Table 3. Coarse aggregate gradation. The
13.2- and 9.5-mm headings indicate the
nominal size of the gradation.
Table 4. Fine aggregate.
Percent passing
CRREL
CRREL
Percent passing
Denver Part I & II
Part II
Denver
CRREL
Sieve size
Mix 10 (13.2 mm) (9.5 mm)
Sieve size
Mix 10 Part I & II
9.5 mm
--
--
--
9.5 mm
100
100
38.1 mm
100
100
100
4.75 mm
100
100
26.5 mm
100
100
100
2.36 mm
91
89
19.0 mm
75
100
100
1.18 mm
66
66.3
600 m
13.2 mm
38
69.8
100
38
41.5
300 m
9.5 mm
4
37.3
93.6
16
8.6
150 m
4.75 mm
1
3.2
17
5
6.5
75 m
2.26 mm
0.6
--
--
2.4
3.3
75 m
0.2
--
--
Specific gravity
2.638
2.67
Specific gravity
2.724
2.89
2.89
Absorption
1.1%
1.1%
Absorption
0.76%
0.52%
0.52%
specimens were periodically removed from the
Measurements
oven, sealed in plastic bags until the moisture
The relation between dielectric constant and
evenly distributed itself in the specimens, meas-
water content was developed by taking a TDR
ured with the TDR system, and weighed. (See
reading each time a specimen was dried a small
Results for a description of how drying times
amount. The initial TDR readings were taken
were determined and of how an even moisture
when the specimens were removed from the cur-
ing water and their surfaces were towel-dried to
distribution was determined.) The weights were
saturated surface-dry (ssd) conditions. At that
converted into moisture contents after the speci-
mens reached a constant weight in the 105C
point the specimens were also weighed. The
oven.
specimens, along with the embedded TDR
probes and coaxial cables, were then placed into a
60C drying oven, being careful not to kink the
RESULTS
cables. The specimens were dried at 60C, for all
but the final drying, to prevent any possibility of
Figure 2 presents the drying curves for dum-
melting the coaxial cable. The final drying was
my specimens of concrete and mortar. As previ-
conducted at 105C. During the 60C drying, the
ously mentioned, the specimens instrumented
20
Mortar
Concrete
15
10
5
0
0
100
200
300
400
500
600
700
Drying Time (hr)
Figure 2. Drying curves for 76- 152-mm mortar and concrete cylin-
ders at 60C. The oven-dry condition (final data point) was achieved by
drying the cylinders at 105C.
4
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