prBAS EN 196-12:2026

This document specifies two equivalent test methods to assess the chemical reactivity of a pozzolanic or latent hydraulic cement constituent or concrete addition by measurements of heat of hydration (see Clause 5 and 8.3 Method A, Heat of Hydration) or bound water content (see Clause 5 and 8.4 Method B, Bound Water Content) of hydrated pastes composed of the cement constituent or concrete addition, calcium hydroxide, calcium carbonate, potassium sulfate, and potassium hydroxide cured at 40 °C for 72 h and 168 h (3 days and 7 days). These two test methods measure chemical reactivity of test specimens intended for use as cementitious materials, such as cement constituents and concrete additions. The test methods do not distinguish between latent hydraulic and pozzolanic reactivity. The test methods are used for qualification purposes if the cement constituents or concrete additions are tested at the fineness as specified by the respective product standards. In the absence of a product standard or a specification in the product standard, the constituents are tested at the fineness of the intended use. NOTE In case the test methods are used for purposes of comparison of intrinsic reactivity, cement constituents are tested at similar fineness, where possible. The test methods are also used for testing other new constituents that are latent hydraulic or pozzolanic and that are not covered by EN 197 series product standards. However, for such new constituents the validity of the underlying correlations with strength development have not been verified; in consequence the test results can only be used for informative and indicative purposes. Furthermore, these test methods are used in manufacturing control of cement constituents for assessing their latent hydraulic or pozzolanic reactivity.