Table 21. Equivalent insulation test results.
Compressive strength--MPa (psi)
Table 20. Durability factors for Pozzutec 20 and
Mixture ID
7 days
14 days
28 days
EY-11 concrete.
3,0,10 (control)
27.9 (4052)
39.8 (5767)
43.8 (6348)
3,2,5
32.4 (4691)
36.7 (5326)
39.8 (5771)
Dosage
3,2,2
30.6 (4439)
32.3 (4685)
35.3 (5112)
60 (90)
100 (150)
3,2,2
26.5 (3846)
35.7 (5170)
38.2 (5543)
Admixture
None
mL/kg (fl oz/cwt)
mL/kg (fl oz/cwt)
3,3,5
33.0 (4778)
36.9 (5349)
42.1 (6098)
Control
99
3,3,2
30.8 (4465)
34.1 (4941)
35.8 (5190)
Pozzutec 20
99
Failed
3,3,2
26.3 (3817)
34.3 (4970)
38.8 (5628)
EY-11
98
96
Table 22. Equivalent insulation values for 152-mm- (6 in.)
thick wall maintained at 10C (50F) for seven days.
Air temperature Required thermal resistance Equivalent fibrous
C (F)
m2 K/W (hr ft2 F/Btu)
Mixture
glass--mm (in.)
3,2
1 (30.2)
1.1 (6.5)
50 (2.0)
3,3
1 (30.2)
1.1 (6.5)
50 (2.0)
present. It appears that the higher dosages of these
PHASE IV: FIELD APPLICATION
admixtures may decrease the chloride threshold.
Procedure
Task 3: Durability
The objective of Phase IV was to validate the
The freezethaw durability of concrete made
EY-11 admixture developed in Phase III by means
with Pozzutec 20 and EY-11 was tested using
of a field trial. Special attention was given to work-
ASTM C 666, Procedure A, and evaluated accord-
ability, finishability, temperature records, and
ing to ASTM C 494. Table 20 shows the results. As
strength development.
happened in Phase I, Pozzutec 20 passed the du-
The prototype admixture (EY-11) was tested
rability test at a dosage of 60 mL/kg (90 fl oz/
outdoors at CRREL, Hanover, New Hampshire,
cwt) but not at 100 mL/kg (150 fl oz/cwt). EY-11,
and at the Corps of Engineers Soo Locks, Sault
on the other hand, showed very high durability at
Ste. Marie, Michigan, during February and March
both dosages.
1994. The CRREL site was chosen because of its
proximity to testing facilities and because it pro-
Task 4: Equivalent insulation
vided a location convenient for long-term moni-
The purpose of this task was to determine the
toring of the concrete. The Soo Locks was attrac-
amount of insulation that EY-11 can replace in a
tive because it provided an opportunity to
420 kg/m3 (705 lb/yd3) cement factor mix. Table
compare normal winter concreting to concreting
21 presents the strength results at various low
with antifreeze admixtures. The timing at each
temperatures. Since EY-11 does not enhance the
site was determined from weather records and
late age strength of concrete (Phase III, Task 1)
forecasts that promised weather conditions ap-
propriate to the 5C (23F) capability of the ad-
when cured at room temperature, the effect of
EY-11 was evaluated only at the seven-day
mixture. A technical representative from MB was
strength. EY-11 was found to increase compres-
on hand to evaluate the effectiveness of the ad-
sive strength relative to 10C (50F) down to ap-
mixture with the cements used at each site. CRREL
proximately 1C (30F) for both dosages.
personnel provided instrumentation for monitor-
Table 22 shows that EY-11 is equivalent to a
ing temperatures and helped measure properties
of the fresh and hardened concrete. Pozzutec 20
Btu), or about 50 mm (2 in.) of fibrous glass insu-
was used to batch a separate mix of concrete for
lation.
comparison purposes.
17
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