The 4th Asian Concrete Federation Symposium on Emerging Technologies for Structural Longevity (ACF2023- ETSL)

19 / 2022-03-09 14:54:42

Effect and mechanism analysis of functionalized multi-walled carbon nanotubes (MWCNTs) on C-S-H gel

MWCNTs,C-S-H,C/S,Carboxylate groups

The effect and the interaction mechanism of functionalized multi-walled carbon nanotubes (MWCNTs) on C-S-H gel were studied in this paper. Fourier infrared spectroscopy, acid-base titration, Raman spectroscopy and transmission electron microscopy were utilized to analyze the pristine MWCNTs and functionalized MWCNTs, showing that the degree of graphitization of the functionalized MWCNTs reduced.Afterward, the MWCNTs/C-S-H composite was prepared by well-dispersing the functionalized MWCNTs and the C-S-H. The experimental results showed that for the C-S-H produced with different designed molar ratios of CaO to nanosilica (C/S^D), the measured molar ratio of Ca to Si (C/S^M) of the C-S-H decreased and the interlayer spacing of the C-S-H increased with the increase of the amount of the functionalized MWCNTs. When C/S^D=0.8, the polymerization degree of the C-S-H decreased and the proportion of the capillary pores increased gradually with increasing the amount of the functionalized MWCNTs. When the values of C/S^D were 1.5 and 2.0, the trends the polymerization degree and the proportion of the capillary pores of C-S-H were opposite to those of C/S^D=0.8.