²⁹Si NMR Characterization of Silica Tetrahedron in the Silica Fume Simulate Hydration

Abstract:

As the major structure of silica fume, the change of silica tetrahedron in the pozzolanic reaction during the hydration has not been revealed clearly in previous studies. In this study, 29Si solid-state MAS NMR was used to characterize the silica tetrahedron change of the silica fume in saturated alkali solution with 0.9, 1.2, 1.5 and 1.8 four different calcium/silica ratios. The amorphous Q4 silica tetrahedron structure in silica fume changed into Q1 silica tetrahedron at 1 day. Q2 silica tetrahedron formed from Q1 silica tetrahedron within 3 days. Q1 and Q2 silica tetrahedron reached a balance until silica fume completed pozzolanic reaction and the Q4 silica tetrahedron exhausted. The coexistence of Q1 and Q2 silica tetrahedron benefited the physical properties increase of cementitious system. 29Si solid-state MAS NMR results proved that the chain length of silica tetrahedron in C-S-H shortened in the silica fume hydration while the C/S ratio increased.

• Periodical: Key Engineering Materials (Volume 539)
• Pages: 1-4
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.539.1
• Online since: January 2013
• Authors: Xiao Jun Wang, Xiao Yao Wang, Hong Fei Zhu, Chen Qian
• Keywords: Hydration, Nuclear Magnetic Resonance, Silica Fume (SF), Silica Tetrahedron

References

[1] R. Siddique and N. Chahal: Resources, Conserv. Recycl. Vol. 55 (2011), p.739.

[2] H.W. Song, S.W. Pack and S.H. Nam: Constr. Build. Mater. Vol. 24 (2010), p.315.

[3] N. Neithalath, J. Persun and A. Hossain: Cem. Concr. Res. Vol. 39 (2009), p.473.

[4] E.H. Kadri, R. Duval, S. Aggoun, et al.: ACI Mater. J. Vol. 106 (2009), p.107.

[5] E. A. El-alfi, A. M. Radwan, H. Abu-el-naga: Ceramics-Silikaty. Vol. 55 (2011), p.147.

[6] J. Zelic, D. Rusic and R. Krstulovic: Cem. Concr. Res. Vol. 34(2004), p.2319.

[7] R. Duval and E.H. Kadri: Cem. Concr. Res. Vol. 28 (1998), p.533.

[8] Y.J. Ji and H.C. Jone: Cem. Concr. Res.Vol. 33 (2003), p.1543.

[9] G.A. Rao: Cem. Concr. Res. Vol. 33 (2003), p.1765.

[10] J. Zelic, D. Rusic and R. Krstulovic: Cem. Concr. Res.Vol. 34 (2004), p.2319.

[11] G.A. Rao: Cem. Concr. Res. Vol. 31 (2001), p.1141.

[12] X. Wang, H. Lee, S.W. Shin, et al.: Magazine Concr. Res. Vol. 62 (2010), p.637.

[13] E.A. Kishar, D.A: Ahmed and M.R. Mohammed: Adv. Cem. Res. Vol. 22 (2010), p.143.

[14] E.H. Kadri and R. Duval: Constr. Build. Mater. Vol. 23 (2009), p.3388.

[15] G.A. Rao: Cem. Concr. Res. Vol. 33 (2003), p.1765.

[16] F. Brunet, P. Bertani, T. Charpentier, et al.: J. Phys. Chem. B Vol. 108 (2004), p.15494.

[17] L.N. Lv, X.G. Zhao, Y.J. He, et al.: Effect of C/S ratio on morphology and structure of calcium silicate hydrate. Presented at 1st Conf. Cement Branch of Chin. Ceram. Soc. (Jiaozuo, China, 2009).

[18] X.J. Wang, W.W. Zhu, H.Wang: J. Wuhan Univ. Technol. – Mater. Sci. Ed. Vol. 26 (2011), p.972.

[19] M.D. Andersen, H.J. Jakobsen and J. Skibsted: Inorg. Chem. Vol. 42 (2003), p.2280.