This method covers the determination of early stiffening in hydraulic cement mortar. The values stated in SI units are the standard. The values in parentheses are for information only. This standard does not purport to address all of the safety concerns@ if any@ associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Warning??Fresh hydraulic-cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure. The use of gloves@ protective clothing@ and eye protection is recommended. Wash contact area with copious amounts of water after contact. Wash eyes for a minimum of 15 minutes. Avoid exposure of the body to clothing saturated with the liquid phase of the unhardened material. Remove contaminated clothing immediately after exposure. The text of this standard references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.