ASTM C1897-20

5.1 These test methods are used to assess the chemical (pozzolanic or hydraulic) reactivity of SCMs over a curing time of 7 days. The results of these test methods can be used to estimate the potential contribution of a SCM to the development of strength, or other properties such as lower permeability, when used with portland cement. However, the test results are not a substitute for direct measurement of the same properties of concrete made with that SCM.

5.2 The calcium hydroxide, calcium carbonate, potassium sulfate, and potassium hydroxide are combined in proportions to provide a paste where the dissolved ions from these components simulate the pore solution in a portland cement system.

5.3 The pastes are cured at 40 °C to accelerate the rate of reaction of slowly reactive SCMs.

5.4 These test methods allow for the direct measurement of the hydraulic or pozzolanic reactivity of a potential SCM. These test methods are also suitable for screening purposes in the development and research of SCMs for use in portland cement-based systems. Furthermore, these test methods may be used in manufacturing control of portland cement-based products for assessing the hydraulic or pozzolanic reactivity of a SCM component.

5.5 These test methods are based on the work by Avet et al.5.6 There is no requirement to use Method A and Method B for a given application. In many instances the choice is based on the user’s determination of available equipment. Method A can also provide an indication of rate of reactivity because measurements are taken continuously during the test period, while Method B provides the level of reactivity up to a single point in time.

1.1 These two alternative test methods are used to assess the chemical reactivity of a supplementary cementitious material (SCM) as determined by measurements of cumulative heat release or bound water content of hydrated pastes composed of the SCM, calcium hydroxide, calcium carbonate, potassium sulfate, and potassium hydroxide cured at 40 °C for 3 and 7 days.

1.2 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.

1.3 The text of the standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard.

1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.