ASTM D7172-06
(Test Method)Standard Test Method for Determining The Relative Density (Specific Gravity) And Absorption Of Fine Aggregates Using Infrared
Standard Test Method for Determining The Relative Density (Specific Gravity) And Absorption Of Fine Aggregates Using Infrared
SIGNIFICANCE AND USE
Bulk relative density (specific gravity) is the characteristic generally used for calculation of the volume occupied by the aggregate in various mixtures containing aggregate including Portland cement concrete, bituminous concrete, and other mixtures that are proportioned or analyzed on an absolute volume basis. Bulk relative density (specific gravity) is used in the computation of voids in aggregate in C 1252 and C 29/ C 29M. Bulk relative density (specific gravity) determined on the saturated surface dry (SSD) basis is used if the aggregate is wet, that is, if its absorption has been satisfied. Conversely, the bulk relative density (specific gravity) determined on the oven-dry basis is used for computations when the aggregate is dry or assumed to be dry.
Apparent relative density (specific gravity) pertains to the relative density of the solid material making up the constituent particles not including the pore space within the particles that is accessible to water. This value is not widely used in construction aggregate technology.
Water absorption values are used to calculate the change in the mass of an aggregate due to water absorbed in the pore spaces within the constituent particles, compared to the dry condition, when it is deemed that the aggregate has been in contact with water long enough to satisfy most of the absorption potential. The laboratory standard for absorption is that obtained after submerging dry aggregate for approximately 24 hours in water. Aggregates mined from below the water table may 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 hours soaked condition: For an aggregate that has been in contact with water and that had free moisture on the particle surface, the percentage of free moisture can be determined by deducting the absorption from the total moisture content determined according to C 566 by drying.
SCOPE
1.1 This test method covers the determination of the relative density (specific gravity) and absorption of fine aggregates.
1.2 The values stated in SI units are to be regarded as the standard.
1.3 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 of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 7172 – 06
Standard Test Method for
Determining The Relative Density (Specific Gravity) And
Absorption Of Fine Aggregates Using Infrared
This standard is issued under the fixed designation D 7172; 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 2.2 AASHTO Standards:
T-84 Test Method for Specific Gravity and Absorption of
1.1 Thistestmethodcoversthedeterminationoftherelative
Fine Aggregate
density (specific gravity) and absorption of fine aggregates.
2.3 Other Documents:
1.2 The values stated in SI units are to be regarded as the
Operational Instructions
standard.
1.3 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions—As defined in C 125 andD8
responsibility of the user of this standard to establish appro-
3.1.1 Automatic Volumetric Mixer (AVM), n—an automated
priate safety and health practices and determine the applica-
unit to hold and agitate a volumetric flask while applying a
bility of regulatory limitations prior to use.
vacuum to the flask.
2. Referenced Documents
4. Significance and Use
2.1 ASTM Standards:
4.1 Bulk relative density (specific gravity) is the character-
C 29/C 29M Test Method for Bulk Density (“Unit Weight”)
istic generally used for calculation of the volume occupied by
and Voids in Aggregate
the aggregate in various mixtures containing aggregate includ-
C 125 Terminology Relating to Concrete and Concrete
ing Portland cement concrete, bituminous concrete, and other
Aggregates
mixtures that are proportioned or analyzed on an absolute
C 128 Test Method for Density, Relative Density (Specific
volume basis. Bulk relative density (specific gravity) is used in
Gravity), and Absorption of Fine Aggregate
the computation of voids in aggregate in C 1252 and C 29/
C 566 Test Method for Total Evaporable Moisture Content
C 29M. Bulk relative density (specific gravity) determined on
of Aggregate by Drying
the saturated surface dry (SSD) basis is used if the aggregate is
C 670 Practice for Preparing Precision and Bias Statements
wet, that is, if its absorption has been satisfied. Conversely, the
for Test Methods for Construction Materials
bulk relative density (specific gravity) determined on the oven-
C 702 Practice for Reducing Samples of Aggregate to
dry basis is used for computations when the aggregate is dry or
Testing Size
assumed to be dry.
C 1252 Test Methods for Uncompacted Void Content of
4.2 Apparent relative density (specific gravity) pertains to
Fine Aggregate (as Influenced by Particle Shape, Surface
the relative density of the solid material making up the
Texture, and Grading)
constituent particles not including the pore space within the
D8 Terminology Relating to Materials for Roads and Pave-
particles that is accessible to water. This value is not widely
ments
used in construction aggregate technology.
D75 Practice for Sampling Aggregates
4.3 Water absorption values are used to calculate the change
D 4753 Guide for Evaluating, Selecting, and Specifying
in the mass of an aggregate due to water absorbed in the pore
Balances and Standard Masses for Use in Soil, Rock, and
spaces within the constituent particles, compared to the dry
Construction Materials Testing
condition, when it is deemed that the aggregate has been in
contact with water long enough to satisfy most of the absorp-
This test method is under the jurisdiction of ASTM Committee D04 on Road
tion potential. The laboratory standard for absorption is that
and Paving Materials and is the direct responsibility of Subcommittee D04.51 on
Aggregate Tests.
