ASTM C 91 - 05 Standard Specification for Masonry Cement

American Society for Testing and Materials (ASTM). Current edition approved September 15. 2005. Published October 2005. Originally approved in 1932. Last previous edition approved in 2003 as C 91-03a. 4 p. This specification covers three types of masonry cement for use where mortar for masonry is required.
The values stated in SI units are to be regarded as the standard. Values in SI units shall be obtained by measurement in SI units or by appropriate conversion of measurements made in other units, using the Rules for Conversion and Rounding given in IEEE/ASTM SI 10.