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Standard Test Method for
Surface Moisture in Fine Aggregate1
This standard is issued under the fixed designation C 70; 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 thelast revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method covers field determination of the
amount of surface moisture in fine aggregate by displacement
in water.
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user ofthis standard to establish appropriate
safety and health practices and determine the applicability
of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
C 128 Test Method for Specific Gravity and Absorption of
Fine Aggregate2
C 566 Test Method for Total Moisture Content of Aggregate
by Drying2
C 670 Practice for Preparing Precision and Bias Statements
forTest Methods for Construction Materials2
3. Significance and Use
3.1 This test method is not widely used. However, it is a
convenient procedure for field or plant determination of
moisture content of fine aggregate if specific gravity values are
known and if drying facilities are not available. It can be used
to adjust aggregate weights for moisture content and to
determine surface moisturecontribution to mixing water in
portland cement concrete.
3.2 The accuracy of the test method depends upon accurate
information on the bulk specific gravity of the material in a
saturated surface-dry condition.
4. Apparatus
4.1 Balance, having a capacity of 2 kg or more and sensitive
to 0.5 g or less.
4.2 Flask—Asuitable container or flask, preferably of glass
or noncorrosive metal. Thecontainer may be a pycnometer, a
volumetric flask, a graduated volumetric flask, or other suitable
measuring device. The volume of the container shall be from
two to three times the loose volume of the sample. The
container shall be so designed that it can be filled to the mark,
or the volume of its contents read, within 0.5 mL or less.
5. Sample
5.1 Select a representative sample of the fineaggregate to be
tested for surface moisture content. It shall weigh not less than
200 g. Larger samples will yield more accurate results.
6. Procedure
6.1 The surface water content may be determined either by
weight or volume. In each case the test shall be made at a
temperature range of 65 to 85°F (18 to 29°C).
6.2 Determination by Weight—Determine the weight of the
container, in grams,filled to the mark with only water. Before
placing the sample into the container, adjust the level of the
water so that it will be sufficient to cover the sample without
going over the original mark. Introduce the weighed sample of
fine aggregate into the container and remove the entrained air.
Fill the container to the original mark, and determine the
weight in grams. Calculate the amount ofwater displaced by
the sample, as follows:
Wd 5 Wc 1 Ws 2 W (1)
where:
Wd = weight of water displaced by the sample, g,
Wc = weight of container filled to the mark with water, g,
Ws = weight of sample, g, and
W = weight of container and sample, filled to the mark
with water, g.
6.3 Determination by Volume—Measure a volume of water,
in millilitres, sufficient to cover the sample andplace in the
container. Introduce the weighed sample of fine aggregate into
the container and remove the entrained air. Determine the
combined volume of the sample and the water by direct reading
when a graduated flask is used. When a pycnometer or
volumetric flask of known volume is used, fill the container to
the known volume mark with an additional measured volume
of water. The flask or...
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