Early strength development and hydration of alkali-activated blast furnaceslag/fly ash blends

Shi, C Day, RL

C. Shi et Rl. Day, Early strength development and hydration of alkali-activated blast furnaceslag/fly ash blends, ADV CEM RES, 11(4), 1999, pp. 189-196

26

INGLESE

Article

Material Science & Engineering

ADVANCES IN CEMENT RESEARCH

0951-7197 → ACNP

11

4

1999

189 - 196

ISI

0951-7197(199910)11:4<189:ESDAHO>2.0.ZU;2-7

This study concerns the effect of two types of fly ash and the addition of lime on the strength development and hydration of sodium hydroxide- and sod ium silicate-activated slag/fly ash blends which consisted of 50% fly ash a nd 50% slag by mass. Performance was compared to that of 100% slag cements. When NaOH was used as an activator, the slag replacement with ASTM Type F fly ash did not show a significant effect on either the strength developmen t or hydration, Type C fly ash did not affect the strength development, but affected the hydration process due to the presence of C(3)A in the fly ash . Both fly ashes had a significant effect on the hydration and strength dev elopment when Na2SiO3 was used as an activator: The addition of a small amo unt of hydrated lime significantly. increased the early-age strength but sl ightly decreased the later-age strength of the activated slag/fly ash blend s. Measurement of the hear evolution during hydration indicated that the ad dition of the hydrated lime had a slight effect on rite hydration during th e pre-induction period, but accelerated the hydration thereafter.