ASTM C1679 − 14 Standard Practice for Measuring Hydration Kinetics of Hydraulic Cementitious Mixtures Using Isothermal Calorimetry

ASTM C1679 − 14 Standard Practice for Measuring Hydration Kinetics of Hydraulic Cementitious Mixtures Using Isothermal Calorimetry

Scope

1.1 This practice describes the apparatus and procedure for measuring relative differences in hydration kinetics

of hydraulic cementitious mixtures, either in paste or mortar (see Note 1), including those containing

admixtures, various supplementary cementitious materials (SCM), and other fine materials by measuring the

thermal power using an isothermal calorimeter.

NOTE 1—Paste specimens are often preferred for mechanistic research when details of individual reaction peaks

are important or for particular calorimetry configurations.

Mortar specimens may give results that have better correlation with concrete setting and early strength

development and are often preferred to evaluate different mixture proportions for concrete.

Both paste and mortar studies have been found to be effective in evaluating concrete field problems due to

incompatibility of materials used in concrete mixtures.

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

this standard.

ASTM C1679 − 14 Standard Practice for Measuring Hydration Kinetics of Hydraulic Cementitious Mixtures Using Isothermal Calorimetry

Significance and Use

5.1 Thermal power curves are used to evaluate the isothermal hydration kinetics of the combined mixture of

different materials during the early period after being mixed with water.

These isothermal power curves, or hydration profiles, may provide indications relative to setting characteristics,

compatibility of different materials, sulfate balance and early strength development.