MECHANISM FOR PERFORMANCE OF ENERGETICALLY MODIFIED CEMENT VERSUS CORRESPONDING BLENDED CEMENT

Energetically modified cement (EMC) is produced by high intensive grinding/activation of ordinary Portland cement (OPC) together with different types of fillers. This article reports on a study of the microstructure of cement paste of 50/50 mixes of cement/quartz and cement/fly ash, both ground in a special EMC mill process and simply blended. They were then studied under sealed curing conditions. The authors note that the grinding process reduced the size of both cement grains and quartz/fly ash markedly and created flaky agglomerates of high inner surface for the finer particles. Results showed that EMCs had a much higher degree of hydration at 1 day, but similar hydration as blends at 28 days. The pores were much finer for EMC paste due to smaller particles; this was also reflected in the strength. The morphology of calcium hydroxide in EMC paste appeared more mass like. Pozzolanic reaction was insignificant for quartz in EMC, but increased for fly ash. The authors conclude that the improved performance of EMC versus OPC can be explained by increased early hydration and extensive pore size refinement of the hardened binder. The pore size refinement will lead to reduced permeability and diffusivity for EMC concrete.

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    Elsevier

    The Boulevard, Langford Lane
    Kidlington, Oxford  United Kingdom  OX5 1GB
  • Authors:
    • Justnes, H
    • Elfgren, L
    • Ronin, V
  • Publication Date: 2005-2

Language

  • English

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Filing Info

  • Accession Number: 00989029
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 29 2005 12:00AM