Investigation on the Mechanical Properties of a Cement-Based Material Containing Carbon Nanotube under Drying and Freeze-Thaw Conditions

Abstract

This paper aimed to explore the mechanical properties of a cement-based material with carbon nanotube (CNT) under drying and freeze-thaw environments. Mercury Intrusion Porosimetry and Scanning Electron Microscopy were used to analyze the pore structure and microstructure of CNT/cement composite, respectively. The experimental results showed that multi-walled CNT (MWCNT) could improve to different degrees the mechanical properties (compressive and flexural strengths) and physical performances (shrinkage and water loss) of cement-based materials under drying and freeze-thaw conditions. This paper also demonstrated that MWCNT could interconnect hydration products to enhance the performance of anti-microcracks for cement-based materials, as well as the density of materials due to CNT’s filling action.

Mechanical and Pressure-sensitive Properties of Cement Mortar Containing Nano-Fe2O3

“…Therefore, the strength of specimen was improved by the addition of nano-Fe 2 O 3 . It helps to compare the reinforcing mechanism in compressive strength using other nano-materials in previous research such as carbon nanotubes (CNTs) [4]. The investigation by Yazdi et al [5] also support the above results.…”

Chloride Penetration Resistance of Cement Paste Containing Different Contents of CNTs

“…Existing research [6,12] showed that, as a nano-material, CNTs can fill and block the pores through the effect of micro-filling in the cement-based composites, and play a role in reducing and refining the pores. Li et al [8] showed that the addition of MWCNT led to a reduction of lower water evaporation, indicating that there were less open pores in the specimens of cement-based composites with CNTs. Thus, the cementbased composites with CNTs may have the better performance of water retention which can make unhydrated particles hydrate continuously compared with the cement mortar specimens which unincorporated CNTs, and make the structure more compact so that the distribution of pore diameter has a great improvement, and then the harmful pores and more harmful pores have a significant improvement.…”

“…Han et al [7] found that CNTs can effectively improve the durability properties of cement-based composites. Li et al [8] discovered that MWCNT could improve some mechanical properties and physical performances of cement-based composites under drying and freeze-thaw conditions from different degrees. Li et al [9] found that NS may act as an ideal admixture for improving both the interactive behaviors between CNTs and cement matrix and the damping properties of cement composite.…”

Compressive Strength of Cement Mortar Containing Carbon Nanotubes (CNTs) under Sulfate Attack and Dry-wet Cycling Environment

“…Han et al [8] found that multiwalled CNT (MWCNT) could decrease the absorption coefficient, water permeability and gas permeability of cement-based materials; Weiwen Li et al [9] found that with addition of carbon nanotube to the cement mortar, pores with a diameter of bigger than 200 nm are likely to be refined to 50-100 nm; the disconnection of pores was also improved. However, CNT was also reported to have detrimental effects on durability.…”