Measurement Methods of Carbonation Profiles in Concrete: Thermogravimetry, Chemical Analysis and Gammadensimetry
This paper deals with 2 experimental methods to determine carbonation profiles in concrete. Gammadensimetry is a non-destructive test method able to measure the total penetrated CO2 and monitor the carbonation process during laboratory accelerated tests. The second method is thermogravimetric analysis (TGA) supplemented with chemical analysis (CA): as TGA is performed on a small mortar sample not representative of the whole tested concrete, CA is needed to proportion the sample cement content, the sand content, and to correct the TGA results becoming thus representative of the concrete mix. Consequently, TGA-CA gives accurate quantitative profiles in carbonated cementitious materials. Results are reported for an ordinary Portland cement paste, and 3 concrete mixes, containing siliceous or calcareous aggregates. The CO2 mass loss due to carbonation occurs from 530-950°C, which overlaps the temperature range of the calcareous aggregate dissociation. To solve the problem, the origin of CaCO3 is carefully analyzed. Calcium carbonate ensuing from C–S–H carbonation dissociates in a lower temperature range than the more stable one ensuing from portlandite carbonation and from limestone, which enables C–S–H carbonation to be distinguished from calcareous aggregates. Therefore, TGA-CA allows the CaCO3 ensuing from C–S–H carbonation to be measured and to calculate the portlandite degraded by carbonation. Thus, the total calcium carbonates profiles can be deduced even when calcareous aggregates is present in the concrete mix.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/00088846
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Supplemental Notes:
- Abstract reprinted with permission from Elsevier
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Authors:
- Villain, Geraldine
- Thiery, M
- Platret, Gerard
- Publication Date: 2007-8
Language
- English
Media Info
- Media Type: Print
- Features: Figures; References; Tables;
- Pagination: pp 1182-1192
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Serial:
- Cement and Concrete Research
- Volume: 37
- Issue Number: 8
- Publisher: Elsevier
- ISSN: 0008-8846
- Serial URL: http://www.sciencedirect.com/science/journal/00088846
Subject/Index Terms
- TRT Terms: Carbonation; Concrete construction; Concrete structures; Nondestructive tests; Reinforced concrete; Reinforcing steel; Structural analysis; Thermal analysis; Thermogravimetric analysis
- Uncontrolled Terms: Calcium silicate hydrate; Gammadensimetry
- Subject Areas: Highways; Materials; I32: Concrete;
Filing Info
- Accession Number: 01076969
- Record Type: Publication
- Files: TRIS
- Created Date: Sep 27 2007 7:07AM