Effect of carbon nanotube on physical and mechanical properties of natural fiber/glass fiber/cement composites

2015 ◽  
Vol 26 (1) ◽  
pp. 247-251 ◽  
Author(s):  
Hamed Younesi Kordkheili ◽  
Shokouh Etedali Shehni ◽  
Ghorban Niyatzade
Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 268
Author(s):  
Jitong Zhao ◽  
Huawei Tong ◽  
Yi Shan ◽  
Jie Yuan ◽  
Qiuwang Peng ◽  
...  

Microbial-induced calcite precipitation (MICP) has been a promising method to improve geotechnical engineering properties through the precipitation of calcium carbonate (CaCO3) on the contact and surface of soil particles in recent years. In the present experiment, water absorption and unconfined compressive strength (UCS) tests were carried out to investigate the effects of three different fiber types (glass fiber, polyester fiber, and hemp fiber) on the physical and mechanical properties of MICP-treated calcareous sand. The fibers used were at 0%, 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, 0.35%, and 0.40% relative to the weight of the sand. The results showed that the failure strain and ductility of the samples could be improved by adding fibers. Compared to biocemented sand (BS), the water absorption of these three fiber-reinforced biocemented sands were, respectively, decreased by 11.60%, 21.18%, and 7.29%. UCS was, respectively, increased by 24.20%, 60.76%, and 6.40%. Polyester fiber produced the best effect, followed by glass fiber and hemp fiber. The optimum contents of glass fiber and polyester fiber were 0.20% and 0.25%, respectively. The optimum content of hemp fiber was within the range of 0.20–0.25%. Light-emitting diode (LED) microscope and scanning electron microscope (SEM) images lead to the conclusion that only a little calcite precipitation had occurred around the hemp fiber, leading to a poor bonding effect compared to the glass and polyester fibers. It was therefore suggested that polyester fiber should be used to improve the properties of biocemented sand.


2021 ◽  
pp. 073168442110140
Author(s):  
Hossein Ramezani-Dana ◽  
Moussa Gomina ◽  
Joël Bréard ◽  
Gilles Orange

In this work, we examine the relationships between the microstructure and the mechanical properties of glass fiber–reinforced polyamide 6,6 composite materials ( V f = 54%). These materials made by thermocompression incorporate different grades of high fluidity polyamide-based polymers and two types of quasi-UD glass fiber reinforcement. One is a classic commercial fabric, while the other specially designed and manufactured incorporates weaker tex glass yarns (the spacer) to increase the planar permeability of the preform. The effects of the viscosity of the polymers and their composition on the wettability of the reinforcements were analyzed by scanning electron microscopy observations of the microstructure. The respective influences of the polymers and the spacer on the mechanical performance were determined by uniaxial tensile and compression tests in the directions parallel and transverse to the warp yarns. Not only does the spacer enhance permeability but it also improves physical and mechanical properties: tensile longitudinal Young’s modulus increased from 38.2 GPa to 42.9 GPa (13% growth), tensile strength increased from 618.9 MPa to 697 MPa (3% growth), and decrease in ultimate strain from 1.8% to 1.7% (5% reduction). The correlation of these results with the damage observed post mortem confirms those acquired from analyses of the microstructure of composites and the rheological behaviors of polymers.


2021 ◽  
pp. 073168442110176
Author(s):  
Oluwole I Oladele ◽  
Baraka A Makinde-Isola ◽  
Adeolu A Adediran ◽  
Oluwaseun T Ayanleye ◽  
Samuel A Taiwo

The demand for durable and sustainable eco-friendly materials in recent times has caused many researchers to consider the use of plant fibers in composite development. In this research, the suitability of treated pawpaw fiber as a substitute for glass fiber was considered. The pawpaw fiber was extracted from the plant stem by dew retting and treated before been incorporated into the epoxy matrix. Two distinct fiber structures in linear and network forms were identified, separated, and used for the development of the composites. The composites were produced by incorporating a fixed amount of pawpaw fiber with a varied amount of glass fiber within 3–15 wt% in epoxy-based polymer matrix after which mechanical and biodegradation tests were carried out on the developed samples. Fractured surface morphology was also observed using a scanning electron microscope. The results revealed that the fiber structures influence the properties of the material. While mechanical properties were mostly enhanced by treated linear structure pawpaw fiber, biodegradation was highly promoted by treated network structure pawpaw fiber. Tensile (except for strain), hardness, and flexural properties were enhanced by the linear-structured treated pawpaw fiber, while biodegradability, impact, and tensile strain were improved by the network-structured treated pawpaw fiber compared to the control sample.


2010 ◽  
Vol 442 ◽  
pp. 52-58
Author(s):  
M.A. Bashir ◽  
H. Ahmad ◽  
R. Ahmed ◽  
R.A. Alvi ◽  
Mohammad Bilal Khan

Ablative composites are heat shielding, protective materials that are being used in aerospace industry to protect inner hardware and sensitive devices. The aero dynamic vehicles have to face high stresses, ultra high temperature and adverse conditions of air friction. It is required to develop the materials with light weight and high modulus. EPDM, being heat and ozone attack resistant is the best candidate for the preparation of ablative composites by introducing different heat sinks such as silica, glass fiber, carbon fiber, asbestos, carbon and their combinations have been studied in this work. The prepared materials were tested and it was found that visco elastic behavior of the composites affected by the addition of reinforcing filler (carbon, silica), semi-reinforcing filler (carbon fiber, glass fiber) and non-reinforcing filler (asbestos powder). Mechanical properties tested at different rates, revealed the improvement in tensile strength and % elongation in case of reinforcing and semi-reinforcing fillers but showed adverse effect in case of non-reinforcing fillers. Rheological investigations of these novel composites shows that moony viscosity of the materials containing glass fiber, carbon fiber, silica decreases in the order glass fiber > carbon fiber > silica.


Materials ◽  
2017 ◽  
Vol 10 (11) ◽  
pp. 1252 ◽  
Author(s):  
Bryn Crawford ◽  
Sepideh Pakpour ◽  
Negin Kazemian ◽  
John Klironomos ◽  
Karen Stoeffler ◽  
...  

Author(s):  
Viola Hospodarova ◽  
Nadezda Stevulova ◽  
Vojtech Vaclavik ◽  
Tomas Dvorsky ◽  
Jaroslav Briancin

Nowadays, construction sector is focusing in developing sustainable, green and eco-friendly building materials. Natural fibre is growingly being used in composite materials. This paper provides utilization of cellulose fibres as reinforcing agent into cement composites/plasters. Provided cellulosic fibres coming from various sources as bleached wood pulp and recycled waste paper fibres. Differences between cellulosic fibres are given by their physical characterization, chemical composition and SEM micrographs. Physical and mechanical properties of fibre-cement composites with fibre contents 0.2; 0.3and 0.5% by weight of filler and binder were investigated. Reference sample without fibres was also produced. The aim of this work is to investigate the effects of cellulose fibres on the final properties (density, water absorbability, coefficient of thermal conductivity and compressive strength) of the fibrecement plasters after 28 days of hardening. Testing of plasters with varying amount of cellulose fibres (0.2, 0.3 and 0.5 wt. %) has shown that the resulting physical and mechanical properties depend on the amount, the nature and structure of the used fibres. Linear dependences of compressive strength and thermal conductivity on density for plasters with cellulosic fibres adding were observed.


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