scholarly journals Efficient Use of Graphene Oxide and Silica Fume in Cement-Based Composites

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6541
Author(s):  
Ahmad Abdullah ◽  
Mohamed Taha ◽  
Mohamed Rashwan ◽  
Mohamed Fahmy
Keyword(s):  
Graphene Oxide ◽  
Silica Fume ◽  
Cement Composite ◽  
Mix Design ◽  
Design Parameters ◽  
Cement Matrix ◽  
Cement Composites ◽  
Test Results ◽  
Main Criterion ◽  
Simplified Approach

Incorporation of graphene oxide (GO) and silica fume (SF) to cement composites enhances their mechanical properties if suitable proportional amounts of GO and SF are used. This study presents a simplified approach to determine experimentally the optimum GO and SF contents that should be added to the cementitious mixture to obtain a proper and stable dispersion of GO sheets within the cement matrix. Composite mortar specimens with different GO and SF contents were designed and tested under flexural and compression loading. The phase formation and the microstructure of selected samples were also investigated to give an in-depth interpretation of the test results. The main criterion to determine the GO and SF contents was the ultimate strength required of the GO–cement composite. It was found that there was a composite interaction between the SF and GO contents in the cementitious mixture, which an envelope surface could describe if all other mix design parameters are kept constant.

Graphene Oxide/Cement Composites for Electromagnetic Interference Shielding

2014 ◽  
Vol 809-810 ◽  
pp. 485-489 ◽  
Author(s):  
Dan Zhao ◽  
Juan Chen ◽  
Qun Gao ◽  
He Yi Ge
Keyword(s):  
Graphene Oxide ◽  
Electromagnetic Interference ◽  
Early Stage ◽  
Cement Composite ◽  
Vital Role ◽  
Cement Matrix ◽  
Cement Composites ◽  
Shielding Effectiveness ◽  
Electromagnetic Shielding Effectiveness ◽  
Modified Hummers Method

Graphene oxide (GO) synthesized through a modified Hummers’ method was added into cement matrix to prepare GO/cement. The microstructure, mechanical properties, and the electromagnetic shielding effectiveness (SE) at 8.2–12.4 GHz of GO/cement composite were investigated. It has been observed that incorporation of GO in the cement matrix can regulate to form flower-like hydration crystals and distinctly enhance the flexural/compressive early stage strength of GO/cement composites. Furthermore, GO sheets played a vital role in effectively improve the shielding effectiveness with the dominant shielding mechanism of absorption of electromagnetic radiation.

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
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Graphene Oxide ◽  
Cement Mortar ◽  
Cement Matrix ◽  
Cement Composites ◽  
Xrd Diffraction ◽  
Calcium Silicate Hydrates ◽  
The Matrix ◽  
Scanning Electron

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.

Microstructural Study of Cement Composites Produced by Hazardous Waste Stabilization/Solidification

2012 ◽  
Vol 587 ◽  
pp. 97-101
Author(s):  
Bozena Vacenovska ◽  
Rostislav Drochytka ◽  
Vit Cerný
Keyword(s):  
Fly Ash ◽  
Hazardous Waste ◽  
Cement Composite ◽  
Cement Matrix ◽  
Main Task ◽  
Cement Composites ◽  
Microstructural Study ◽  
Waste Stabilization ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

This paper deals with the chosen hazardous waste solidification/stabilisation (S/S) under the catalogue code 190811 using cement matrix with addition of classic fly ash and fluid fly ash as secondary raw binders. The main task of the research works was a microstructural study of the most successful S/S formula that will be used for development of new reclamation material. The S/S process product was subject to X-Ray analysis and to the electron microscopy analysis two years after its production to evaluate the possibility of degradation of the cement composite and releasing the contaminants into environment.

scholarly journals Experimental Study on Mechanical and Functional Properties of Reduced Graphene Oxide/Cement Composites

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3015 ◽  
Author(s):  
Ning Zhang ◽  
Wei She ◽  
Fengyin Du ◽  
Kaili Xu
Keyword(s):  
Graphene Oxide ◽  
Electric Conductivity ◽  
Reduced Graphene Oxide ◽  
Cement Composite ◽  
Cementitious Material ◽  
Cement Composites ◽  
Morphological Effect ◽  
Cement Material ◽  
Reduced Graphene ◽  
Electric Shielding

This study develops a novel self-sensing cement composite by simply mixing reduced graphene oxide (rGO) in cementitious material. The experimental results indicate that, owing to the excellent dispersion method, the nucleation and two-dimensional morphological effect of rGO optimizes the microstructure inside cement-based material. This would increase the electric conductivity, thermal property and self-induction system of cement material, making it much easier for cementitious material to better warn about impending damage. The use of rGO can improve the electric conductivity and electric shielding property of rGO-paste by 23% and 45%. The remarkable enhancement was that the voltage change rate of 1.00 wt.%-rGO paste under six-cycle loads increased from 4% to 12.6%, with strain sensitivity up to 363.10, without compromising the mechanical properties. The maximum compressive strength of the rGO-mortar can be increased from 55 MPa to 71 MPa. In conclusion, the research findings provide an effective strategy to functionalize cement materials by mixing rGO and to achieve the stronger electric shielding property and higher-pressure sensitivity of rGO–cement composites, leading to the development of a novel high strength self-sensing cement material with a flexural strength up to 49%.

scholarly journals Soil-concrete for use in the 3D printers in the construction of buildings and structures

