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.