Type
ArticleAuthors
Speziale, SergioJiang, Fuming
Mao, Zhu
Monteiro, Paulo J. M.

Wenk, Hans-Rudolf
Duffy, Thomas S.
Schilling, Frank R.
Date
2008-07Permanent link to this record
http://hdl.handle.net/10754/599634
Metadata
Show full item recordAbstract
The single-crystal elastic constants of natural ettringite were determined by Brillouin spectroscopy at ambient conditions. The six non-zero elastic constants of this trigonal mineral are: C11 = 35.1 ± 0.1 GPa, C12 = 21.9 ±0.1 GPa, C13 = 20.0 ± 0.5 GPa, C14 = 0.6 ± 0.2 GPa, C33 = 55 ± 1 GPa, C44 = 11.0 ± 0.2 GPa. The Hill average of the aggregate bulk, shear modulus and the polycrystal Young's modulus and Poisson's ratio are 27.3 ± 0.9 GPa, 9.5 ± 0.8 GPa, 25 ± 2 GPa and 0.34 ± 0.02 respectively. The longitudinal and shear elastic anisotropy are C33/C11 = 0.64 ± 0.01 and C66/C44 =0.60 ± 0.01. The elastic anisotropy in ettringite is connected to its crystallographic structure. Stiff chains of [Al(OH)6]3- octahedra alternating with triplets of Ca2+ in eight-fold coordination run parallel to the c-axis leading to higher stiffness along this direction. The determination of the elastic stiffness tensor can help in the prediction of the early age properties of cement paste when ettringite crystals precipitate and in the modeling of both internal and external sulfate attack when secondary ettringite formation leads to expansion of concrete. © 2008 Elsevier Ltd. All rights reserved.Citation
Speziale S, Jiang F, Mao Z, Monteiro PJM, Wenk H-R, et al. (2008) Single-crystal elastic constants of natural ettringite. Cement and Concrete Research 38: 885–889. Available: http://dx.doi.org/10.1016/j.cemconres.2008.02.004.Sponsors
The research was supported in part by the NSF (062464) and the Carnegie-DOE Alliance Center (CDAC). S.S. has been supported by Miller Institute for Basic Research in Science at the University of California at Berkeley during the initial stages of the project. P.J.M.M. and H.R.W. appreciate support from KAUST.Publisher
Elsevier BVJournal
Cement and Concrete Researchae974a485f413a2113503eed53cd6c53
10.1016/j.cemconres.2008.02.004