THERMOANALYTICAL EVENTS AND ENTHALPIES OF SELECTED PHASES AND SYSTEMS OF THE CHEMISTRY AND TECHNOLOGY OF CONCRETE - PART 1. CALCIUM-SILICATE-ALUMINATE-SULFATE HYDRATES

摘要

Essential focus of the study has been to acquire thermoanalytical events, incl. enthalpies of decompositions - ?H, of naturalminerals of calcium-silicate-sulfate-aluminate hydrates. The thermoanalytical curves of thaumasite and ettringite arefully in line with that reported in reference sources. The values of ?H calculated from DSC curves in the intervals of keydecomposition steps ranging from 50 to 250 ~(o)C, achieve (1215 +/- 60) J g~(-1) for thaumasite and (930 +/- 40) J g~(-1) for ettringite.The differing values of decomposition enthalpies ?H, as presented by various research groups, are indicated and criticallydiscussed in the paper.