An assessment of the relative permeability of cement systems using AC impedance techniques

Citation
Z. Liu et Jj. Beaudoin, An assessment of the relative permeability of cement systems using AC impedance techniques, CEM CONCR R, 29(7), 1999, pp. 1085-1090
Citations number
11
Categorie Soggetti
Material Science & Engineering
Journal title
CEMENT AND CONCRETE RESEARCH
ISSN journal
00088846 → ACNP
Volume
29
Issue
7
Year of publication
1999
Pages
1085 - 1090
Database
ISI
SICI code
0008-8846(199907)29:7<1085:AAOTRP>2.0.ZU;2-I
Abstract
Aspects of the rapid chloride permeability test (AASHTO T277/ASTM C1202) we re investigated using the AC impedance technique. Permeability and impedanc e measurements were performed at different ages on the various cement paste s prepared with or without silica fume and/or superplasticizer. The elastic modulus of the pastes was also determined. The addition of silica fume and /or superplasticizer had no significant effect on the elastic modulus of th e pastes at the same water/cement ratio. The addition of silica fume signif icantly in creased the impedance and decreased the total charge passed (tot al coulombs) irrespective of the actual chloride penetration. The naphthale ne sulfonate-type of superplasticizer had no significant impact on the impe dance, and the total charge passed. Linear relationships between the impeda nce, total coulombs, and initial current were observed. It is apparent that the impedance is an equivalent indication of the relative permeability and the total charge passed. Therefore, it appears possible to develop a new s imple and rapid method to assess the relative permeability of the cement sy stems using the AC impedance technique. (C) 1999 Elsevier Science Ltd. All rights reserved.