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

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.

In this paper, a study for the availability of utilizing nano cellulose, as an alternative material for carbon nanotube in nano reinforcing of cement based materials was conducted. One of the main disadvantages of carbon nanotube is its high production cost. Nano-fibrillated cellulose is a natural material extracted from cotton fibers can be used as a nano fiber material for the cement paste. The comparison is done through studying the effect of nano-cellulose on the mechanical properties; through compressive, flexural, and splitting tensile strength and on the microstructure analysis; through a scanning electron microscope, atomic force microscopy, and x-ray diffraction, and comparing with the results obtained through using carbon nanotube instead. NCL and CNT were added to cement paste with the same ratios; 0.02 wt%, 0.04 wt%, 0-06 wt%, and 0.08 wt%. Results show that the optimum percentage for both NCL and CNT was 0.04 wt%. NCL had shown to be a great alternative to CNT as Nano reinforcement to the cement composites not only to enhance the mechanical strengths but also in enhancing the microstructure of the cement matrix.


2012 ◽  
Vol 587 ◽  
pp. 97-101
Author(s):  
Bozena Vacenovska ◽  
Rostislav Drochytka ◽  
Vit Cerný

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.


2018 ◽  
Vol 245 ◽  
pp. 03002 ◽  
Author(s):  
Petr Iubin ◽  
Lubov Zakrevskaya

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.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4865
Author(s):  
Elżbieta Horszczaruk ◽  
Paweł Łukowski ◽  
Cyprian Seul

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.


1994 ◽  
Vol 344 ◽  
Author(s):  
D. Raghavan ◽  
K. Tratt ◽  
R. P. Wool

AbstractDisposal of 200 million waste tires in the US each year has become a major problem. An environmentally sound innovative technology of recycling rubber in cement matrix was examined. Using silane coupling agent the rubber was bonded to the hydrating cement making a lighter composite, which absorbed more energy than ordinary Portland cement. The bonding information was obtained by peel strength analysis. SEM was used to understand the mode of fracture in pure cement paste, cement bonded rubber composite and rubber filled cement paste. It was found that cracks propagate through the rubber particle in rubber bonded cement composite while in unbonded rubber cement mix, the cracks propagate around the interface. The density and shrinkage measurements are also discussed.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Larisa I. Nasibulina ◽  
Ilya V. Anoshkin ◽  
Albert G. Nasibulin ◽  
Andrzej Cwirzen ◽  
Vesa Penttala ◽  
...  

An effect of the quality of carbon nanotube (CNT) dispersions added to cement on paste mechanical properties has been studied. High-quality dispersions of few-walled CNT (FWCNTs) were produced in two steps. First, FWCNTs were functionalized in a mixture of nitric and sulfuric acids (70 wt.% and 96 wt.%, resp.) at80∘C. Second, functionalized FWCNTs were washed out by acetone to remove carboxylated carbonaceous fragments (CCFs) formed during CNT oxidation. Mechanical test results showed 2-fold increase in the compressive strength of the cement paste prepared from the dispersion of acetone-washed functionalized FWCNTs, which is believed to occur due to the chemical interaction between cement matrix and functional groups (–COOH and –OH). Utilisation of unwashed FWCNTs led to a marginal improvement of mechanical properties of the cement pastes, whereas surfactant-treated functionalized FWCNT dispersions only worsened the mechanical properties.


2011 ◽  
Vol 675-677 ◽  
pp. 529-535 ◽  
Author(s):  
Jian Qiang Wei ◽  
Ming Li Cao

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Tanvir Manzur ◽  
Nur Yazdani ◽  
Md. Abul Bashar Emon

Application of nanoscale science to construction material has already begun. In recent times, various nanofibers have raised the interest of researchers due to their exceptional mechanical properties and high potential to be used as reinforcement within cement matrix. Carbon nanotube (CNT) is one of the most important areas of research in the field of nanotechnology. The size and exceptional mechanical properties of CNT show their high potential to be used to produce high performance next generation cementitious composites. In this study, an attempt has been made to investigate the effect of size of CNTs on compressive strengths of CNT reinforced cement composites. Seven different sizes of multiwalled nanotubes (MWNTs) were used to produce MWNT-cement composites. A trend was observed regarding the effect of nanotube size on compressive strength of composites in most cases. MWNT with outside diameter (OD) of 20 nm or less exhibited relatively better performance. Smaller MWNT can be distributed at much finer scale and consequently filling the nanopore space within the cement matrix more efficiently. This in turn resulted in stronger composites.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianping Zhu ◽  
Genshen Li ◽  
Chunhua Feng ◽  
Libo Wang ◽  
Wenyan Zhang

Delaminated MXene was incorporated into cement to improve the properties of cement composites, and its effects on the hydration process, microstructures, and mechanical properties were investigated, respectively. The investigation results showed that delaminated MXene was well-dispersed in the cement matrix and significantly reinforced the compressive strength of cement, especially when the addition is 0.01 wt%. Meanwhile, the total hydration heat of cement hydration and the quantity of hydration products were increased with the addition of delaminated MXene. In addition, the formation of HD C-S-H gel was promoted, and the microstructure of hydrated cement became more compact.


2015 ◽  
Vol 729 ◽  
pp. 47-51
Author(s):  
Bozena Dohnalkova ◽  
Rostislav Drochytka ◽  
Jakub Hodul ◽  
Jana Hodna

This paper is the first stage of the research with the aim to identify the type of hazardous waste with the most critical production within the Czech Republic and to find the optimal composition of the cement matrix that will ensure maximum content disposal of this chosen hazardous waste. The part of the project solution will be also to define suitable testing procedure that will verify the stability of this cement composite and the impact of the inbuilt hazardous waste on the cement matrix properties.


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