ASTM D3387-83(1996)
(Test Method)Standard Test Method for Compaction and Shear Properties of Bituminous Mixtures by Means of the U.S. Corps of Engineers Gyratory Testing Machine (GTM)
Standard Test Method for Compaction and Shear Properties of Bituminous Mixtures by Means of the U.S. Corps of Engineers Gyratory Testing Machine (GTM)
SCOPE
1.1 This test method employs two separate modes of operation of the Gyratory Testing Machine (GTM), namely: (a) GTM fixed roller mode; and (b) GTM oil-filled roller mode. The fixed roller mode of operation is employed in testing for compaction and strain indices only, while the oil-filled roller mode of operation is employed in testing for strength properties as well as compaction and strain indices. This test method is for use with mixtures containing asphalt cement, asphalt cut-back, asphalt emulsion, or tar and aggregate up to 1 in. (25.4 mm) maximum size in the 4-in. (101.6-mm) diameter specimen and 1.5 in. (38.1 mm) maximum size in the 6-in. (152.4-mm) diameter specimen.
1.2 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation: D 3387 – 83 (Reapproved 1996)
Standard Test Method for
Compaction and Shear Properties of Bituminous Mixtures
by Means of the U.S. Corps of Engineers Gyratory Testing
Machine (GTM)
This standard is issued under the fixed designation D 3387; 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 3.1.2.2 Minimum gyratory angle or shear strain (minimum
gyrograph band width) u (see Fig. 1), and
i
1.1 This test method employs two separate modes of opera-
3.1.2.3 Maximum gyratory angle or shear strain (maximum
tion of the Gyratory Testing Machine (GTM), namely: (a)
gyrograph band width) u (see Fig. 1).
GTM fixed roller mode; and (b) GTM oil-filled roller mode. max
3.1.3 gyratory stability index (GSI)—the ratio of the maxi-
The fixed roller mode of operation is employed in testing for
mum gyratory angle to the minimum gyratory angle (see Fig.
compaction and strain indices only, while the oil-filled roller
1).
mode of operation is employed in testing for strength proper-
3.1.4 gyratory compactibility index (GCI)—the ratio of the
ties as well as compaction and strain indices. This test method
unit mass (total mix) at 30 revolutions of the GTM to the unit
is for use with mixtures containing asphalt cement, asphalt
mass (total mix) at 60 revolutions of the GTM.
cut-back, asphalt emulsion, or tar and aggregate up to 1 in.
3.1.5 gyratory shear strength (S )—the shear resistance of
G
(25.4 mm) maximum size in the 4-in. (101.6-mm) diameter
the specimen which is, among other things, a function of the
specimen and 1.5 in. (38.1 mm) maximum size in the 6-in.
imposed vertical pressure and degree of strain (see Annex A1).
(152.4-mm) diameter specimen.
3.1.6 gyratory shear factor (GSF)—the ratio of the mea-
1.2 This standard does not purport to address all of the
sured gyratory shear strength to the approximate theoretical
safety concerns, if any, associated with its use. It is the
maximum induced shear stress, that is, a factor of safety type
responsibility of the user of this standard to establish appro-
index with regard to failure in simple shear for the defined
priate safety and health practices and determine the applica-
loading conditions.
bility of regulatory limitations prior to use.
4. Significance and Use
2. Referenced Documents
4.1 Either mode of operation (fixed roller or oil-filled roller)
2.1 ASTM Standards:
is intended to be used for guidance in selection of the optimum
C 136 Test Method for Sieve Analysis of Fine and Coarse
bitumen content and establishing unit mass requirements;
Aggregates
additionally the oil-filled roller mode of operation is intended
C 670 Practice for Preparing Precision and Bias Statements
for use in arriving at a shear strength factor (referred to as
for Test Methods for Construction Materials
gyratory strength factor, GSF) with regard to shear under the
3. Terminology
load and strain conditions selected for the test. The procedure
described here is for one selected degree of shear strain (in this
3.1 Definitions:
case an initial gyratory angle of 1°) and some selected vertical
3.1.1 gyrograph—a recording of shear strain experienced
pressure (in this case the anticipated tire contact pressure).
by the bituminous mixture during the compaction test (see Fig.
