Table 11. Air content in fresh concrete.
Antifreeze
Curing
admixture
temperature
Fresh
Mix
and dosage
WRDA-19
Daravair
Slump
air
concrete
(C)
(g/kg)†
(g/kg)†
no.
(% s/s)*
(cm)
(%)
1A
Control (no anti-
freeze admixture)
5.0
0.8
13
22
6.0
2A
PolarSet, 6%
7.8
0.6
17
7
6.6
3A
DPTC, 6%
7.6
0.6
17
7
5.9
4A
DP, 6%
7.5
0.7
17
7
5.8
5A
PolarSet, 8%
8.1
0.6
13
7
6.0
6A
DPTC, 8%
4.4
0.5
13
7
5.6
7A
DP, 8%
8.1
0.6
16
7
5.9
1B
Control (no anti-
freeze admixture)
5.0
0.8
15
22
5.9
2B
PolarSet, 6%
7.7
0.8
15
7
6.9
3B
DPTC, 6%
9.2
0.9
13
7
5.3
4B
DP, 6%
9.2
0.7
5.75
7
5.5
5B
PolarSet, 8%
10.2
1.1
15
7
6.2
6B
DPTC, 8%
10.2
1.2
13
7
6.7
7B
DP, 8%
10.2
1.2
14
7
7.0
* % s/s = Percent of weight of the solids in the antifreeze admixture by weight of cement.
† g/kg = Amount of admixture in grams of admixture per kilogram of cement.
1) Fresh concrete air content. The air content of
ACI 201 Guide to Durable Concrete and ASTM C
each mix was measured within eight minutes from
457 recommend that the total air content be be-
the end of the mixing. Table 11 shows that the
tween 4.5% and 7.5%, and that the specific surface
target air content and slump were achieved with
be greater than 24 (1/mm), and that the average
spacing factor be 200 m or less. The test results
and without the antifreeze admixtures. Therefore,
these admixtures are compatible with the water
indicate that mixtures 1 and 2 meet the required
reducer and the air entraining admixtures tested,
air content. Mixture 3 is only slightly short of
and caused no detrimental effect.
meeting the minimum air content, while mixture
2) Hardened concrete air content. The total air
4 had an excess of air voids. Too much air con-
content and parameters of the air-void systems
tent may weaken the strength of concrete. The
were measured on concrete slabs, which were cut
total air content in mixture 3 is slightly (0.1%)
from the center of cylinders cast from each of the
below the recommended minimum value for
previously described mixtures. Each cylinder size
durable concrete. However, its spacing factor is
was 7.6 cm 15.2 cm. The cylinder numbers cor-
favorable, which indicates an abundance of very
respond to the individual mixture identification,
small voids that may provide adequate freeze
disregarding whether they came from groups A
thaw protection.
or B. Only the first four mixtures listed in Table 11
The total air content and average void spacing
were analyzed. As indicated in that table, mixture
factor are the most important parameters for
1 represents a control concrete with a super plasti-
gauging the freezethaw durability of hardened
cizer and an air-entraining admixture, but with
concrete. The use of antifreeze admixtures does
no antifreeze admixture. Mixture 2 con-
tains the same ingredients as mixture
1, except for the commercial low-tem-
Table 12. Air-void parameters in concrete containing antifreeze
admixtures.
perature admixture PolarSet dosed at
6% of solids by weight of portland ce-
Air-void parameters
Mixture 1
Mixture 2 Mixture 3 Mixture 4
ment. Similarly, mixture 3 contains the
Air content (%)
5.5
7.5
4.4
8.5
selected antifreeze admixture DPTC at
Chord length (m)
124
135
109
152
6% dosage. Mixture 4 contains the se-
Voids per cm
4.3
5.5
3.9
5.5
lected antifreeze admixture DP. The air
Specific surface (1/mm)
31.9
29.8
36.9
26.1
Spacing factor (m)
contents and other air-void parameters
152
137
145
140
Paste content (%)
30.7
30.7
30.7
30.7
are summarized in Table 12.
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