scholarly journals Preparation and Mechanical Properties of Graphene Oxide: Cement Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Fakhim Babak ◽  
Hassani Abolfazl ◽  
Rashidi Alimorad ◽  
Ghodousi Parviz

We investigate the performance of graphene oxide (GO) in improving mechanical properties of cement composites. A polycarboxylate superplasticizer was used to improve the dispersion of GO flakes in the cement. The mechanical strength of graphene-cement nanocomposites containing 0.1–2 wt% GO and 0.5 wt% superplasticizer was measured and compared with that of cement prepared without GO. We found that the tensile strength of the cement mortar increased with GO content, reaching 1.5%, a 48% increase in tensile strength. Ultra high-resolution field emission scanning electron microscopy (FE-SEM) used to observe the fracture surface of samples containing 1.5 wt% GO indicated that the nano-GO flakes were well dispersed in the matrix, and no aggregates were observed. FE-SEM observation also revealed good bonding between the GO surfaces and the surrounding cement matrix. In addition, XRD diffraction data showed growth of the calcium silicate hydrates (C-S-H) gels in GO cement mortar compared with the normal cement mortar.

Buildings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 149 ◽  
Author(s):  
Banjo Akinyemi ◽  
Temidayo Omoniyi

This study evaluated the properties of latex modified cement mortars from ordinary paints which were reinforced with treated bamboo fibers from construction waste. Fiber variations of 0, 0.5, 1 and 1.5% at 10% of the weight of cement were utilized. Mechanical properties were determined according to standards; similarly, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to analyze the microstructural and elemental properties of the samples. The experimental results revealed that the addition of 1.5% bamboo fibers and 10% latex solution produced excellent mechanical properties. This was as a result of improved fiber adhesion to the matrix through pre-treatment, coupled with the contributed high strength from the latex paint modified mortars. The micrograph showed that latex precipitated in the voids and on the surface of the bamboo fibers as well as gels of calcium silicate hydrates which contributed to the observed improvement in strength of the tested samples.


2019 ◽  
Vol 9 (11) ◽  
pp. 2178 ◽  
Author(s):  
Jie Fan ◽  
Gengying Li ◽  
Sijie Deng ◽  
Zhongkun Wang

The mechanical properties of cement mortars with 0~2.0% (by mass) polyvinyl alcohol (PVA) were experimentally studied, and the effects of PVA incorporation on the hydration products and microstructure of the cement mortar were determined with differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results show that the rational content of PVA formed evenly dispersed network-like thin films within the cement matrix, and these network-like films can bridge cracks in the cement matrix and improve the mechanical properties of the cement mortar. Over- incorporation of PVA may result in the formation of large piece polymer films that coat the cement particles, delay the hydration of the cement mortar and adversely affect its performance. The mechanical properties of the cement mortar show a significant increase and then decrease with a change in the PVA incorporation. When the PVA content was 0.6% and 1.0%, the mortar had the best compressive and flexural strengths, respectively. The compressive strength of the cement mortar increased by 12.15% for a PVA content of 0.6%, and the flexural strength of the cement mortar increased by 24.83% for a PVA content of 1.0%.


2014 ◽  
Vol 711 ◽  
pp. 158-161
Author(s):  
Xia Zhang ◽  
Cong Ke Wang ◽  
Rui Zhang ◽  
Chuan Wei Du ◽  
Guo Zhong Li

In this article, the influence of the churning technology on the average diameter of xonotlite particle and the micro-structure of xonotlite particle during the hydrothermal synthesis progress of the heat insulating material of xonotlite were researched. The influence of fiber adding process on the strength and density of calcium silicate insulation material was studied. The complexity and the macro mechanical properties of the fiber dispersed in the matrix with different fiber adding way were discussed. The microstructure of xonotlite was observed and analyzed by scanning electron microscope and the related mechanisms were studied.


2013 ◽  
Vol 671-674 ◽  
pp. 1869-1872 ◽  
Author(s):  
Wen Min He ◽  
Shuan Fa Chen ◽  
Chuang Wang ◽  
Xue Gang Zhang ◽  
Rui Xiong

Basalt fiber (BF) has a lot of advantageous properties. The actual effectiveness of the fiber depends greatly on their dispersion degree in the composites. With the help of ultrasonic wave and a dispersant carboxymethyl cellulose (CMC), the even dispersion of short basalt fibers in water is realized. The fluidity of the basalt fiber cement mortar becomes less as the fiber content increasing. When the fluidity of mortar of BFRC is greater than 170mm, the even dispersion of short basalt fibers in BFRC can be realized. Fly ash can effectively improve the fluidity of BFRC and the density of cement matrix. When the amount of fly ash replaces the cement less than 25% by weight, it can improve both the compressive strength and tensile strength at age of 28 days.


