Abstract:
Mortars are among the most important materials in building construction. They are
generally obtained by mixing aggregates with an inorganic binder. The identification of mortar constituents,
particularly the binder type in historic buildings, is one of the essential aspects of building
conservation, considering that the new conservation materials must be chemically, mechanically,
and physically compatible with the old masonries. Among other techniques used to characterise
binders, those related to optical and electronic microscopy are particularly important. Microscopy
and combined techniques may be the key to this identification since the classic mineralogical and
chemical-based identification approaches are not conclusive enough in investigating the types of
hydraulic binders in mortars. This work presents an analysis procedure to identify mortar binders by
combining EDS microanalysis and petrography. Mortar samples of known composition were used
as a reference for analyzing mortars from historic buildings. The proposed methodology made it
possible to identify the type of binder or a mixture of binders based on the identification of the binder
features by petrography together with analysis of the chemical composition of the paste by X-ray
microanalysis under a scanning electron microscope.
