Mechanisms of Radon Exhalation from Hardening Cementitious Materials

The radon exhalation method was used to monitor portland cement hardening. Radon concentration time dependence showed three stages: 1) dormant period, 2) intensive microstructural transformations, and 3) structure densification and drying. When the radon flux starts growing quickly, radon exhalation is especially sensitive to the initial set. A synergy of the following main effects explains the sharp radon flux increase: 1) while porosity is still high, quick microstructural formation, 2) intensive water flow, which traps radon from the newly formed solid C-S-H surfaces to the sample surface and enhances radon emanation power; and 3) high surface evaporation rate, a hydration heat result. Due to the hydration heat, on a solid surface, there is a weakened physical radon gas adsorption that cannot be neglected, although it does not seem to be a decisive mechanism.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/13846872
• Authors:
  • Kovler, Konstantin
• Publication Date: 2008

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References;
• Pagination: pp 404-413
• Serial:
  • ACI Materials Journal
  • Volume: 105
  • Issue Number: 4
  • Publisher: American Concrete Institute (ACI)
  • ISSN: 0889-325X
  • Serial URL: https://www.concrete.org/publications/acimaterialsjournal.aspx

Subject/Index Terms

• TRT Terms: Cement; Concrete hardening; Portland cement; Radon
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 01108939
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 22 2008 8:42AM