2021 ◽  
Vol 15 (1) ◽  
pp. 165-171
Author(s):  
Yu Chen ◽  
Xingchen Li ◽  
Chuangchuang Li ◽  
Nana Zhang ◽  
Ronggui Liu ◽  
...  

Background: In order to provide space for improving the durability of engineering structures by enhancing strength, the addition of nanomaterials has become a research trend in recent years. Graphene and its derivatives have unique properties and have been used in certain fields, which has also stimulated continuous and in-depth research on whether it can improve structural strength. Objective: This paper investigates the mechanical properties and mechanism of cement-based materials reinforced by Graphene Nanoplatelets (GNPs). Methods: Macroscopically, the flexural strength and compressive strengths of cement mortar were tested. Microscopically, the structure and composition were characterized and analyzed by SEM, EDS, and XRD. Results: The results show that the mechanical properties of modified cement mortar are directly related to the GNPs content. When the GNPs content is 0.04wt%, the flexural and compressive strength can still be increased by 12.8% and 33.9% after 28 d. Furthermore, the appropriate content of GNPs dispersed in the cement matrix played a role in promoting cement hydration. The interconnection with hydration products further reduces cracks and pores so that the cement composites form a denser microstructure. Conclusion: The results obtained above would provide references for understanding the reinforcement mechanism of GNPs.


RSC Advances ◽  
2017 ◽  
Vol 7 (87) ◽  
pp. 55148-55156 ◽  
Author(s):  
Aliakbar Gholampour ◽  
Meisam Valizadeh Kiamahalleh ◽  
Diana N. H. Tran ◽  
Togay Ozbakkaloglu ◽  
Dusan Losic

This paper presents a comprehensive study to evaluate the influence of graphene oxide (GO) concentration on the physiochemical and mechanical properties of cement mortar composites.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2174
Author(s):  
Diana Gregor-Svetec ◽  
Mirjam Leskovšek ◽  
Blaž Leskovar ◽  
Urška Stanković Elesini ◽  
Urška Vrabič-Brodnjak

Polylactic acid (PLA) is one of the most suitable materials for 3D printing. Blending with nanoparticles improves some of its properties, broadening its application possibilities. The article presents a study of composite PLA matrix filaments with added unmodified and lignin/polymerised lignin surface-modified nanofibrillated cellulose (NFC). The influence of untreated and surface-modified NFC on morphological, mechanical, technological, infrared spectroscopic, and dynamic mechanical properties was evaluated for different groups of samples. As determined by the stereo and scanning electron microscopy, the unmodified and surface-modified NFCs with lignin and polymerised lignin were present in the form of plate-shaped agglomerates. The addition of NFC slightly reduced the filaments’ tensile strength, stretchability, and ability to absorb energy, while in contrast, the initial modulus slightly improved. By adding NFC to the PLA matrix, the bending storage modulus (E’) decreased slightly at lower temperatures, especially in the PLA samples with 3 wt% and 5 wt% NFC. When NFC was modified with lignin and polymerised lignin, an increase in E’ was noticed, especially in the glassy state.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 548 ◽  
Author(s):  
Leonid Agureev ◽  
Valeriy Kostikov ◽  
Zhanna Eremeeva ◽  
Svetlana Savushkina ◽  
Boris Ivanov ◽  
...  

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.


2005 ◽  
Vol 475-479 ◽  
pp. 317-320 ◽  
Author(s):  
Jing Pei Xie ◽  
Ji Wen Li ◽  
Zhong Xia Liu ◽  
Ai Qin Wang ◽  
Yong Gang Weng ◽  
...  

The in-situ Ti alloying of aluminium alloys was fulfilled by electrolysis, and the material was made into A356 alloy and used in automobile wheels. The results show that the grains of the A356 alloy was refined and the second dendrites arm was shortened due to the in-situ Ti alloying. Trough 3-hour solution treatment and 2-hour aging treatment for the A356 alloy, the microstructures were homogeneous, and Si particles were spheroid and distribute in the matrix fully. The outstanding mechanical properties with tensile strength (σb≥300Mpa) and elongation values (δ≥10%) have been obtained because the heat treatment was optimized. Compared with the traditional materials, tensile strength and elongation were increased by 7.6~14.1% and 7.4~44.3% respectively. The qualities of the automobile wheels were improved remarkably.


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