ASTM C128-97

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: C 128 – 97
Standard Test Method for
Specific Gravity and Absorption of Fine Aggregate
This standard is issued under the fixed designation C 128; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope D 75 Practice for Sampling Aggregates
E 12 Terminology Relating to Density and Specific Gravity
1.1 This test method covers the determination of bulk and
of Solids, Liquids, and Gases
apparent specific gravity, 23/23°C (73.4/73.4°F), and absorp-
E 380 Practice for Use of the International System of Units
tion of fine aggregate.
(SI) (the Modernized Metric System)
1.2 This test method determines (after 24 h in water) the
2.2 AASHTO Standard:
bulk specific gravity and the apparent specific gravity as
AASHTO No. T 84 Specific Gravity and Absorption of Fine
defined in Terminology E 12, the bulk specific gravity on the
Aggregates
basis of weight of saturated surface-dry aggregate, and the
absorption as defined in Definitions C 125.
3. Significance and Use
NOTE 1—The subcommittee is considering revising Test Methods
3.1 Bulk specific gravity is the characteristic generally used
C 127 and C 128 to use the term “density” instead of “specific gravity” for
for calculation of the volume occupied by the aggregate in
coarse and fine aggregate, respectively.
various mixtures containing aggregate including portland ce-
1.3 The values stated in SI units are to be regarded as the
ment concrete, bituminous concrete, and other mixtures that
standard.
are proportioned or analyzed on an absolute volume basis.
1.4 This standard does not purport to address all of the
Bulk specific gravity is also used in the computation of voids
safety concerns, if any, associated with its use. It is the
in aggregate in Test Method C 29 and the determination of
responsibility of the user of this standard to establish appro-
moisture in aggregate by displacement in water in Test Method
priate safety and health practices and determine the applica-
C 70. Bulk specific gravity determined on the saturated
bility of regulatory limitations prior to use.
surface-dry basis is used if the aggregate is wet, that is, if its
absorption has been satisfied. Conversely, the bulk specific
2. Referenced Documents
gravity determined on the oven-dry basis is used for compu-
2.1 ASTM Standards:
tations when the aggregate is dry or assumed to be dry.
C 29/C 29M Test Method for Unit Weight and Voids in
3.2 Apparent specific gravity pertains to the relative density
Aggregate
of the solid material making up the constituent particles not
C 70 Test Method for Surface Moisture in Fine Aggregate
including the pore space within the particles that is accessible
C 125 Terminology Relating to Concrete and Concrete
to water. This value is not widely used in construction
Aggregates
aggregate technology.
C 127 Test Method for Specific Gravity and Absorption of
3.3 Absorption values are used to calculate the change in the
Coarse Aggregate
weight of an aggregate due to water absorbed in the pore
C 188 Test Method for Density of Hydraulic Cement
spaces within the constituent particles, compared to the dry
C 566 Test Method for Total Moisture Content of Aggregate
condition, when it is deemed that the aggregate has been in
by Drying
contact with water long enough to satisfy most of the absorp-
C 670 Practice for Preparing Precision and Bias Statements
tion potential. The laboratory standard for absorption is that
for Test Methods for Construction Materials
obtained after submerging dry aggregate for approximately 24
C 702 Practice for Reducing Samples of Aggregate to
h in water. Aggregates mined from below the water table may
Testing Size
have a higher absorption when used, if not allowed to dry.
Conversely, some aggregates when used may contain an
amount of absorbed moisture less than the 24 h-soaked
This test method is under the jurisdiction of ASTM Committee C-9 on Concrete
and Concrete Aggregates and is the direct responsibility of Subcommittee C09.20 on
Normal Weight Aggregates. Annual Book of ASTM Standards, Vol 04.03.
Current edition approved Nov. 10, 1997. Published October 1998. Originally Annual Book of ASTM Standards, Vol 15.05.
published as C 128 – 36. Last previous edition C 128 – 93. Annual Book of ASTM Standards, Vol 14.02. Excerpts in all volumes.
2 7
Annual Book of ASTM Standards, Vol 04.02. Available from American Association of State Highway and Transportation
Annual Book of ASTM Standards, Vol 04.01. Officials, 444 North Capitol St. N.W., Suite 225, Washington, DC 20001.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
C 128
condition. For an aggregate that has been in contact with water saturated surface-dry condition. Continue this operation until
and that has free moisture on the particle surfaces, the the test specimen approaches a free-flowing condition. Follow
percentage of free moisture can be determined by deducting the
the procedure in 6.2.1 to determine whether or not surface
absorption from the total moisture content determined by Test moisture is present on the constituent fine aggregate particles.
Method C 566 by drying.
