Table 1. Mix proportions.
long by 15 cm thick, to the experiment; they were
cast on 15 through 17 March. Inspection and re-
1.9 cm max.
Type 1A
pair of the locks and other repair work, such as
size coarse
portland
Admixture
the replacement of these slabs, is most conve-
aggregate
Sand
cement
W/C
dosage*
3)
(kg/m3)
(kg/m3)
Mix
(kg/m
ratio
(%)
niently done during the winter, after the ship-
ping season, making this test particularly rele-
Control
1047
774
392
0.41
None
vant.
EY11L
1047
774
392
0.41
3.7
EY11H
1047
774
392
0.38
6.3
DP
1047
774
392
0.41
5.2
Site preparation
The site was prepared by jackhammering out
*Weight active ingredient per cement weight.
alternate sections of concrete, replacing 15 cm of
base material with coarse gravel, and setting
Table 2. Concrete placement time.
forms and reinforcing steel. The slabs that re-
mained between the removed sections provided
Mix
Date
Start
work space for finishing operations. A tempo-
Control
15 Mar
11:00 a.m.
rary, propane-heated enclosure (Fig. 2) was erect-
EY11L
16 Mar
9:45 a.m.
ed over one slab as a control section (admixture-
EY11H
16 Mar
11:40 a.m.
DP
17 Mar
1:10 p.m.
free) to provide a comparison between normal
and antifreeze concreting operations. An unheat-
ed enclosure covered one of the admixture sec-
The concrete was transported by rotary-drum
tions as a secondary test. Concrete made with
truck from a ready-mix plant 8 km from the job
admixtures was placed in the two sections ex-
site. The concrete was mixed with unheated ag-
posed to ambient air outside the shelter and in
gregate and heated water. The ingredients, in-
the section in the unheated shelter.
cluding all admixtures, were mixed before being
Figure 2. Temporary heated shelter.
added into the truck (the mix proportions are
Concrete
Two admixtures were tested: the EY11 and DP
given in Table 1). Table 2 gives the concrete place-
prototypes. The EY11 admixture was used in two
ment times. The concrete was delivered 30 to 45
dosages: low and high, designated EY11L and
minutes after water was added to the mix, and it
EY11H. The DP admixture was used in a single
was placed within another 30 minutes. Consoli-
dosage. Both DP and EY11H were capable of pro-
dation and finishing operations took another 45
tecting concrete down to 5C. The EY11L was
to 60 minutes. Table 3 gives the properties of the
expected to work down to around 3C.
fresh concrete.
3
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