scholarly journals Effect of multi-walled carbon nanotubes (MWCNTs) on the strength development of cementitious materials

2019 ◽  
Vol 8 (1) ◽  
pp. 1203-1211 ◽  
Author(s):  
Ali Naqi ◽  
Naseem Abbas ◽  
Nida Zahra ◽  
Abasal Hussain ◽  
Syed Qasim Shabbir
2020 ◽  
Vol 9 (1) ◽  
pp. 93-104
Author(s):  
Mingrui Du ◽  
Yuan Gao ◽  
Guansheng Han ◽  
Luan Li ◽  
Hongwen Jing

AbstractMulti-walled carbon nanotubes (MWCNTs) have been added in the plain cementitious materials to manufacture composites with the higher mechanical properties and smart behavior. The uniform distributions of MWCNTs is critical to obtain the desired enhancing effect, which, however, is challenged by the high ionic strength of the cement pore solution. Here, the effects of methylcellulose (MC) on stabilizing the dispersion of MWCNTs in the simulated cement pore solution and the viscosity of MWCNT suspensions werestudied. Further observations on the distributions of MWCNTs in the ternary cementitious composites were conducted. The results showed that MC forms a membranous envelope surrounding MWCNTs, which inhibits the adsorption of cations and maintains the steric repulsion between MWCNTs; thus, the stability of MWCNT dispersion in cement-based composites is improved. MC can also work as a viscosity adjuster that retards the Brownian mobility of MWCNTs, reducing their re-agglomerate within a period. MC with an addition ratio of 0.018 wt.% is suggested to achieve the optimum dispersion stabilizing effect. The findings here provide a way for stabilizing the other dispersed nano-additives in the cementitious composites.


2011 ◽  
Vol 284-286 ◽  
pp. 310-313
Author(s):  
Zhi Gang Liu ◽  
Li Rong Yang ◽  
Jun Cong Wei ◽  
Bao Hui Zhao ◽  
Xiao Xin Feng

The compressive strength and piezoresistive property of cement mortar with low adding level of multi-walled carbon nanotubes (MWCNTs) were investigated. Experimental results showed that the compressive strength of the MWCNTs/cement mortars increased with the adding amount of MWCNTs content for all the curing ages. Silica fume promoted the compressive strength development by well bonding with MWCNTs and filling effect. The electrical resistance changed synchronously with the compressive strength and the amount of the changes varied with the stress and MWCNTs addition levels. Higher MWCNTs doping level improved the piezoresistive sensitivity of the mortar. The mortar with silica fume (5-10% by weight of cement) exhibited better piezoresistive response than that without silica fume at the same MWCNTs doping levels.


2016 ◽  
Vol 711 ◽  
pp. 232-240 ◽  
Author(s):  
Ling Shi Meng ◽  
Christopher K.Y. Leung ◽  
Geng Ying Li

This paper studies the effects of multi-walled carbon nanotubes (MWCNTs) on the mechanical properties and durability of polymer latex-modified cement mortar. Latex-modified cementitious materials possess many advantages. However, reduction of mechanical properties due to the introduction of an amorphous structure within the cement composite has limited its application. In this study, multi-walled carbon nanotubes functionalised with carboxyl group (MWCNTs-COOH), ranging from 0% to 0.15% by weight, are added into mortar modified with 0.6 wt.% polyvinyl alcohol (PVA) latex. Mechanical properties including compressive strength and flexural strength are measured. Water absorption test and rapid chloride diffusion test are performed to assess durability performance. Results indicate considerable increase of compressive strength and flexural strength, as well as improvement in durability, by the addition of MWCNTs-COOH. With Scanning Electron Microscopy conducted on both the latex solution and cement composite, the microstructural changes resulted from MWCNT addition are revealed.


Acta Naturae ◽  
2011 ◽  
Vol 3 (1) ◽  
pp. 99-106 ◽  
Author(s):  
E A Smirnova ◽  
A A Gusev ◽  
O N Zaitseva ◽  
E M Lazareva ◽  
G E Onishchenko ◽  
...  

2003 ◽  
Vol 772 ◽  
Author(s):  
T. Seeger ◽  
G. de la Fuente ◽  
W.K. Maser ◽  
A.M. Benito ◽  
A. Righi ◽  
...  

AbstractCarbon nanotubes (CNT) are interesting candidates for the reinforcement in robust composites and for conducting fillers in polymers due to their fascinating electronic and mechanical properties. For the first time, we report the incorporation of multi walled carbon nanotubes (MWNTs) into silica-glass surfaces by means of partial surface-melting caused by a continuous wave Nd:YAG laser. MWNTs were detected being well incorporated in the silica-surface. The composites are characterized using scanning electron microscopy (SEM) and Raman-spectroscopy. A model for the composite-formation is proposed based on heatabsorption by MWNTs and a partial melting of the silica-surface.


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