CEMENT COMPOSITION LOW IN INITIAL HYDRATION CALORIFIC VALUE

摘要

PPROBLEM TO BE SOLVED: To provide a cement composition low in initial hydration calorific value, in particular having the cement hydration calorific value of 10 J/g or below in 0 to 1 hr after wetting with water measured by a conduction calorimeter. PSOLUTION: The objective cement composition is obtained by developing the composition whose aluminate phase amount and hemihydrate gypsum amount are controlled each within a certain range, based on a finding that in the composition having the hemihydrate gypsum amount within a specific range, there is an extremely favorable correlation between the hydration calorific value and the aluminate phase amount quantified by the Rietveld analysis method utilizing a powder X-ray diffraction. In particular, the cement composition having the aluminate phase amount by the above method of 8 mass% or less and the hemihydrate gypsum amount of 1.5-4 mass% is preferably low in initial hydration calorific value. PCOPYRIGHT: (C)2004,JPO