Mechanical properties of Portland cement mortar containing multi-walled carbon nanotubes at elevated temperatures

2018 ◽  
Vol 176 ◽  
pp. 482-489 ◽  
Author(s):  
Arash Sedaghatdoost ◽  
Kiachehr Behfarnia
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Portland Cement ◽  
Elevated Temperatures ◽  
Cement Mortar ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Dispersion of Multi-Walled Carbon Nanotubes in Portland Cement Concrete Using Ultra-Sonication and Polycarboxylic Based Superplasticizer

2015 ◽  
Vol 802 ◽  
pp. 112-117 ◽  
Author(s):  
Ali Yousefi ◽  
Norazura Muhamad Bunnori ◽  
Mehrnoush Khavarian ◽  
Taksiah A. Majid
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Portland Cement ◽  
Cement Matrix ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Uniform Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Sonication Technique ◽  
Walled Carbon Nanotubes

The potential properties of carbon nanotube-cement based materials strongly depend on the dispersion of carbon nanotubes (CNTs) within the cement matrix and the bonding between CNTs and the hydrated cement. The homogeneous dispersion of CNTs in the cement matrix yet is one of the main challenges due to strong van der Waals forces between nanotubes. In this study, a polycarboxylic ether based superplasticizer and ultra-sonication technique was used for dispersion of multi-walled carbon nanotubes (MWCNTs). Portland cement concrete specimens with different concentrations of MWCNTs (0.04 and 0.1 % by the weight of cement), with and without the presence of superplasticizer were investigated. Compressive strength test results revealed a significant improvement in mechanical properties of sample containing 0.1 % MWCNTs and 0.2 % superplasticizer. Moreover, field emission scanning electron microscopy (FESEM) images of fractured surfaces of hardened specimens showed a good dispersion of MWCNTs within the cement matrix. This method was developed to facilitate the uniform dispersion of MWCNTs in the cementitious concrete for better reinforcement in nanoscale and mechanical properties enhancement by transfer of load between the nanotubes and matrix.

Effect of Multi-Walled Carbon Nanotubes on Mechanical Properties and Durability of Latex-Modified Cement Mortar

2016 ◽  
Vol 711 ◽  
pp. 232-240 ◽  
Author(s):  
Ling Shi Meng ◽  
Christopher K.Y. Leung ◽  
Geng Ying Li
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Mortar ◽  
Cement Composite ◽  
Cementitious Materials ◽  
Chloride Diffusion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

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.

Mechanism of the Modified Carbon Nanotubes Toughening DSP Cement Mortar

2015 ◽  
Vol 723 ◽  
pp. 406-409
Author(s):  
Jing Mei Tan ◽  
Ai Guo Wang ◽  
Wen Jun Su
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Surface ◽  
Cement Hydration ◽  
Cement Mortar ◽  
Hydration Products ◽  
Multi Walled Carbon Nanotubes ◽  
Modified Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The analysis is made for the modification of multi-walled carbon nanotubes and the mechanical properties and microstructure of the modified carbon nanotubes toughening DSP cement mortar, the existence and toughening effect of modified carbon nanotubes on the fracture surface of materials were analyzed. Results shows that, the surface of the carbon nanotubes in the sample is covered with cement hydration products, with the carbon nanotubes in drawing state on the fracture surface and both ends of the tube connected firmly with cement materials, thus carbon nanotubes improve the toughness of materials effectively.

The Characteristics of Alkali-Activated Slag Mortar containing Multi-Walled Carbon Nanotubes at Elevated Temperature

2021 ◽  
pp. 1-23
Author(s):  
Arash Sedaghatdoost ◽  
Kiachehr Behfarnia ◽  
Mohammad Bayati ◽  
Ali Hendi ◽  
Mohammad Sadegh Vaezi
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Mass Loss ◽  
Elevated Temperatures ◽  
Alkali Activated Slag ◽  
Ambient Temperatures ◽  
Multi Walled Carbon Nanotubes ◽  
Activated Slag ◽  
Walled Carbon Nanotubes ◽  
Alkali Activated

In the present paper, the effect of using multi-walled carbon nanotubes (MWCNTs) with different concentrations of 0, 0.05, 0.1, and 0.15 wt% on the mechanical properties and microstructure of alkali-activated slag (AAS) mortars at temperatures of 23, 200, 400, 600, and 800°C was investigated. In order to investigate the strength parameters of specimens, the mechanical strength and mass-loss of the specimens at ambient temperatures and after exposure to elevated temperatures were determined. Petrographic image analysis also was conducted to analyze the microstructures of the specimens. Moreover, the Image processing toolbox of Matlab software was used to calculate the pore area of the samples at room temperature. The results showed that the application of MWCNTs improved the mechanical properties of the AAS mortars at ambient and elevated temperatures. The addition of the MWCNTs improved the mechanical properties of the AAS mortars up to 69 and 85% for compressive and flexural strength, respectively. At 400°C, compressive strength increment of the specimens compensated the deterioration rate, which was about 3% mass-loss and this temperature should be considered the maximum tolerable degree for AAS mortars.

scholarly journals Enhancement of out-of-plane mechanical properties of carbon fiber reinforced epoxy resin composite by incorporating the multi-walled carbon nanotubes

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Seyed Ali Mirsalehi ◽  
Amir Ali Youzbashi ◽  
Amjad Sazgar
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Test ◽  
Epoxy Resin ◽  
Laminate Composite ◽  
Filament Winding ◽  
Hybrid Nanocomposites ◽  
Out Of Plane ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractIn this study, epoxy hybrid nanocomposites reinforced by carbon fibers (CFs) were fabricated by a filament winding. To improve out-of-plane (transverse) mechanical properties, 0.5 and 1.0 Wt.% multi-walled carbon nanotubes (MWCNTs) were embedded into epoxy/CF composites. The MWCNTs were well dispersed into the epoxy resin without using any additives. The transverse mechanical properties of epoxy/MWCNT/CF hybrid nanocomposites were evaluated by the tensile test in the vertical direction to the CFs (90º tensile) and flexural tests. The fracture surfaces of composites were studied by scanning electron microscopy (SEM). The SEM observations showed that the bridging of the MWCNTs is one of the mechanisms of transverse mechanical properties enhancement in the epoxy/MWCNT/CF composites. The results of the 90º tensile test proved that the tensile strength and elongation at break of nanocomposite with 1.0 Wt.% MWCNTs improved up to 53% and 50% in comparison with epoxy/CF laminate composite, respectively. Furthermore, the flexural strength, secant modulus, and elongation of epoxy/1.0 Wt.% MWCNT/CF hybrid nanocomposite increased 15%, 7%, and 9% compared to epoxy/CF laminate composite, respectively.

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