A Class F fine fly ash (FFA) with a fineness of 99% passing a 45 mu m
sieve was used to produce workable high-strength concrete. Six mixture
s were cast with total cementitious contents of 400 and 500 kg/m(3). T
he replacement of cement by FFA, on equal mass basis, was 0, 10, and 1
5%. The mixtures were tested for workability and strength. Drying shri
nkage and water absorption characteristics were determined as indicati
ve of durability. The slump varied between 45 to 110 mm and fluid/ceme
ntitious ratio varied between 0.25 to 0.38. The optimum cement replace
ment for both 400 and 500 kg total cementitious material mixtures was
10%. The 28-day maximum strength for the two optimum mixtures was 94 a
nd 111 MPa with a slump of 45 and 85 mm, respectively. The indirect te
nsile strength of the two concretes was only 5 and 6% of their compres
sive strength, respectively. The 2 h water penetration of the two conc
retes was comparatively low, II and 13mm, respectively. The drying shr
inkage of all the six concretes were very similar with a maximum value
of 470 microstrain after 56 days of standard exposure. The 28-day mod
ulus of elasticity of all the concretes varied between 40-46 GPa. (C)
1998 Elsevier Science Ltd.