ◽  
Memory Property ◽  
Damping Material ◽  
Shape Memory Properties ◽  
Shape Memory Effects

In this work, a damping material was successfully prepared by blending acrylic rubber (ACM) and polylactide (PLA) with sulfur and soap salt as the curing agents. A phenol-formaldehyde (PF) resin was used as a modifier. The effects of PF on the mechanical properties, damping properties, compatibility and shape memory properties of the blends were studied. The compatibility and damping properties were characterized by dynamic mechanical analysis, Fourier transform infrared spectroscope and microstructure analysis. The shape memory properties were examined by thermal mechanical analyser. The results revealed that the tensile strength of the blends was decreased and the toughness was increased with the increase of PF loadings. The introduction of PF improved the compatibility between PLA and ACM, which was deduced from the fact that the glass transition temperature of ACM was increased and the two loss factor peaks became closer. It was also found that the loss factor peak became higher and the effective damping temperature range became wider due to the formation of hydrogen bonding, implying that the damping properties of ACM/PLA blends were significantly improved. The ACM/PLA blends exhibited good dual-shape memory effect and its shape recovery ratio was increased by introduction of PF and raising the trigger temperature. The blends also exhibited good triple-shape memory property, which was dramatically improved by the introduction of PF. The mechanisms for the enhanced shape memory effects were then analysed.

scholarly journals THE INFLUENCE OF SEVERAL TYPES OF RESINS ON THE DYNAMIC MECHANICAL PROPERTIES OF POLYMER MIXTURE BASED ON BUTYL RUBBER

2020 ◽  
Vol 3 (2) ◽  
pp. 36-45 ◽  
Author(s):  
O. Tarasova ◽  
Yu. Yurkin ◽  
A. Toroschin
Keyword(s):  
Phenol Formaldehyde ◽  
Dynamic Properties ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Strength Properties ◽  
Butyl Rubber ◽  
Polymer Materials ◽  
Polymer Mixture ◽  
Damping Properties ◽  
Dynamic Mechanical

this work is devoted to the problem of developing vibration-damping polymer materials with high damping properties in a wide temperature range. The study of the effect of modifying additives on the strength, damping, adhesive and cohesive properties of a butyl rubber composite is the aim of this work. The task is to identify the actual temperature, frequency, dynamic and mechanical characteristics of a composite material based on butyl rubber depending on the type and concentration of resins. The key methods for studying this problem is the dynamic mechanical analysis method, aimed at obtaining information about changes in the dynamic properties of polymer materials (bond strength with metal when peeling samples of composites, determining the flow resistance of samples, determining the migration of plasticizer). Due to the established experimental dependences, it was found that the addition of resins (3% by weight) in the composition based on butyl rubber leads to an increase in the damping properties of composite materials, and an increase to (4.25% by weight) leads to their decrease. It was established that the obtained filled mixtures with a high damping peak and good adhesive and strength properties are mixtures with the addition of alkyl phenol-formaldehyde resins.

Damping properties of Li5La3Ta2O12 ceramic particulates reinforced cement composites

2010 ◽  
Vol 528 (2) ◽  
pp. 780-783 ◽  
Author(s):  
Z.P. Kan ◽  
C. Li ◽  
X.P. Wang ◽  
H. Lu ◽  
Q.F. Fang
Keyword(s):  
Cement Composites ◽  
Damping Properties ◽  
Reinforced Cement

scholarly journals Tensile Behavior and Diffusion of Moisture through Flax Fibers by Desorption Method

2019 ◽  
Vol 11 (13) ◽  
pp. 3558 ◽  
Author(s):  
Swarda S. Radkar ◽  
Ali Amiri ◽  
Chad A. Ulven
Keyword(s):  
Diffusion Coefficients ◽  
Natural Fibers ◽  
Woven Fabrics ◽  
Tensile Behavior ◽  
Flax Fiber ◽  
Additional Absorption ◽  
Flax Fibers ◽  
Diffusion Rates ◽  
Desorption Method ◽  
And Diffusion

There has been a substantial increase in the usage of natural fibers and biodegradable polymers in composite materials due to the recent focus on sustainability of materials. Flax fibers have exhibited higher mechanical properties compared to most other natural fibers available. However, one of the major challenges faced in the use of flax fiber is its hydrophilicity. In this study, the tensile behavior of flax fiber tows removed from commercially available woven fabrics were investigated at different moisture levels. The breaking tenacity of fiber tows was shown to increase with an increase in moisture content of up to 25%. After this point, additional absorption of moisture resulted in a decrease of fiber tenacity. In addition, the diffusion process through flax fiber mat with different areal densities was investigated and the diffusion coefficients were determined using the desorption curves. Diffusion rates were not found to significantly change with varying areal densities of 200 to 400 gsm, but were significantly different when exposed to temperatures of 55 °C versus 80 °C.

