This test method provides procedures for petrographic examination and chemical analysis of mortar for components of masonry mortar. These components may include portland cement, hydrated calcitic or dolomitic lime, masonry cement, aggregates, and air.

The test method consists of procedures and sub-procedures, each requiring a substantial degree of petrographic and chemical skills and relatively elaborate instrumentation.

The chemical data considered together with results of petrographic examination of a mortar provide for calculation of component proportions and thus allow a determination of mortar composition as represented by Types M, N, S, and O in Table 1 (Proportion Specification Requirements) of Specification C270.

Failure of a mortar to have the composition of any type as defined in Table 1 of Specification C270 does not necessarily mean that the mortar does not meet the requirements of Specification C270. The mortar may meet the alternative requirements of Table 2 (Property Specification Requirements) of Specification C270.

The maleic acid method of analysis is not applicable for the analysis of mortar because it is greatly influenced by carbonation and does not provide for the determination of calcium.