Determination of isothermal unsaturated capillary flow in high-performance cement mortars by NMR imaging

Title: Determination of isothermal unsaturated capillary flow in high-performance cement mortars by NMR imaging
Author(s): K. Hazrati, L. Pel, J. Marchand, M. Pigeon
Paper category : journal
Serial title: Concrete Science and Engineering
Abreviated Serial title: Concr. Sc. Eng.
ISSN: 1295-2826
Publisher: RILEM Publications SARL
Volume: 4
Issue: 16
Issue date: 2002-12-01
Publication year: 2002
Pages: 614 - 622
Total Pages: 9
Nb references: 35
Language: English

Abstract: The time-dependent liquid water distribution in
cement mortar mixtures during water absorption was
determined using a proton nuclear magnetic resonance
imaging (NMRI)technique.The variation of the material
water diffusion coefficient with the water content was
established on the basis of these results.Eight different
mortar mixtures were prepared and tested.Test variables
included water/binder ratio (0.60,0.40 and 0.25),type of
cement (an ASTM Type 1 cement and a commercial
white cement)and the use of silica fume.In addition,the
effect of drying treatments on the water transport proper-
ties was also investigated.The absorption of water in dry
mortars is found to be well described by a non-linear dif-
fusion equation based on the extended Darcy's law of con-
tinuum mechanics.Results also confirm that the macro-
scopic water diffusion coefficient (D(thêta)) of mortar is
strongly dependent on the material water content.The
relationship between the two parameters can be modeled
by two exponential equations.Test results finally show
that a reduction of the mortar water/binder ratio and the
use of silica fume tend to significantly decrease the
absorption of water.This phenomenon is well described
by the water penetration coefficient (lambda)max(.)

Online publication: 2002-10-30
Classification: Scientific Reports
Publication type : full_text
Public price (Euros): 0.00