Porosity and Specific Surface Area of Roman Cement Pastes

Mercury porosimetry, water vapor, and nitrogen adsorption were used to follow the hydration of Roman cements--belite cements calcined at low temperature. Generally, unimodal distribution of pore sizes was observed, with the threshold pore width decreasing considerably with increasing curing time. An open porous structure with the threshold pore diameter between 0.2 and 0.8 μm and the specific surface area not exceeding 20 m²/g was produced at early ages when quick growth of the C-A-H phases is observed. The surface area reached up to 120 m²/g and the threshold pore width shifted to about 0.02 μm when subsequent formation of C-S-H gel filled the larger pores. Both mercury porosimetry and water vapor adsorption were found to be capable of following the progress of hydration of the Roman cements with high reliability at least for a comparative evaluation of historic Roman cement mortars and repair materials used in restoration projects.

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  • English

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  • Accession Number: 01144419
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 26 2009 7:20AM