Revaluation of Australian palm residues in polypropylene composites: Statistical influence of fiber treatment

2020 ◽  
pp. 002199832096053 ◽  
Author(s):  
Noelle C Zanini ◽  
Rennan FS Barbosa ◽  
Alana G de Souza ◽  
Derval S Rosa ◽  
Daniella R Mulinari
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Mechanical Performance ◽  
Alkali Treatment ◽  
Mechanical Analysis ◽  
Melt Mixing ◽  
Polypropylene Composites ◽  
Matrix Interactions ◽  
Fiber Treatment ◽  
Fiber Matrix

Australian palm residues are generated by palm heart industry in large quantities and are considered an underused material with a composition rich in lignocellulosic structures. This residue is generally utilized as briquettes for energy or sheep feed; however, few works investigate this residue as composite fillers. This work aimed to revalue Australian palm residues (PR) by preparing polypropylene composites through melt mixing, using different fiber contents (0, 5, 10, 20, and 30 wt%), and evaluate the statistical influence of fibers (residues) alkali treatment (MPR) in composites mechanical properties. PR and MPR were evaluated by FTIR, XRD, SEM, TGA, and composites were assessed using thermal and mechanical analysis, in which ANOVA statistical analysis was applied. The residues addition increased the mechanical properties and their treatment enhanced the stiffness of the composites compared to pristine PP. However, ANOVA demonstrated that at low residues contents, surface treatment does not increase fiber-matrix interactions effectively, then tensile properties were statistically similar to PP. Considering tensile properties, 20% MPR showed statistically distinct properties, with significative enhancements; no filler contents dependence was verified. Flexural properties were more sensitive to residue loading, and composites with 30% PR and MPR presented superior mechanical performance. This difference is associated with a higher sensitivity of tensile stress towards fiber-matrix interactions, which was improved with fiber treatment. Also, the residues content and treatment influenced the composites' thermal stability, with better results for PP-MPR. Results indicate that palm residue is an excellent filler for improving composites' thermal and mechanical properties, with a greener character.

scholarly journals Nanocelluloses: Natural-Based Materials for Fiber-Reinforced Cement Composites. A Critical Review

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 518 ◽  
Author(s):  
Ana Balea ◽  
Elena Fuente ◽  
Angeles Blanco ◽  
Carlos Negro
Keyword(s):  
Raw Material ◽  
Modulus Of Rupture ◽  
Cement Matrix ◽  
Future Research ◽  
Cementitious Composites ◽  
Natural Material ◽  
Cement Composites ◽  
Fiber Reinforced ◽  
Industrial Sectors ◽  
Reinforced Cement

Nanocelluloses (NCs) are bio-based nano-structurated products that open up new solutions for natural material sciences. Although a high number of papers have described their production, properties, and potential applications in multiple industrial sectors, no review to date has focused on their possible use in cementitious composites, which is the aim of this review. It describes how they could be applied in the manufacturing process as a raw material or an additive. NCs improve mechanical properties (internal bonding strength, modulus of elasticity (MOE), and modulus of rupture (MOR)), alter the rheology of the cement paste, and affect the physical properties of cements/cementitious composites. Additionally, the interactions between NCs and the other components of the fiber cement matrix are analyzed. The final result depends on many factors, such as the NC type, the dosage addition mode, the dispersion, the matrix type, and the curing process. However, all of these factors have not been studied in full so far. This review has also identified a number of unexplored areas of great potential for future research in relation to NC applications for fiber-reinforced cement composites, which will include their use as a surface treatment agent, an anionic flocculant, or an additive for wastewater treatment. Although NCs remain expensive, the market perspective is very promising.

Mechanical Performances of Green Engineered Cementitious Composites Incorporating Various Types of Sand

2019 ◽  
Vol 821 ◽  
pp. 512-517
Author(s):  
Siong Wee Lee ◽  
Chai Lian Oh ◽  
Mohd Raizamzamani Md Zain ◽  
Norrul Azmi Yahya ◽  
Azerai Ali Rahman
Keyword(s):  
Compressive Strength ◽  
Recycled Concrete ◽  
Cementitious Composites ◽  
Flexural Stress ◽  
Engineered Cementitious Composites ◽  
River Sand ◽  
Granulated Blast Furnace Slag ◽  
In Series ◽  
Mechanical Performances ◽  
Flexural Tests

This paper evaluates the mechanical performances of green engineered cementitious composites (ECC) by means of compressive strength and flexural behaviour. Green ECC made of cement, ground granulated blast-furnace slag (GGBS), river sand or recycled concrete fine (RCF), polypropylene (PP) fiber, water and superplasticizer (SP) was employed in this study. Compression test result implies that green ECC incorporating either sieved river sand or sieved RCF (below 600 μm) in series G60 and G70 exhibited greater compressive strength compared with green ECC with unsieved river sand. In series G80, compressive strength of green ECC was not affected by RCF content. Flexural stress-mid deflection curves demonstrated that all green ECC specimens performed more ductile compared to normal concrete as they undergone large deformation capacity after the first cracking strength. Both compression and flexural tests suggested that mixture G80SRCF0.4 containing large amount of sieved RCF and least amount of cement is the best green ECC mixture in this study.

Effect of mercerization of flax fibers on wheat flour/flax fiber biocomposite with respect to thermal and tensile properties

2008 ◽  
Vol 15 (7-9) ◽  
pp. 759-770 ◽  
Author(s):  
Preetha Gopalakrishnan ◽  
Redouan Saiah ◽  
Richard Gattin ◽  
Jean Marc Saiter
Keyword(s):  
Tensile Properties ◽  
Wheat Flour ◽  
Flax Fiber ◽  
Flax Fibers
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