Back to Search
Start Over
Computed X-ray Tomography Study of Carbonate Precipitation in Large Portland Cement Pores
- Source :
- Crystal Growth & Design, 19 (10), Crystal Growth & Design
- Publication Year :
- 2019
- Publisher :
- American Chemical Society (ACS), 2019.
-
Abstract
- Cement degradation caused by CO2 exposure is an increasingly important environmental challenge that must be understood, for example, if former oil reservoirs are to be used for CO2 storage. When exposed to CO2-saturated brine, cement undergoes a chemically complex carbonation process that influences all the physicochemical properties of the cement. It is known that under favorable conditions, fractures and voids in cement can be occluded, or self-sealed, by precipitation of calcium carbonate. Here, we report a detailed X-ray microcomputed tomography (μ-CT) study on the carbonation of gas pores (macropores) of diameter ∼1 mm in cement. Specifically, cured class G Portland cement with sub-millimeter spherical disconnected macropores was exposed to CO2-saturated brine at high pressure (280 bar) and high temperature (90 °C) for 1 week. High-resolution synchrotron-based μ-CT enabled visualizing the morphology of the precipitates inside the macropores within both unreacted and carbonated regions. Quantitative analysis of the type and amount of material deposited in the macropores during carbonation suggests that the filling of the disconnected macropores involves transport of calcium ions from the cement bulk to the macropore interior. A detailed model describing the chemical processes involved is provided. The present study gives a deeper understanding of cement carbonation by literally shedding light on the complex precipitate structures within the macropores.<br />Crystal Growth & Design, 19 (10)<br />ISSN:1528-7483<br />ISSN:1528-7505
- Subjects :
- Ions
Cement
Materials science
010405 organic chemistry
Precipitation (chemistry)
Metallurgy
General Chemistry
Co2 storage
010402 general chemistry
Condensed Matter Physics
01 natural sciences
Depositions
0104 chemical sciences
law.invention
chemistry.chemical_compound
Portland cement
Computed x-ray tomography
chemistry
law
Carbonate
Degradation (geology)
Calcium
General Materials Science
Subjects
Details
- ISSN :
- 15287505, 15287483, and 58505857
- Volume :
- 19
- Database :
- OpenAIRE
- Journal :
- Crystal Growth & Design
- Accession number :
- edsair.doi.dedup.....c8831c9aaddccbc20055480f2ecd3ac5