Current edition approved Feb. 15, 2006. Published March 2006.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from American Association of State Highway and Transportation
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001.
Standards volume information, refer to the standard’s Document Summary page on Available from Barnstead International, 2555 Kerper Boulevard, P.O. Box 797,
the ASTM website. Dubuque, Iowa 52004-0797, U.S.A.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7172–06
obtained after submerging dry aggregate for approximately 24 7.3 Split the test sample according to Practice C 702 into
hours in water. Aggregates mined from below the water table two 500 6 5g samples. Discard excess.
may have a higher absorption when used, if not allowed to dry.
Conversely, some aggregates when used may contain an 8. Calibration
amount of absorbed moisture less than the 24 hours soaked
8.1 Calibration of the water pump and the infrared unit shall
condition: For an aggregate that has been in contact with water
be performed once a month.
and that had free moisture on the particle surface, the percent-
8.2 Calibration of Water Pump:
age of free moisture can be determined by deducting the
8.2.1 Fill the infrared device with distilled water per manu-
absorption from the total moisture content determined accord-
facturers’ instructions.
ing to C 566 by drying.
8.2.2 Weigh a clean container. Place the container under the
nozzle in the lid to collect the water. Position the container so
5. Apparatus
as to minimize splashing. (Note 2).
5.1 Balance—Abalanceorscale,conformingtotherequire-
NOTE 2—A 125 mL Erlenmeyer flask or similar container is recom-
ments of D 4753, accurate and readable to within 0.1 % of the
mended.
test sample mass at any point within the range of use.
8.2.3 Follow manufacturers’ instructions regarding initia-
5.2 Thermometer—Shall be capable of accurately measur-
tion of an automatic preset number of injections from the
ing the temperature throughout a range of 0° to 50° C, and be
nozzle into the test flask. (Note 3)
readable to 0.5° C (1° F).
5.3 Large Neck Volumetric Flask—with a capacity of 500
NOTE 3—A total of 3000 injections is recommended.
mL.
8.2.4 At the end of the collection cycle, remove the con-
5.4 Timer—capable of at least 5 minutes.
tainer and place it on a scale to obtain the total mass. Subtract
5.5 AVM Unit (Automatic Volumetric Mixer)—The unit
theemptycontainermassobtainedinstep8.2.2fromthisvalue
shallperformanautomatedprocessforremovingentrappedair.
and enter the resulting amount into the Infrared device, per
It shall consist of the following devices: an orbiting mixer that
manufacturers’ instructions.
can securely hold a 500 mL large neck volumetric flask, a
8.3 Calibration of Infrared Unit:
clamp and clamping rod capable of securely holding the neck
8.3.1 Check and ensure that the water reservoir on the
of the volumetric flask, a vacuum pump, hose, and a stopper
infrared unit is full. Turn on the power to the unit and allow it
capable of fitting the mouth of the volumetric flask. (See Note
to warm-up per manufacturers’ instructions.
1)
8.3.2 Initiate infrared unit calibration routine per manufac-
5.6 Infrared Unit—The device shall be automatically ca-
turers’ instructions.
pable of detecting SSD using an infrared source and detector.
8.3.3 Insert exactly 500.0 g of Ottawa Silica sand into the
Itshallconsistofanorbitalmixer,waterpump,infraredsource,
mixing bowl and initiate the calibration process.After the unit
infrared detector, and a mixing bowl with a lid. The lid of the
completes the calibration procedure, the unit will indicate the
mixingbowlshallconsistoftwosapphirelensesandcontainan
calibration result. (Note 4)
injection nozzle for water injection. (See Note 1)
8.3.4 Return to the normal operation mode of the unit per
NOTE 1—Units similar to the SSDetect manufactured by Barnstead the manufacturers’ instructions.
International meet criteria described in Sections 5.3, 5.5 and 5.6
8.3.5 Dry the Ottawa silica sand back to a constant mass at
a temperature of 110 6 5°C (230 6 9°F), so it can be used for
5.7 Distilled Water
future calibrations.
6. Sampling
NOTE 4—A calibration material can be obtained from the unit manu-
facturer. When the calibration result is shown, it indicates that the
6.1 Sampling shall be accomplished in accordance with
calibration process is complete.
PracticeD75.
9. Procedure
7. Preparation of Test Specimen
9.1 Make and record all mass determinations to 0.1 g.
7.1 Obtain 1.5 kg 6 10 g of the fine aggregate from the
9.2 Determine the mass of a 500 ml, large neck volumetric
sample using the applicable procedures described in Practice
flask filled to its calibration capacity with water at 23 6 2.0°C
C 702.
(73 6 3°F). Record the mass and discard the water.
7.2 Dry it in a suitable pan or vessel to constant mass at a
9.3 Film Coeffıcient andApparent Relative Density (Specific
temperature of 110 6 5°C (230 6 9°F).Allow it to cool to 23
Gravity) Determination:
6 2.0°C (73 6 3°F).
9.3.1 Place approximately 250 mL of 23 6 2.0°C (73 6
3°F) water in the flask measured in 9.2.
9.3.2 Place the flask and water from 9.3.1 on a balance and
zero the balance.
The sole source of supply of the apparatus known to the committee at this
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.