PROBLEM TO BE SOLVED: To enable the sure evaluation of the compressive strength of the mortar according to the tendency of long-term strength manifestation for every fly ash as an admixture material for concrete, as well as capable of extremely shorten the formation of a test body for determining the pozzolanic reactivity and capable of shortening the aging term in the determination of the pozzolanic reactivity of the fly ash. SOLUTION: The determination of the pozzolanic reactivity of the fly ash is composed of a step (S1) of estimating the regression line of the correlation between the pozzolanic activity estimation index and the mortar activity index by aging term by the fly ash type, a step (S2) of obtaining the pozzolanic activity evaluation index regarding the fly ash for determining a mortar activity index, and a step (S3) of obtaining the mortar activity index by the aging term by substituting the pozzolanic activity evaluation index of the fly ash being the determination object into the regression line of the fly ash type determined from the attribute of the fly ash of the determination object. COPYRIGHT: (C)2009,JPO&INPIT
