Instructions for using the Asphalt Dynamic Viscometer Viscometer

SYD-0620 Asphalt Dynamic Viscometer (Vacuum Reduced Pressure Capillary Method)

This method is applicable for determining the dynamic viscosity of viscous petroleum asphalt using a vacuum depressurization capillary viscometer. Unless otherwise specified, the test temperature is 60 ℃ and the vacuum degree is 40kPa.

[Instruments and Materials]

1. Vacuum pressure reducing capillary viscometer: a set of 3 capillary tubes, the shape of which is shown in Figure 1, and the model and size are shown in Table 1.

2 thermometers: 50 ℃~100 ℃, with a division of 0.1 ℃

3 Constant temperature water bath: made of hard glass, its height should be such that when the viscometer is placed, the highest time mark should be at least 20mm below the liquid level. It is equipped with a heating and temperature automatic controller, which can keep the water temperature at the test temperature of 0.1 ℃, and has a stirrer and clamping device. The temperature difference at different positions in the sink shall not exceed 0.1 ℃. The temperature control precision of the insulation device should reach 0.1 ℃.

4. Vacuum pressure reduction system: The vacuum degree reaches a pressure of 40kPammHg ± 66.5Pa (300mmHg ± 0.5mmHg), and the schematic diagram of the entire device is shown in Figure 2. There should be no air leakage at each connection to ensure airtightness. When opening the capillary pressure reducing valve for measurement, there should be no negative pressure reduction. Connect a vacuum pump at the open end to evacuate.

5 stopwatches: 2, with a division of 0.1s, and a total range error of no more than ± 0.05% within 15 minutes.

[Method and Steps]

preparation

Estimate the viscosity of the sample and select the model of vacuum capillary viscometer based on the time it takes for the sample to flow through the specified volume for at least 60 seconds.

Wash the vacuum capillary viscometer thoroughly with solvents such as trichloroethylene. If the viscometer has oil stains, it can be carefully washed with detergent, distilled water, etc. After washing, dry in an oven or blow dry with hot air through cotton.

Prepare asphalt samples according to T0602 of this regulation, and carefully heat the dehydrated and sieved samples to a fully flowing state. During heating, stir appropriately to ensure even heating. Then pour the sample into another small container that is convenient for filling into the capillary tube, with a quantity of 50ml each, and cover it with a lid.

Heat the sink and adjust the temperature to within the range of 60 ℃± 0.1 ℃. The thermometer should be pre calibrated.

Heat the selected vacuum capillary viscometer and sample in an oven (135 ℃± 5 ℃) for 30 minutes.

4 Experimental Steps

Place the heated viscometer in a container, and then inject the hot asphalt sample from tube A into the capillary viscometer

The sample should not stick to the pipe wall and the liquid level of the sample should be within ± 2mm of the E-line. Place the capillary viscometer with the loaded sample back into the oven (135 ℃± 5.5 ℃) and keep it warm for 10 minutes ± 2 minutes to allow the bubbles generated by the sample in the tube to escape.

Take out 3 capillary viscometers from the oven, cool them at room temperature for 2 minutes, and install them in a constant temperature water bath that maintains the test temperature. The position should be such that the I-line is at least 20mm below the liquid level in the bath. The operation time from taking out the viscometer from the oven to placing it in the constant temperature water bath should be controlled within 5mm.

Connect the vacuum system to the viscometer, start the vacuum pump or vacuum pump to achieve a vacuum degree of 40kPa (300mmHg ± 0.5Hg).