DELAYED ETTRINGITE FORMATION SYMPTOMS ON MORTARS INDUCED BY HIGH TEMPERATURE DUE TO CEMENT HEAT OF HYDRATION OR LATE THERMAL CYCLE

This article considers the problem of delayed ettringite formation (DEF) symptoms induced by high temperature due to cement heat of hydration or late thermal cycle. The authors note that, previously, DEF cases have mainly been detected on mortars or precast concretes steam-cured according to a predefined temperature cycle during hydration. They report on their study in which mortar bars were made with three different cements (types 10, 20M, and 30). As a first heat treatment, the mortar bars were steam-cured to reproduce the temperature cycle they would undergo if they were at the center of a large mortar member. These specimens were studied for 1 year. After 1 year, half of the specimens were steam-cured for 1 month at 85 deg C. Both groups were then followed for two more years. The early-age steam-cure induced expansions for mortar types 10 and 30. Late steam-curing induced expansions for all three cements tested. In one case (cement type 20M), the early-age steam cure has suppressed or delayed the expansion induced by the late steam cure. Electron microscopy showed that typical DEF symptoms are associated with the expansions. The authors stress that no such results have been reported before and they conclude that DEF is not a phenomenon only related to a high temperature during hydration.

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• Corporate Authors:

  Elsevier

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• Authors:
  • Barbarulo, R
  • Peycelon, H
  • Prene, S
  • Marchand, J
• Publication Date: 2005-1

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 125-131
• Serial:
  • Cement and Concrete Research
  • Volume: 35
  • Issue Number: 1
  • Publisher: Elsevier
  • ISSN: 0008-8846
  • Serial URL: http://www.sciencedirect.com/science/journal/00088846

Subject/Index Terms

• TRT Terms: Cement; Concrete curing; Electron microscopy; Ettringite; Hydration; Mortar; Steam curing; Thermal expansion
• Uncontrolled Terms: Delayed ettringite formation
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00988990
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 18 2005 12:00AM