Investigating the compatibility of nickel coated carbon nanotubes and cementitious composites through experimental evidence and theoretical calculations. (20th September 2021)

• Record Type: Journal Article
• Authors: Wang, Danna; Dong, Sufen; Wang, Xinyue; Ashour, Ashraf; Lv, Xingjun; Han, Baoguo
• Is Part Of: Construction & building materials. Volume 300(2021)
• Publication Date: 2021-09-20
• Subjects: Cementitious composites -- Nickel coated multi-walled carbon nanotubes -- Mechanical properties -- Aspect ratio -- Water to cement ratio; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2021.124340
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Compatibility of nickel coated CNT (NiMCNT) and cementitious materials were studied. Adding NiMCNTs leads to an increase of 19.65%/116.78% in flexural strength/toughness. NiMCNT has good compatibility to composites with P·O 42.5R cement and 0.24 w/c ratio. NiMCNT at 0.03 vol.%/large aspect ratio has optimal enhancement effect on composites. A strength calculation model for NiMCNT filled cementitious composites is proposed. Abstract: Nickel coated multi-walled carbon nanotubes (NiMCNTs) are favorable reinforcing nanofillers for modifying cementitious composites due to their preeminent mechanical properties, electrical conductivity, thermal properties and dispersibility. This paper investigates the mechanical properties and compatibility of NiMCNTs filled cementitious composites, having two different types of cement, two water to cement ratios, and two dosages of five types of NiMCNTs. The results show that 0.06 vol% NiMCNTs with small aspect ratios can significantly enhance the mechanical properties of cementitious composites, while NiMCNTs with large aspect ratios play a better strengthening effect at 0.03 vol%. The flexural strength/toughness of cementitious composites containing 0.06 vol% NiMCNTs with an aspect ratio of 200 can be increased by 19.65%/116.78%. Adding 0.03 vol% NiMCNTs with an aspect ratio of 1000 enhances the compressive strength/toughness of composites by 18.61%/47.44%. Besides, NiMCNTs have preferable compatibility to cementitious composites prepared by P·O 42.5R cement with a water to cement ratio of 0.3. The enhancement mechanism is related to the denser microstructure and effective suppression of microcracks in the cementitious matrix by NiMCNTs with filling, bridging and pull-out effects, as well as the high interface bond strength between NiMCNTs and matrix. A strength prediction model for NiMCNTs reinforced cementitious composites is also established to estimate the mechanical strength of cementitious composites containing NiMCNTs with different aspect ratios/contents, showing a small relative error within ±6%/±13% for predicted flexural/compressive strength values in comparison with the experimental results.