Concrete deterioration and floor heave due to biogeochemical weathering of underlying shale

Download
  1. (PDF, 3 MB)
  2. Get@NRC: Concrete deterioration and floor heave due to biogeochemical weathering of underlying shale (Opens in a new window)
AuthorSearch for: ; Search for:
TypeArticle
Journal titleCanadian Geotechnical Journal
ISSN0008-3674
Volume12
Issue3
Pages372378; # of pages: 7
Subjectheave; floors; concrete (materials); shale; weathering; gypsum; Concrete; soulevement; plancher; beton (materiau); schiste; action des intemperies; gypse
AbstractWhen the basement floor of a church in the New Edinburgh area of Ottawa heaved, it was discovered that the concrete under the floor had been reduced to a mushy consistency due to attack by sulfate solution formed by the oxidation of pyrite in the underlying shale. Gypsum was the main product in the weathered zone of the shale. It is shown that heaving resulted from the growth of gypsum crystals between the lamellae in the shale. Jarosite, which is formed by a series of oxidation reactions from pyrite, was also found in the weathered shale. Some oxidation reactions occur only in the presence of sulfur bacteria. The cementitious portion of the concrete was leached out by acid, leaving a weak porous material. The importance of safeguarding concrete in contact with potentially expansive shales from sulfate attack is emphasized.
Publication date
LanguageEnglish
AffiliationNRC Institute for Research in Construction; National Research Council Canada
Peer reviewedYes
IdentifierDBR-RP-646
NRC number14798
2770
NPARC number20373986
Export citationExport as RIS
Report a correctionReport a correction
Record identifier227ea43d-85f6-4406-b918-edd0fde36580
Record created2012-07-23
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)