The authors of this paper use mechanical-shear and electromagnetic waves to monitor the setting and hardening of cement, bentonite-cement slurries, and attapulgite-cement slurries. The test specimens are prepared by prehydrating the clay before adding cement. The presence of clays in soil-cement slurries delays hydration and its manifestation. The complex permittivity emerges as a sensitive gauge to ongoing reactions. Permittivity reflects changes in the mobility of water, liberation and entrapment of ions, changes in specific surface, and variations in double-layer phenomena. The rise in shear-wave velocity mirrors the increase in effective stress due to consolidation, the decrease in double-layer repulsion, and the higher rigidity of the mixture as a result of cementation. Initial phases of hydration denoted by changes in permittivity do not add to the formation of a rigid, cemented network. Overall, it is revealed that the simultaneous measurement of permittivity and shear-wave velocity provides complementary microlevel information on the basic dependency between chemical reactions, physical changes, and rigidity in cementitious materials. The application of these results in the field will lead to the development of nonintrusive, nondestructive monitoring procedures.


  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: p. 365-373
  • Serial:

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Filing Info

  • Accession Number: 00720460
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 29 1996 12:00AM