Approximate proportion requirements for mortar-cement mortar are given in Table 2.6. The proportions given in that table are near the midpoints of the ranges of proportions required by ASTM C270. When specifying a mortar by the proportion specifications of ASTM C270, it is not necessary to specify the proportions, only the mortar type. By far the most common types are single-bag mixes (the first four lines of the table). Types M and S mortar-cement mortar can also be made, however, by adding portland cement to Type N mortar cement. Property requirements for mortar-cement mortar from ASTM C270 are repeated in Table 2.7.
