ASTM C604-98

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 604 – 98
Standard Test Method for
True Specific Gravity of Refractory Materials by Gas-
Comparison Pycnometer
This standard is issued under the fixed designation C 604; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope assumed to be equal in volume, and there is no sample in either
cylinder. Under these conditions, with the coupling valve
1.1 This test method covers the determination of the true
closed, any change in the position of one piston must be
specific gravity of solid materials, and is particularly useful for
duplicated by an identical stroke in the other in order to
materials that easily hydrate which are not suitable for test with
maintain the same pressure on each side of the differential
Test Method C 135. This test method may be used as an
pressure indicator.
alternate for Test Method C 135, Test Method C 128, and Test
3.3 If a sample, V , is inserted into chamber B, the coupling
x
Method C 188 for determining true specific gravity.
valve closed and both pistons advanced the same amount from
1.2 This standard does not purport to address all of the
position 1 to position 2, the pressures will not remain the same.
safety concerns, if any, associated with its use. It is the
However the pressures can be maintained equal if piston B
responsibility of the user of this standard to establish appro-
instead is moved only to position 3. Then the remaining
priate safety and health practices and determine the applica-
displacement d , from position 3 to position 2, is equal to the
bility of regulatory limitations prior to use. x
volume of the sample, V . If piston A always is advanced
x
2. Referenced Documents exactly the same distance each time a measurement is made,
the distance that piston B differs from position 2, when the
2.1 ASTM Standards:
pressures in both cylinders are equal, will always be propor-
C 128 Test Method for Specific Gravity and Absorption of
tional to the volume, V . The distance (d ) between positions 2
Fine Aggregate x x
and 3 can be calibrated and made to read directly in terms of
C 135 Test Method for True Specific Gravity of Refractory
cubic centimetres, employing a digital counter.
Materials by Water Immersion
C 188 Test Method for Density of Hydraulic Cement
4. Significance and Use
3. Summary of Test Method
4.1 The true specific gravity of a material is the ratio of its
true density, determined at a specific temperature, to the true
3.1 The sample is powdered to ensure permeation of gas
density of water, determined at a specific temperature. Thus,
into all pores. For practical purposes this is assumed to be true
the true specific gravity of a material is a primary property
when the sample passes a No. 325 (45-μm) sieve. The volume
which is related to chemical and mineralogical composition.
of a carefully weighed powdered sample which has first been
4.2 This test method is particularly useful for hydratable
heated to drive off moisture and undesired combined water is
materials which are not suitable for test with Test Method
measured by the gas-comparison pycnometer. Density is cal-
C 135.
culated from the sample weight in grams divided by its volume
4.3 For refractory raw materials and products the true
in cubic centimetres. This is also the specific gravity of the
specific gravity is a useful value for: classification, detecting
sample at room temperature compared to water at 4°C.
differences in chemical composition between supposedly like
3.2 The principle of the gas-comparison pycnometer is as
samples, indicating mineralogical phases or phase changes,
follows: There are two chambers and two pistons as sketched
calculating total porosity when the bulk density is known, and
in Fig. 1. For purposes of illustration, the chambers are
for any other test method that requires this value for the
calculation of results.
This test method is under the jurisdiction of ASTM Committee C-8 on
4.4 This test method is a primary standard method which is
Refractories, and is the direct responsibility of Subcommittee C08.03 on Physical
suitable for use in specifications, quality control, and research
Test and Properties.
and development. It can also serve as a referee test method in
Current edition approved Sept. 10, 1998. Published December 1998. Originally
e1
purchasing contracts or agreements.
published as C 604 – 67. Last previous edition C 604 – 86 (Reapproved 1993) .
Annual Book of ASTM Standards, Vol 04.02.
4.5 Fundamental assumptions inherent in this test method
Annual Book of ASTM Standards, Vol 15.01.
are the following:
Annual Book of ASTM Standards, Vol 04.01.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C 604–98
FIG. 1 Simplified Schematic Diagram
4.5.1 The sample is representative of the material in general, 5.6 Gas-Comparison Pycnometer, equipped with external
purge manifold.
4.5.2 The total sample has been reduced to the particle size
specified,
6. Sample Preparation
4.5.3 No contamination has been introduced during process-
6.1 Grind a sufficient representative sample for three deter-
ing of the sample,
minations to pass a No. 325 (45-μm) sieve. With the Beckman
4.5.4 The ignition of the sample has eliminated all free or
instrument the quantity needed is approximately 150 cm .
combined water without inducing sintering or alteration,
6.2 After grinding, ignite the total sample at a temperature
4.5.5 An inert gas (helium) has been used in the test, and
sufficient to drive off free moisture and any undesired com-
4.5.6 The test method has been conducted in a meticulous
bined water, organic matter, etc., without inducing sintering of
m
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