Funded by a 1998 Preservation Technology and Training Grant, the Standard Practice for Determining the
Components of Historic Cementitious Materials is a series of recommended methods for the analysis of historic
mortars. Scholars, conservators, and preservationists, among others, are interested in the composition of
historic mortars for a number of reasons. Scholars interested in changes in technology may focus on the
types of additives and improvements in working properties of cement-based mortars. Conservators and
preservationists may be interested in identifying and recommending mortars to repair or replace historic
mortars. They may be interested in the way in which historic mortars have weathered over time. They are
interested in identifying aggregates and binders, looking at mineralogy, or studying failures of materials caused
by decay mechanisms.
This report presents a review of the literature followed by recommendations based on best practices for the
analysis of historic cement-based materials. The report is geared towards the practicing analyst. Test methods
described with the report are for the identification of aggregate additives, cement material, pozzolana, and
hydraulic materials in historic mortars. Air voids are also characterized. Test methods described include
wet chemical analysis, thin-section petrographic analysis coupled with image analysis, scanning electron
microscopy, and X-ray diffraction. Clays or organic materials are identified by Fourier Transform Infrared
Spectroscopy.
Reviewed by Dr. Mary Striegel, NCPTT Materials Research Program Manager