SHRP-A-379 traducir

9.1.1.2.3 A thermocouple probe shall be used to measure the sample temperature by
inserting the probe into a sample that has been mounted in the rheometer (this procedure is
described in section 10). The thermocouple must be calibrated at 3 month intervals using the
procedure described in note 5 to the nearest 0.1 °C. When obtaining the sample temperature
the cabling and instrumentation must remain unchanged from that used during the calibration.
To make a sample temperature reading insert the thermocouple in the asphalt binder between
the plates and proceed as described in section 6.1.2.3. A suitable thermocouple probe is
available from Omega as part number HYP1-30-1/2-T-G-60-SMP-M.
9.1.2 Calibrate the load transducer in accordance with the directions and f'Lxtures
supplied with the apparatus.
9.1.3 Calibrate the strain transducer in accordance with the directions and fixtures
supplied with the apparatus.
9.1.4 Verify the overall calibration of the DSR using suitable reference fluids with
viscoelastic properties similar to asphalt binder. Do not attempt to verify individual load or
deflection detectors with a reference fluid. Suitable standards have not been identified.
NOTE6.--Reference fluids exhibiting moduli and phase angles within the range of measurement may be
used for verification purposes. Because reference fluids do not have the same temperature dependency as asphalt
binder, caution must be used when interpreting the results obtained from such fluids.
10. PREPARING SAMPLES AND TEST SPECIMENS
10.1 Preparing Test Samples--If unaged binder is to be tested, obtain test samples
according to T40.
10.1.1 Anneal the asphalt binder from which the test specimen is to be obtained by
heating until it is sufficiently fluid to pour the required specimens. Annealing prior to testing
removes reversible molecular associations (steric hardening) that occur during normal storage
at ambient temperature. Do not exceed a temperature of 163°C. Cover the sample and stir it
occasionally during the heating process to ensure homogeneity and to remove air bubbles.
Minimize the heating temperature and time to avoid hardening the sample.
NoTE 7.--Minimum pouring temperatures that produce a consistency equivalent to that of SAE 10W30
motor oil (readily pours but not overly fluid) at room temperature are recommended. Heating unaged asphalt to
temperatures above 135°C should be avoided. With some modified asphalts or heavily aged binders, however,
pouring temperatures above 135°C may be required.
10.1.2 Cold material from storage containers must be annealed prior to usage.
Structure developed during storage can result in overestimating the modulus by as much as
50%.
10.2 Preparing Test Specimens--Carefully clean and dry the surfaces of the test plates
so that the specimen adheres to both plates uniformly and strongly. Bring the chamber to
approximately 45 °C so that the plates are preheated prior to the mounting of the test
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