scholarly journals Carbon Nanotubes and Resistance to Freeze-Thaw Cycles

2021 ◽  
Vol 12 (05) ◽  
pp. 239-254
Author(s):  
Sena Peace Hounkpe ◽  
Valéry K. Doko ◽  
Smith O. Kotchoni ◽  
Hui Li ◽  
Abbas T. Datchossa
Keyword(s):  
Carbon Nanotubes ◽  
Freeze Thaw

Effect of Carbon Nanotubes’ Diameter on Freeze-Thaw Resistance of Cement Paste

2020 ◽  
Vol 36 (4) ◽  
pp. 437-449
Author(s):  
Wei Tian ◽  
Fangfang Gao
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Cement Paste ◽  
Microstructural Analysis ◽  
Optimal Size ◽  
Multiwalled Carbon ◽  
Freeze Thaw ◽  
20 Nm

ABSTRACTThis paper aims to investigate the freeze-thaw resistance of cement-paste containing with different diameter and content of multiwalled carbon nanotubes (MWCNTs) in terms of mechanical properties and microstructure. Three groups of cement-paste with MWCNTs diameter of 10-20 nm, 20-40 nm and 40-60 nm were prepared by incorporating 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt% MWCNTs by cement weight. Experimental results showed that the addition of 0.1 wt% MWCNTs with diameters of 10–20 nm effectively improved the freeze-thaw resistance of cement-paste. In addition, microstructural analysis of these cement-paste specimens showed that MWCNTs addition increased the materials’ initial porosity, but a proper amount of MWCNTs decreased the porosity of cement-paste after freeze-thaw cycles and effectively improved the pore size distribution. MWCNTs 10–20 nm in diameter were found to be the optimal size for improving the microstructure of these MWCNTs cement-paste

scholarly journals Effect of Adding Carbon Nanotubes on the Freeze-Thaw and Thermal Fatigue Resistance of Latex Modified Mortar

Fibers ◽  
2018 ◽  
Vol 6 (2) ◽  
pp. 19
Author(s):  
Ahmed Abdel-Mohti ◽  
Eslam Soliman ◽  
Hui Shen
Keyword(s):  
Carbon Nanotubes ◽  
Fatigue Resistance ◽  
Thermal Fatigue ◽  
Thermal Fatigue Resistance ◽  
Freeze Thaw

scholarly journals Structural Properties and Damage Detection Capability of Carbon Nanotube Modified Mortars after Freeze-Thaw

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1747
Author(s):  
Panagiota Alafogianni ◽  
Ilias Tragazikis ◽  
Anastasios Balaskas ◽  
Nektaria-Marianthi Barkoula
Keyword(s):  
Carbon Nanotubes ◽  
Acoustic Emission ◽  
Carbon Nanotube ◽  
Fracture Energy ◽  
Structural Properties ◽  
Acoustic Emission Activity ◽  
Detection Capability ◽  
Freeze Thaw ◽  
Damage Sensing ◽  
Emission Activity

Here we explore the structural properties and damage sensing of cementitious mortars after a freeze-thaw process (F-T) as a function of nano-modification. For this purpose, carbon nanotubes were added at 0.2–0.8 wt.% cement using two different dispersive agents. F-T resulted in reduced fracture energy in nano-modified specimens prepared using superplasticizer as a dispersant while the opposite held true for the surfactant-containing ones. All nano-modified mortars possessed significantly higher fracture energy compared to the plain specimens after F-T (up to 73% improvement). The acoustic emission activity was lower after F-T, while acoustic emission indicators revealed a more tensile mode of fracture in both plain and nano-modified mortars.

Multi-Walled Carbon Nanotubes Enhanced the Performance of Epoxy Asphalt Pavement Binder

2020 ◽  
Vol 20 (8) ◽  
pp. 5037-5042
Author(s):  
Chuansheng Chen ◽  
Chen Wang ◽  
Guoping Qian ◽  
Bowen Zhang ◽  
Bo Liang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Synergistic Effect ◽  
Dynamic Stability ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Freeze Thaw ◽  
Mechanical Stirring ◽  
Epoxy Asphalt ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Modifying epoxy asphalt with nanomaterials is an effective method to enhance the performance of epoxy asphalt binder. The carbon nanotubes were modified and carbon nanotubes/epoxy asphalt (CNTs-EA) was fabricated by mechanical stirring. The performanceof CNTs-EA pavement binder (CNTs-EAPB) was analyzed by immersion marshall’s, freeze-thaw splitting and dynamic stability tests. Experimental results showed that the dynamic stability and freeze-thaw splitting intensity of matrix asphalt binder (MAB) were improved by 118.6% and 85%, respectively. While the dynamic stability of CNTs-EAPB remained 90.8% under soaking water which was more than 77.44% of matrix asphalt and reached 5801 times per mm. This enhancement is mainly attributed to excellent characteristics of CNTs as well as the effective synergistic effect between CNTs and epoxy resin.

Structural phenomena in the growth of carbon nanotubes

1993 ◽  
Vol 51 ◽  
pp. 750-751
Author(s):  
Jun Jiao
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Carbonaceous Material ◽  
Cluster Growth ◽  
Structural Elements ◽  
Rich Variety ◽  
Different Shapes ◽  
Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

Carbon nanotubes: Hot display

2009 ◽  
Vol 1 (1) ◽  
pp. 9-9
Keyword(s):  
Carbon Nanotubes
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