SHRP-A-379 traducir

2.3 ASTM Standards:
D 4402 Measurement
of Asphalt Viscosity Using a Rotational Viscometer
3. SUMMARY OF TEST METHOD
3.1 The gyratory compactor produces a cylindrical test specimen from a loose
modified or unmodified paving mix through a combination of parallel end pressure and
gyratory kneading.
3.2 A loose paving mix is prepared in the laboratory; short-term oven aged in
accordance with AASHTO M-007; brought to the proper compaction temperature; and placed
into a mold. The mold is placed in the compaction device and an end pressure of 600 kPa is
applied by means of a vertical ram.
3.3 Alternatively, loose plant mix is obtained; immediately brought to the proper
compaction temperature; and placed into a mold. The mold is placed in the compaction
device and an end pressure of 600 kPa is applied by means of a vertical ram.
3.4 The mold is set for a 1.25 ° angle of gyration and the specimen is gyrated at
30 rpm to a predetermined number of gyrations, based on the anticipated traffic for the
roadway.
3.5 The height of the specimen is recorded after each revolution and is used to
calculate the specimen volume. The weight of the mixture and the specimen volume are used
to estimate the specimen density.
3.6 When the compaction is completed, the mold is removed and the test specimen
is extruded for density determination using test method AASHTO T166.
3.6.1 The extruded specimen is not a right angle cylinder. If the specimen is to be
used for accelerated performance-based tests, the ends must be sawed to conform to the
requirements of SHRP P-005.
4. SIGNIFICANCE AND USE
4.1 The specimens are compacted to simulate the density, aggregate orientation,
and structural characteristics obtained in the actual road surface when proper construction
procedure is used in the placement of the paving mix. The specimens may be used to
determine a number of characteristics of bituminous mixtures by specified test methods.
5. APPARATUS
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5.1 Oven--Range at least 40 to 150°C, thermostatically controlled to + 3°C