ASTM C207-91(1997)

1.1 This specification covers four types of hydrated lime. Types N and S are suitable for use in mortar, in scratch and brown coats of cement plaster, for stucco, and for addition to portland-cement concrete. Types NA and SA are air-entrained hydrated limes that are suitable for use in any of the above uses where the inherent properties of lime and air-entrainment are desired. The four types of lime sold under this specification shall be designated as follows:

1.1.1 Type N- Normal hydrated lime for masonry purposes.

1.1.2 Type S- Special hydrated lime for masonry purposes.

1.1.3 Type NA- Normal air-entraining hydrated lime for masonry purposes.

1.1.4 Type SA- Special air-entraining hydrated lime for masonry purposes.

Note 1-Type S, special hydrated lime, and Type SA, special air-entraining hydrated lime, are differentiated from Type N, normal hydrated lime, and Type NA, normal air-entraining hydrated lime, principally by their ability to develop high, early plasticity and higher water retentively, and by a limitation on their unhydrated oxide content. Note 2-For normal (Type N) and special (Type S) finishing hydrated lime, refer to Specification C206. Note 3-Some building codes prohibit the use of air-entraining materials in mortar, because of the accompanying reduction in bond and compressive strength. Where increased freeze-thaw resistance is important, air-entraining may be beneficial. Air-entraining lime should not be used as a finishing lime.