Attention is called to the fact that the gyratory angle selected
1).
should relate to the anticipated pavement deflection. The 1°
3.1.2 gyratory angle—a measure of the magnitude of the
angle selected here should have wide application but should the
gyratory strain. Three pertinent angles are defined as follows:
pavement engineer select a different shear angle (such as a
3.1.2.1 Initial gyratory angle or shear strain (machine set-
degree of shear strain), it should be so indicated in the report.
ting) u (see Fig. 1),
o
It is essential that the vertical pressure correspond to the
maximum anticipated tire contact pressure, since the theoreti-
This test method is under the jurisdiction of ASTM Committee D-4 on Road
cal stress for compaction and maximum induced shear used in
and Paving Materials and is the direct responsibility of Subcommittee D04.26 on
determining the compaction requirements and the gyratory
Fundamental/Mechanistic Tests.
strength factor (GSF) is based on the concept of employing
Current edition approved Sept. 30, 1983. Published November 1983. Originally
published as D 3387 – 74 T. Last previous edition D 3387– 78. realistic loads for the test.
Annual Book of ASTM Standards, Vol 04.02.
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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.
D 3387 – 83 (1996)
FIG. 1 GTM Compaction and Shear Test
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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D 3387 – 83 (1996)
FIG. 2 Gyratory Testing Machine
4.2 The gyratory strength factor (GSF) must be interpreted 5. Apparatus
with due recognition of the use of the somewhat arbitrarily
5.1 Gyratory Testing Machine (GTM) and Appurtenances—
selected degree of strain and the assumption of plane maximum
The primary equipment for this test is the Gyratory Testing
shear (the unit contact pressure divided by p) for a strip load
Machine (GTM) and appurtenances. Fig. 2 is an assembly
on a homogeneous elastically isotropic mass.
drawing of the machine (and appurtenant equipment) indicat-
4.3 The use of this method for guidance in the selection of
ing essential features, including the wall friction apparatus and
the optimum bitumen content is limited to mixtures that are
a schematic of the gyrating mechanism. The fixed upper roller
susceptible to the development of excess pore pressure when
and the oil-filled upper roller are interchangeable; the roller
the voids become overfilled with bitumen. (This restriction
being selected to fit the mode of operation of the GTM.
does not apply to the gyratory strength factor, GSF.) A gyratory
5.2 Ovens—Ventilated ovens shall be provided for heating
stability index (GSI), in excess of unity, indicates a progressive
aggregates, bituminous material, and specimen molds and for
increase in plasticity during densification. An increase in this
curing cut-back mixes and emulsion mixes. It is recommended
index indicates an excessive bitumen content for the compac-
that the heating units be thermostatically controlled so as to
tion pressure employed and foretells instability of the bitumi-
maintain the required temperature within 5°F (2.8°C).
nous mixture for the loading employed. A reduction in oil-filled
5.3 Balances, one having a capacity of 5 kg or more,
roller pressure during the compaction process likewise indi-
sensitive to 1.0 g; and one having a capacity of 2 kg, sensitive
cates loss of stability because of overfilled voids; this phenom-
to 0.1 g.
enon also serves as an indicator of maximum allowable
bitumen content as does the widening of the gyrograph which
gives a stability index in excess of unity.
4.4 The gyratory compactibility index (GCI) is an indicator
A novel mechanization of the original Texas gyratory principle. This machine
of the compactibility of the mix. The closer this index
is manufactured by Engineering Developments Co., Inc. of Vicksburg, MI 39180,
approaches unity, the easier the mix is to compact. under letters Patent Nos. 2972249 and 3478572.
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.
D 3387 – 83 (1996)
5.4 Thermometers—Armored glass or dial-type thermom- aggregate (aggregate shall be separated by means of a No. 4
eters with metal stems are recommended. A range from 50 to (4.75-mm) sieve). Separate the aggregate into the various size
400°F (9.9 to 20.4°C) with sensitivity of 5°F (2.8°C) is fractions necessary for accurately recombining into test mix-
required. tures conforming to specified grading requirements.
5.5 Spacer Blocks, two metal spacer blocks for use in 6.3 Preparation of Mixtures—Combine the moisture-free
zeroing the specimen height measuring equipment. These shall aggregates into batches sufficiently large to make specimens
all be of 2-in. (50.8-mm) diameter with one each of the approximately 2.50 in. (63.5 mm) long in the 4-in. (101.6-mm)
following lengths: 2.506 0.005 in. (63.50 6 0.013 mm) and diameter mold and 3.75 in. (95.3 mm) long in the 6-in.
3.75 6 0.005 in. (95.25 6 0.013 mm). (152.4-mm) diameter mold. For normal aggregates, this will
5.6 Miscellaneous Apparatus—Trowels, spatulas, scoops, require approximately 1200 g for the 4-in. (101.6-mm) diam-
gloves, rubber gloves, metal pans, 4-in. (101.6-mm) diameter eter specimens and approximately 4050 g for the 6-in. (152.4-
paper disks, and 6-in. (152.4-mm) diameter paper disks. mm) diameter specimens. Heat the aggregate to the proper
mixing temperature; then weigh the required amount of bitu-
6. Test Specimens
men at the proper temperature into the aggregate mixture.
