Effects of Carbonation on the Specific Surface BET of Cement Mortar Measured by Two Different Methods: Nitrogen Adsorption and Water Adsorption

Abstract:

The objective of this work was to examine the microstructural changes caused by the carbonation of normal mortar. Samples were prepared and subjected to accelerated carbonation at 20°C, 65% relative humidity and 20% CO₂ concentration. The evolutions of the pore size distribution and the specific surface area during carbonation were calculated from the adsorption - desorption isotherms of water vapour and nitrogen. Conflicts observed in the results showed that the porous domains explored by these two methods are not the same due to the difference in molecular sizes of nitrogen and water. These two techniques therefore help to complementarily evaluate the effects of carbonation. The study also helped to explain why results in the literature diverge greatly on the influence of carbonation on specific surface area.

• Periodical: Advanced Materials Research (Volumes 931-932)
• Pages: 421-425
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.931-932.421
• Online since: May 2014
• Authors: Son Tung Pham*, William Prince
• Keywords: Carbonation, Nitrogen Adsorption, Specific Surface BET, Water Adsorption

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