Mortar analysis helps in the matching of new mortar for conservation and restoration work with the old. The analysis is carried out to ascertain the structure and ingredients of samples of historic mortar. It also provides and objective description, for instance for archaeological recording work. A typical mortar analysis consists of disaggregation with mild acid and filtration of a given sample, followed by optical examination and sieve analysis, expressing the amounts of sands and fines as a percentage of the whole, followed by the production of a pro forma report.
Matching old mortars
Old mortars can be matched by using the right kinds of aggregate (sands, stone dusts, etc.), the right kinds of binder (lime putty, hydraulic limes, cements, etc.), and by matching the application and finish of the original.