6.1 Selection of Bitumen Content for Specimens—Conduct Mixing of the aggregate and bitumen shall be as thorough and
laboratory tests for one specimen each at a minimum of three
rapid as possible; mechanical mixing is recommended.
bitumen contents, one above, one below, and one at the
NOTE 1—A first approximation of the optimum amount of bitumen for
estimated optimum content (see Note 1). The incremental
the aggregate may be determined by any method commonly employed by
change of bitumen content should generally be 0.5 %. For
the laboratory. A method that has been found suitable in some laboratories
extremely critical mixes, lower the incremental change of
is the centerfuge kerosene equivalent method.
bitumen content to 0.3 % and for highly absorptive aggregates,
6.3.1 For mixes employing penetration/viscosity grades of
increase the incremental change of bitumen content to 1.0 %.
asphalt, the temperature of the aggregate and asphalt at the
Tests on additional bitumen contents should be conducted as
necessary when check tests are needed.
6.2 Preparation of Aggregates—In accordance with Test
Method C 136, obtain a sieve analysis on the fine and coarse California Highways and Public Works, Vol 20, No. 7, July 1942, pp. 14-17.
FIG. 3 GTM Shear Test
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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D 3387 – 83 (1996)
time of mixing should correspond to the temperatures antici- 6-in. (152.4-mm) diameter specimens shall be approximately
pated to be used at the plant during manufacture of the paving 3.75 in. (95.3 mm) long.
mix. These temperatures will generally be somewhere in the
7. Calibration
range of 250 to 325°F (121 to 149°C). Once the mixing
temperature is selected, it should be so controlled that the 7.1 See Annex A2.
viscosity of the bitumen will not vary more than 650 cSt
8. Procedure
during the mixing process.
6.3.2 For tar mixtures, the temperature of the aggregate and 8.1 General—The GTM-fixed roller is employed when the
tar at the time of mixing should correspond to the temperatures compaction test only is required. The GTM oil-filled roller is
to be used at the plant during manufacture of the paving mix. employed when both the compaction test and the shear test are
This temperature will generally not exceed 225°F (107°C). required. The oil-filled roller procedure is accomplished in
Once the mixing temperature is specified, it should be so sequential steps including the compaction test, shear test, and
controlled that the viscosity of the tar will not vary more than wall friction test as outlined in this section. (The procedure for
65 Engler specific viscosity during the mixing process. determining the machine correction for S is presented in
G
6.3.3 For mixtures employing liquid asphalts (cut backs or Annex A2.) When using the fixed roller, inapplicable portions
of the following instructions are ignored.
emulsions), the asphalt need not be heated but the aggregate
should be dried to constant weight at 221 to 230°F (105 to 8.2 Compaction or Compaction and Shear Test—Fig. 1 and
Fig. 3 illustrate data sheets which are suitable for recording and
110°C). The liquid asphalt should be combined with the
aggregate at room temperature. Following mixing, cure the calculating compaction or compaction and shear test results
loose mixture in a ventilated oven maintained at 221 to 230°F and for displaying the gyrograph (shear strain) recording. The
(105 to 110°C) for at least 12 h prior to compaction at this gyratory strain angles u , u , and u are indicated on the
o i max
temperature. The mix may be stirred occasionally during gyrograph displayed in Fig. 1. For this test, set the initial
curing to accelerate loss of volatiles. gyratory angle, u , at 1°. Roller positions 2 and 4 (Fig. 1) are
o
6.4 Size of Specimens—The 4-in. (101.6-mm) diameter used in setting the initial gyratory angle, u . A trial batch of mix
o
specimens shall be approximately 2.50 in. (63.5 mm) long. The is used in making the initial gyratory angle adjustment. Make
FIG. 4 Compaction and Shear Properties vs. Bitumen Content
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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D 3387 – 83 (1996)
certain that the specimen molds are thoroughly clean and free gage shall be recorded in the space provided as illustrated in
of defects. Excessive wear or grooving in the molds in the area Fig. 3. Immediately after completion of the wall friction test,
the test specimen should be removed from the GTM and the
of contact with the upper and lower plates will have an adverse
effect upon the compaction as well as the gyrograph (shear lower roller brought back to the 1° setting so that the machine
is ready for the next test specimen.
strain) recording. Instructions for the compaction temperatures
for the laboratory specimens are presented in 6.3.1 through
9. Calculations
6.3.3. Set the GTM heater at 140°F (60°C) at least 15 min
before starting the compactio
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