EXPANSION AND CONTRACTION OF CONCRETE. 
00015 
0-0014. 
I^^^lL 
I nl 
bring it to constant temperature as determined by a thermometer 
likewise hung beside the specimen. A thermometer was inserted 
also in- a horizontal orifice in the middle of 
the concrete specimen, and the tempera- 
ture was noted at each reading. Finally, 
all readings were corrected to eliminate 
the effect of differences in temperature, 
whether due to chemical activity of the 
cement in hardening or to external 
changes. In figure 2 is shown a specimen 
with measuring instrument attached. 
RESULTS OF EXPANSION AND CONTRAC- 
TION MEASUREMENTS. 
The results of these laboratory measure- 
ments are best seen by reference to the 
following curves : 
AGE. VIM OAYS ' 
0O000 
00001 
00002 
QOO03 
00004 
00005 
0.000b 
O 0-0007 
P 
q 
<o-oooa 
tc 
y- 
Z 00009 
o 
V 
. 0.0010 
h 
30-0011 
00012 
00013 
O-00V4- 
Fig. 2. — Specimen and appa-- 
ratus for measuring the ex- 
pansion and contraction of 
concrete. 
NEAT CEMENT, STORED IN AIR. 
On figure 3 is shown a typi- 
cal shrinkage curve of neat 
cement stored in the w r arm, 
dry air of the laboratory. It 
will be seen that shrinkage 
takes place immediately, and at the age of 6 months a total shrinkage of 0.155 
per cent, or If inches, in 100 feet took place. This is much less than the results 
of White, who observed a shrinkage of 0.236 per cent, or 2£ inches, in 100 feet. 
Fig. 3. — Neat cement, stored in air. 