It is intended that the first trial of the cone test will be made
with some surface water in the specimen. Continue drying with
4. Apparatus
constant stirring and test at frequent intervals until the test
4.1 Balance—A balance or scale having a capacity of 1 kg
indicates that the specimen has reached a surface-dry condi-
or more, sensitive to 0.1 g or less, and accurate within 0.1 % of
tion. If the first trial of the surface moisture test indicates that
the test load at any point within the range of use for this test.
moisture is not present on the surface, it has been dried past the
Within any 100-g range of test load, a difference between
saturated surface-dry condition. In this case thoroughly mix a
readings shall be accurate within 0.1 g.
few millilitres of water with the fine aggregate and permit the
4.2 Pycnometer—A flask or other suitable container into
specimen to stand in a covered container for 30 min. Then
which the fine aggregate test sample can be readily introduced
resume the process of drying and testing at frequent intervals
and in which the volume content can be reproduced within
for the onset of the surface-dry condition.
60.1 cm . The volume of the container filled to mark shall be
6.2.1 Cone Test for Surface Moisture—Hold the mold firmly
at least 50 % greater than the space required to accommodate
on a smooth nonabsorbent surface with the large diameter
the test sample. A volumetric flask of 500 cm capacity or a
down. Place a portion of the partially dried fine aggregate
fruit jar fitted with a pycnometer top is satisfactory for a 500-g
loosely in the mold by filling it to overflowing and heaping
test sample of most fine aggregates. A Le Chatelier flask as
additional material above the top of the mold by holding it with
described in Test Method C 188 is satisfactory for an approxi-
the cupped fingers of the hand holding the mold. Lightly tamp
mately 55-g test sample.
the fine aggregate into the mold with 25 light drops of the
4.3 Mold—A metal mold in the form of a frustum of a cone
tamper. Each drop should start about 5 mm (0.2 in.) above the
with dimensions as follows: 40 6 3 mm inside diameter at the
top surface of the fine aggregate. Permit the tamper to fall
top, 90 6 3 mm inside diameter at the bottom, and 75 6 3mm
freely under gravitational attraction on each drop. Adjust the
in height, with the metal having a minimum thickness of 0.8
starting height to the new surface elevation after each drop and
mm.
distribute the drops over the surface. Remove loose sand from
4.4 Tamper—A metal tamper weighing 3406 15 g and
the base and lift the mold vertically. If surface moisture is still
having a flat circular tamping face 25 6 3 mm in diameter.
present, the fine aggregate will retain the molded shape. When
the fine aggregate slumps slightly it indicates that it has
5. Sampling
reached a surface-dry condition. Some angular fine aggregate
5.1 Sampling shall be accomplished in general accordance
or material with a high proportion of fines may not slump in the
with Practice D 75.
cone test upon reaching a surface-dry condition. This may be
6. Preparation of Test Specimen the case if fines become airborne upon dropping a handful of
the sand from the cone test 100 to 150 mm onto a surface. For
6.1 Obtain approximately 1 kg of the fine aggregate from
these materials the saturated surface-dry condition should be
the sample using the applicable procedures described in
considered as the point that one side of the fine aggregate
Practice C 702.
slumps slightly upon removing the mold.
6.1.1 Dry the test specimen in a suitable pan or vessel to
constant weight at a temperature of 110 6 5°C (230 6 9°F).
NOTE 3—The following criteria have also been used on materials that
Allow it to cool to comfortable handling temperature, cover
do not readily slump:
with water, either by immersion or by the addition of at least
(1) Provisional Cone Test—Fill the cone mold as described in 6.2.1
6 % moisture to the fine aggregate, and permit to stand for 24
except only use 10 drops of the tamper. Add more fine aggregate and use
6 4h.
10 drops of the tamper again. Then add material two more times using 3
and 2 drops of the tamper, respectively. Level off the material even with
6.1.2 As an alternative to 6.1.1, where the absorption and
the top of the mold, remove loose material from the base; and lift the mold
specific gravity values are to be used in proportioning concrete
vertically.
mixtures with aggregates used in their naturally moist condi-
(2) Provisional Surface Test—If airborne fines are noted when the fine
tion, the requirement for initial drying to constant weight may
aggregate is such that it will not slump when it is at a moisture condition,
be eliminated and, if the surfaces of the particles have been
add more moisture to the sand, and at the onset of the surface-dry
kept wet, the 24-h soaking may also be eliminated.
condition, with the hand lightly pat approximately 100 g of the material on
a flat, dry, clean, dark or dull nonabsorbent surface such as a sheet of
NOTE 2—Values for absorption and for specific gravity in the saturated
rubber, a worn oxidized, galvanized, or steel surface, or a black-painted
surface-dry condition may be significantly higher for aggregate not oven
metal surface. After 1 to 3 s remove the fine aggregate. If noticeable
dried before soaking than for the same aggregate treated in accordance
moisture shows on the test
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