Effects of carbonation on the pore structure of non-hydraulic lime mortars
- Department of Architecture and Civil Engineering, University of Bath, BATH, BA2 7AY (United Kingdom)
- Department of Chemical Engineering, University of Bath, BATH, BA2 7AY (United Kingdom)
The pore structures of carbonated non-hydraulic lime mortars made with a range of different aggregates and concentrations of lime have been determined using mercury intrusion porosimetry (MIP). MIP data have been correlated with scanning electron microscopy images and other porosity data. During carbonation there is an increase in pore volume in the {approx} 0.1 {mu}m pore diameter range across all mortar types which is attributed to the transformation of portlandite to calcite. Also there is a monotonic increase in the volumes of pores with diameters below 0.03 {mu}m. A model is proposed for the changes in pore structure caused by carbonation. This attributes the increase in the volume of sub 0.03 {mu}m pores to the attachment of calcite crystals to the surface of aggregate particles, and in some cases to the surface of portlandite crystals. This phenomenon may explain the continuing presence of portlandite in mortars that, apparently, have fully carbonated.
- OSTI ID:
- 20995395
- Journal Information:
- Cement and Concrete Research, Vol. 37, Issue 7; Other Information: DOI: 10.1016/j.cemconres.2007.04.011; PII: S0008-8846(07)00102-0; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
- Country of Publication:
- United States
- Language:
- English
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