Table 15. Mixture proportions per cubic meter, New Hampshire.
derived from previous laboratory data. As can be
Table 16. Properties of fresh concrete, New
seen, all field samples performed well. They ex-
ceeded minimum strength requirements. In addi-
tion, the concrete was estimated to have attained
at least 12 MPa before it reached 5C. The con-
crete was able to resist freezing at that strength,
shown by the fact that no ice damage was de-
tected in core samples removed from the bin in
tion between the cement and water
had been completed by then.
The slab reached a mostly uniform
temperature within 18 hours. The
wall achieved uniform temperature
almost immediately. The wall, hav-
ing two surfaces exposed to the am-
bient air, was most easily affected
by surrounding air.
The concrete was transported by
rotary-drum truck from a ready-mix
plant 16 kilometers from CRREL. The
concrete was mixed using unheated
aggregate with heated water (82C).
Concrete Age (days)
The ingredients were added into the Figure 4. Compressive strength of pullout cylinders from wall-slab
truck's drum, mixed a few minutes, prototype.
and then transported 1520 minutes
FIELD APPLICATION OF
given in Table 15. The truck took about 15 min-
utes to discharge its load, and finishing opera-
tions took another 30 minutes. Table 16 gives prop-
Soo Locks slabs
erties of each mixture as delivered to the site.
Results of the strength tests from the field-cured
pullout cylinders taken out of each concrete sec-
To demonstrate the practicality of using anti-
tion are presented in Figure 4. The target slump
freeze admixtures under field conditions.
was 10 cm.
Control, admixture-free concrete was not mixed
during this experiment. The control curves in-
Three on-grade slabs were cast. One slab was
cluded in Figure 4 correspond to concrete of simi-
made of admixture-free concrete to act as a con-
lar mix proportions made with aggregates and
trol. It was protected with a heated shelter. A sec-
cement from the same sources. These values were
ond slab was made with concrete containing the