The new standard (soon to be published as C1753, Practice for Evaluating Early Hydration of Hydraulic Cementitious Mixtures Using Thermal Measurements) describes the apparatus and procedure for such evaluations. This will help with efforts such as screening materials and proportions without having to spend time and money on trial mixtures.
“Concrete and other cementitious mixtures continue to become more complex, with more supplementary cementitious materials and chemical admixtures coming to market,” says ASTM member Tim Cost, senior technical service engineer, Holcim US Inc. “Performance effects on concrete and other mixtures become more difficult to predict as specific components and proportions change.”
The standard covers many applications, including evaluation of setting properties and the relative effects of different materials on setting; checks on potential incompatibility of materials; screening of materials for optimum performance; development of optimum proportions; and selection of admixture dosage.
Cost notes that the test described in the new standard is expedient and requires small time and equipment commitments compared to other approaches.
In addition to suppliers and manufacturers, testing laboratories and researchers will be primary users of the standard.