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The kinetics of ettringite formation and dilatation in a blended cement with beta-hemihydrate and anhydrite as calcium sulfate

Evju, C and Hansen, Staffan LU (2005) In Cement and Concrete Research 35(12). p.2310-2321
Abstract
The phase formation, heat of hydration and dilatation in a blended cement consisting of 50 wt.% calcium aluminate cement, 25 wt.% Portland cement and 25 wt.% calcium sulfate were studied (w/c= 1). The calcium sulfate was beta-hemilrydrate, anhydrite and mixes of the two. Kinetic expressions describing the ettringite formation in the pastes with the pure calcium sulfates were found. Hydration reactions were suggested and the phase development was compared to the hydration heat by mass and heat balances. When the calcium sulfate was 75 and 50 wt.% beta-hemihydrate, the systems behaved as a linear combination of the 100 and 0 wt.% blends. At 25 wt.%, the hydration kinetics differed from the other blends. With only beta-hemihydrate, the last... (More)
The phase formation, heat of hydration and dilatation in a blended cement consisting of 50 wt.% calcium aluminate cement, 25 wt.% Portland cement and 25 wt.% calcium sulfate were studied (w/c= 1). The calcium sulfate was beta-hemilrydrate, anhydrite and mixes of the two. Kinetic expressions describing the ettringite formation in the pastes with the pure calcium sulfates were found. Hydration reactions were suggested and the phase development was compared to the hydration heat by mass and heat balances. When the calcium sulfate was 75 and 50 wt.% beta-hemihydrate, the systems behaved as a linear combination of the 100 and 0 wt.% blends. At 25 wt.%, the hydration kinetics differed from the other blends. With only beta-hemihydrate, the last 50% of ettringite formation was accompanied by expansion, mainly caused by interaction of crystals growing radially on cement grains. In the paste with only anhydrite, ettringite crystals grew in solution and produced no expansion. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ettringite, expansion, thermodynamic calculations, hydration, kinetics
in
Cement and Concrete Research
volume
35
issue
12
pages
2310 - 2321
publisher
Elsevier
external identifiers
  • wos:000233942900010
  • scopus:28044451551
ISSN
0008-8846
DOI
10.1016/j.cemconres.2004.09.012
language
English
LU publication?
yes
id
d0813428-4e7c-435b-b794-5ed7a0ae3058 (old id 211042)
date added to LUP
2007-09-21 14:13:05
date last changed
2017-10-22 04:31:41
@article{d0813428-4e7c-435b-b794-5ed7a0ae3058,
  abstract     = {The phase formation, heat of hydration and dilatation in a blended cement consisting of 50 wt.% calcium aluminate cement, 25 wt.% Portland cement and 25 wt.% calcium sulfate were studied (w/c= 1). The calcium sulfate was beta-hemilrydrate, anhydrite and mixes of the two. Kinetic expressions describing the ettringite formation in the pastes with the pure calcium sulfates were found. Hydration reactions were suggested and the phase development was compared to the hydration heat by mass and heat balances. When the calcium sulfate was 75 and 50 wt.% beta-hemihydrate, the systems behaved as a linear combination of the 100 and 0 wt.% blends. At 25 wt.%, the hydration kinetics differed from the other blends. With only beta-hemihydrate, the last 50% of ettringite formation was accompanied by expansion, mainly caused by interaction of crystals growing radially on cement grains. In the paste with only anhydrite, ettringite crystals grew in solution and produced no expansion.},
  author       = {Evju, C and Hansen, Staffan},
  issn         = {0008-8846},
  keyword      = {ettringite,expansion,thermodynamic calculations,hydration,kinetics},
  language     = {eng},
  number       = {12},
  pages        = {2310--2321},
  publisher    = {Elsevier},
  series       = {Cement and Concrete Research},
  title        = {The kinetics of ettringite formation and dilatation in a blended cement with beta-hemihydrate and anhydrite as calcium sulfate},
  url          = {http://dx.doi.org/10.1016/j.cemconres.2004.09.012},
  volume       = {35},
  year         = {2005},
}