METHOD FOR DETERMINING DELAYED FORMATION OF ETTRINGITE

摘要

PROBLEM TO BE SOLVED: To provide a method for early determining whether there is a risk of occurrence of the delayed formation of ettringite after service by powder X-ray diffraction, in a cured article using a cement composition such as concrete or mortar receiving high-temperature ageing at the initial stage of hydration. SOLUTION: This method determines that DEF does not occur, when the difference between the relative strength of ettringite in the hydrated sample of the cement composition before the reception of high-temperature ageing and that of ettringite in the hydrated sample of the cement composition after the reception of high-temperature ageing is 5% or below. COPYRIGHT: (C)2011,JPO&INPIT