The Clarksburg telegram. [volume] (Clarksburg, W. Va.) 1874-1926, 1912-08-22
Tests
With High Pressure Steam
Are Being Made on
Portland Cement.

1 Va tAaAIA N@EllAOllt.
WASHINGTON, D. c.. Aug. 2O.-
The Bureau of Standards, OF the DE.
partment OF Commerce and Labor. IL
connection with the Investigation o.
structural materials is conducting q
series OF tests to determine the action
Of high pressure steam on Portland
cement. II has been found that high
pressure steam win greatly accelerate
the hardening OF certain cemehts. In
creasins their strength several hun
dred per cent. but Will cause the COM
plete dlslntegration OF other cements
which under normal conditions APP
pear to have the usual physical quail
tiles. The present Investigation is IN
part an extension OF the work report
ed In Technologic Paper No. 5, THE
Eject Of High Pressure Steam on the
Crushing Strength OF Portland ce-
tnent Mortar and and concrete.p The
equipment for this purpose consists
Of small steam pressure tank, or so.
called "autoclave." suitable for pres
sures up to so atmospheres (5l5
pounds per square inch) and large
cylindrical steel tank ~ inches by .
feet inside dimensions suitable for
working pressures up to 20 atmos-
pheres u,oSO pounds per square
lnch).
1t has been proposed that apecjfl-
cations for the purchase of Portland
cement be amended to include test
Of exposing cement to steam pres
sure of 90 atmospheres C2s4 pounds
per square inch) for period OF two
hours. 1t Is required that the cement,
remain sound and that the tension
briauettes show given Increase In.
strength. Il
It has been found that certain ce-
ments which meet the steam test of
212 degrees F. for 5 hours, as required
by present specifications fall under the
proposed high-pressure steam test.
In investigating the cause and inter-
probation of this failure, practically
all brands of cement purchased by
the government are being subjected to
the iiigh-pressure steam test in con-
nection with the regular routine spec
ification test, and much valuable In
formation is being accumulated.
Tests are also being made on spec
tally prepared cements Of various de-
grees OF Oneness and after seasoning
for different periods. Other series Of
tests are being made In exposing ce.
ments neat. and in mortars and con-
'cretes TO series Of pressures ranging
up TO 1000 pounds per square inch
for various duratlons. Tensile and
compressiye strength, linear expan-
sion and contraction, water absorp-
ton and other physical properties are
being determined. The effect of tenn
perature, pressure, and moisture con-
tent of the atmosphere, or degree Of
water saturation, are being studied in
dependentiy.
Some interesting results are also
being obtained by subjecting to high
pressure steam pieces OF mortar and
concrete from sound and dtsintegrated
structures, which has been in place
for several years.
To determine the. value OF the
high-pressure steam test as deter
mination OF the soundness and struc-
turai quality OF Portland cements, al
large number OF concrete cylinders,
inches in diameter by l6 inches in
length. are being made of cement
which fails to meet the normal 212
degrees F. steam test, as well as OF
cement which passes this test but
fails to meet the proposed 20 atmos-
phere pressure test. and of CO.
ment which meets both of the above
requirements. The cements are being
tested in normal 1924 proportion
concrete mixture and will be exposed
in various localities over period Of
years and tested for elastic proper
ties and compdessive strength.