AASHTO T316:2013 Standard Method of Test for Viscosity Determination of Asphalt Binder Using Rotational Viscometer.
10.1. The accuracy of the rotary transducer is checked using a reference fluid (Newtonian fluid) of known viscosity at various temperatures. The reference fluid shall be certified to be Newtonian in behavior over the full range of expected test temperatures and shear rates. The viscosity measured should be within ±2 percent or the rotary transducer requires recalibration.
10.2. The accuracy of the temperature reading of the temperature controller is checked by placing an asphalt sample in the testing chamber and equilibrating to a given temperature. The indicated temperature shall be verified by using a NIST -traceable measuring device as defined by ASTM E 1.
Preparing Test Sarnples—Unaged asphalt and modified asphalt binders are obtained according to T 40.
11.1.1. Anneal the asphalt binder from which the specimen is obtained by heating until sufficiently fluid to pour. Annealing prior to testing removes reversible molecular associations (steric hardening) that may occur during normal storage at ambient temperature.
Note 1—Minimum pouring temperature that produces a consistency equivalent to that of SAE I 0W30 motor oil (readily pours but not overly fluid) at room temperature are recommended. The specific temperature will depend on the grade of binder and its prior aging history, if any. Temperatures less than 135°C are desirable: however, temperatures above 135°C may be required for some modified asphalt binders or heavily aged binders.
12.1. Read and understand the information in the rotational viscorneter manufacturer’s operating manual before proceeding.
12.2. Turn on the rotational viscometer and proportional temperature controller unit.
12.3. Preheat the sample holder with the sample chamber and the selected cylindrical spindle according to the manufacturer’s recommendation.
12.4. Set the proportional temperature controller to desired test temperature.
12.5. 1 leat the required amount of asphalt binder as recommended by the manufacturer for testing according to Section 11.1.1.
1 2.6. When the proportional temperature controller reads the desired test temperature, remove the sample holder, and add the required amount of asphalt into the sample chamber.
12.7. Insert the sample chamber into the proportional temperature controller unit.
12.8. Insert a preheated spindle and attach it to the viscometer using the necessary coupling. Gently lower the spindle into the asphalt so that asphalt covers the upper conical portion of the spindle. This procedure may vary based on the manufacturer’s recommendations.AASHTO T316 pdf download.