Comparison of solvent exchange and vacuum drying techniques to remove free water from early age cement-based materials

Title: Comparison of solvent exchange and vacuum drying techniques to remove free water from early age cement-based materials
Author(s): E. Knapen, O. Cizer
Paper category : conference
Book title: 2nd International RILEM Symposium on Advances in Concrete through Science and Engineering
Editor(s): J. Marchand, B. Bissonnette, R. Gagné, M. Jolin and F. Paradis
Print-ISBN: 2-35158-003-6
e-ISBN: 2351580028
Publisher: RILEM Publications SARL
Publication year: 2006
Nb references: 14
Language: English

Abstract: In order to study the progress of hydration at early ages in cement-based materials by thermal analysis, FT-IR and XRD, the ongoing hydration reactions should be stopped after different periods of time by complete removal of the free water from the material, i.e. the water which has not yet participated in the hydration reactions. The replacement of the cement paste pore water by a low surface-tension organic fluid is a common technique to stop the hydration prior to thermal analysis. However, it seems that an interaction is taking place between the organic liquid and the cement hydrates which results in the formation of carbonate-like compounds and an underestimation of the real calcium hydroxide content by thermal analysis. The solvent exchange drying technique is studied for different times of storage in the organic solvent and for cement pastes of different ages. TGA and DSC graphs of these pastes are compared with pastes vacuum dried at 2.5×10-2 mbar.

Keywords: Cement, hydration, solvent exchange, vacuum drying, thermal analysis

Online publication: 2006-08-02
Classification: 3.2 Theme 2: From Fresh to Hardened Concrete
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2351580028.067