M G MARGALHA(1), M R VEIGA(2) and J DE BRITO(3)
(1) Municipality of Beja (CMB), University of Évora (UE)
(2) Laboratório Nacional de Engenharia Civil (LNEC)
(3) Instituto Superior Técnico (IST)
Until the 19th century, lime in construction renderings was used mostly as a paste. After the transformation of rock into lime, the latter was stored in such a way as to maintain its characteristics. For that purpose, tanks or big ditches were used to store lime, always covered by water to avoid its carbonation.
Through this procedure, the quality of the material was guaranteed for many years.
The evolution that occurred in the material’s storing processes led to a change in this procedure, i.e. the binders being used today are in most cases powdery mixtures.
Lime slaking is done at the factory, with the necessary care to avoid its contact with carbon dioxide from the atmosphere, which is not always achieved until its application in the work.
In the present paper, the authors present some results concerning the mechanical behaviour of mortars made with lime putties with different maturation times. The authors also make an analysis of the microstructure of these limes putties and of each one of the mortars prepared with these materials, during the fresh phase and, later, in the hardening phase.