Title
Self healing phenomena in concretes and masonry mortars: A microscopic study
Author
Nijland, T.G.
Larbi, J.A.
van Hees, R.P.J.
Lubelli, B.A.
de Rooij, M.R.
TNO Bouw
Publication year
2007
Abstract
A microscopic survey of over 1000 of samples of concrete and masonry mortars from structures in the Netherlands shows that, in practice, self healing occurs in historic lime and lime – puzzolana mortars, in contrast to modern cement bound concretes and mortars. Self healing may be effected by the formation of either new Ca-carbonate, CaCO3, or portlandite, Ca(OH)2. The latter may represent a precursor stage to final self healing producing CaCO3, which has a larger molar volume than portlandite; transition from the possibly initially formed CaCO3-polymorph vaterite will, however, involve a slight decrease in volume. In the paper, compositions and external conditions of samples clearly showing self healing will be evaluated. In addition, it is discussed whether the observed self healing phenomena should be desired, i.e. whether internal mass transfer in the material resulting in the healing does not imply weakening of deeper zones of the material.
Subject
Buildings and Infrastructure
Materials
Built Environment
To reference this document use:
http://resolver.tudelft.nl/uuid:b306c0e7-f788-4dbf-8bdf-0f328031fc0a
TNO identifier
331250
Source
Proceedings of the First International conference on Self Healing Materials 18-20 April, 2007, Noordwijk aan Zee, 9
Document type
conference paper