2018 ◽  
Vol 245 ◽  
pp. 03002 ◽  
Author(s):  
Petr Iubin ◽  
Lubov Zakrevskaya
Keyword(s):  
Rheological Properties ◽  
Cement Paste ◽  
Clay Soil ◽  
Cement Composite ◽  
Cement Composites ◽  
Test Results ◽  
Flow Table ◽  
Key Factor ◽  
3D Printers ◽  
The Cost

Nowadays, the construction of cement composite using 3D printers is considered one of the most promising methods of automation of building processes. However, the compositions of cement composites have several disadvantages, such as high cost, short workability and etc. It has been suggested that clay soil as an additive will help to solve these problems partially. The aim of the work is development the cement compositions with clay soil, for use in 3D printers to construction. The composite consists of cement paste with clay soil and additives. To study printability of a composite the rheological properties in a fresh state were studied. The study of the rheological properties of composites was carried out using a flow table test for mortar. The key factor for determining the suitability of the composite for printing was accepted the diameter of the cone after shaking. The test results showed the possibility of replacing cement paste with clay soil up to 25% which leads to a reduction in the cost and an increase in printability with a slight decrease in the strength of the obtained material to 7%. Utilizing of soil from the construction site provides maximum economic efficiency of the material application.

scholarly journals Influence of Dispersing Method on the Quality of Nano-Admixtures Homogenization in Cement Matrix

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4865
Author(s):  
Elżbieta Horszczaruk ◽  
Paweł Łukowski ◽  
Cyprian Seul
Keyword(s):  
High Speed ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
Cement Composite ◽  
Cement Matrix ◽  
Cement Composites ◽  
Nano Sio2 ◽  
Mechanical Stirring ◽  
Physico Chemical ◽  
Nano Fe3o4

In recent years, a nano-modification of the cement composites allowed to develop a number of new materials. The use of even small amount of nano-admixture makes possible not only to improve the physico-mechanical properties of the cement materials, but also to obtain the composite with high usability, optimised for the given application. The basic problem of nano-modification of the cement composites remains the effectiveness of dispersing the nanomaterials inside the cement matrix. This paper deals with the effect of the type and size of the nanoparticles on the tendency to their agglomeration in the cement matrix. The main techniques and methods of dispersing the nanomaterials are presented. It has been demonstrated, on the basis of the results of testing of three nanomodifiers of 0D type (nano-SiO2, nano-Fe3O4 and nano-Pb3O4), how the structure and properties of the nanomaterial affect the behaviour of the particles when dissolving in the mixing water and applying a superplasticiser. The nanoparticles had similar size of about 100 nm but different physico-chemical properties. The methods of dispersing covered the use of high-speed mechanical stirring and ultrasonication. The influence of the method of nano-modifier dispersing on the mechanical performance of the cement composite has been presented on the basis of the results of testing the cement mortars modified with 3% admixture of nano-SiO2.

scholarly journals Damping Property of a Cement-Based Material Containing Carbon Nanotube

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Wei-Wen Li ◽  
Wei-Ming Ji ◽  
Yi Liu ◽  
Feng Xing ◽  
Yu-Kai Liu
Keyword(s):  
Carbon Nanotube ◽  
Cement Paste ◽  
Load Transfer ◽  
Cement Composite ◽  
Mechanical Analysis ◽  
Cement Matrix ◽  
Cement Composites ◽  
Strength Index ◽  
Damping Property ◽  
Reduction Capacity

This study aimed to explore the damping property of a cement-based material with carbon nanotube (CNT). In the study, the cement composites with different contents of CNT (0 wt%, 0.033 wt%, 0.066 wt%, and 0.1 wt%) were investigated. Logarithmic Decrement method and Dynamic Mechanical Analysis (DMA) method were utilized to study the damping property of CNT/cement composite. The influences of CNT on pore size distribution and microstructure of composite were analyzed by Mercury Intrusion Porosimetry (MIP) and Scanning Electron Microscopy (SEM), respectively. The experimental results showed that CNT/cement composite presented higher flexural strength index than that of a pure cement paste. Additional CNT could improve the vibration-reduction capacity of cement paste. Furthermore, the experiments proved that CNT could bridge adjacent hydration products and support load transfer within cement matrix, which contributed to the energy dissipation during the loading process.

Effect and Microscopic Mechanisms of Slag Micropowder on the Reinforcement of CaCO3 Whisker in Cement Composites

2011 ◽  
Vol 675-677 ◽  
pp. 529-535 ◽  
Author(s):  
Jian Qiang Wei ◽  
Ming Li Cao
Keyword(s):  
Cement Composite ◽  
Cement Matrix ◽  
Cement Composites ◽  
X Ray Diffraction ◽  
Interfacial Bond ◽  
Interfacial Bond Strength ◽  
Slag Powder ◽  
Pull Out ◽  
Reinforced Cement ◽  
Powder Content

Whisker pull-out, which indicates that the interfacial bond strength of whiskers/cement is not high enough, is dominant in the microstructure of whisker-reinforced cement fractured surfaces. The weak interfacial bond of whiskers in cement matrix severely restrained the further improvement of properties. Superfine slag powder was used to modify and improve the strength and bond behavior of whisker-reinforced cement. Crystal structures, microcosmic appearances and characterizations of Slag Micro powder and the composite were studied by X-ray diffraction (XRD), and scan electron microscope (SEM/EDS), etc. Effect and mechanisms of different Slag powder content on the micro-structure and macro-properties of cement composite were investigated. The results show that Slag Micropowder can modify and improve the microstructure, interfacial and mechanical properties of whisker-reinforced cement.

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