Softening point test procedures for a long time recommended - Database & Sql Blog Articles

Step 1: Prepare the sample. Ensure that the sample is slightly higher than the torus. Allow it to cool at room temperature for 30 minutes, then secure the sample ring using a clamp ring. Use a hot scraper to remove excess material from the torus, making sure it's level with the ring.

Step 2: Place the sample, metal bracket, steel ball, and positioning ring into a constant temperature water bath maintained at 5°C ± 0.5°C for at least 15 minutes. This ensures uniform thermal conditions before testing.

Step 3: Fill a beaker with freshly boiled water and allow it to cool down to 5°C. Make sure the water level is slightly above the depth mark on the pole to ensure proper immersion during the test.

Step 4: Remove the sample from the water bath and place it in the central hole of the bracket’s middle layer. Position the steel ball positioning ring and carefully lower the entire assembly into the beaker. Adjust the water level to align with the depth mark.

Step 5: Transfer the beaker to a heater equipped with an asbestos net. Start the stirrer and begin heating. The temperature should rise at a controlled rate of 5°C ± 0.5°C per minute for the first 3 minutes. Record the temperature increase accurately every minute.

Step 6: As the sample heats up, it will gradually soften, causing the steel ball to descend. When the ball touches the surface of the lower plate, immediately record the temperature to the nearest 0.5°C. This value represents the softening point of the sample.

If the estimated softening point is above 120°C, preheat the sample ring and bottom plate (without the glass plate) to 80–100°C before pouring the asphalt sample. Once cooled for 30 minutes, use a hot scraper to trim the sample to match the annulus exactly.

Folding Test Procedure

For samples with a softening point below 80°C:

a. Place the sample ring along with the bottom plate in cold water (5°C ± 0.5°C) for at least 15 minutes. At the same time, immerse the metal bracket, steel ball, and positioning ring in the same water bath.

b. Fill a beaker with fresh boiling water and let it cool to 5°C. Ensure the water level is slightly below the depth mark on the pole.

c. Carefully transfer the sample ring from the bath and place it in the central hole of the bracket’s middle plate. Add the positioning ring and submerge the entire assembly in the beaker. Adjust the water level to the depth mark. Insert a thermometer vertically through the center hole of the upper plate so that the sensing tip is flush with the bottom of the sample ring. No air bubbles should be present on any part of the ring.

d. Move the beaker to the heater with an asbestos net. Place the steel ball in the center of the sample within the positioning ring and start heating. Maintain a temperature increase of 5°C ± 0.5°C per minute for 3 minutes. If the temperature rises too quickly, the test must be repeated.

e. As the sample softens, the steel ball will gradually fall. When it touches the lower substrate, record the temperature immediately to the nearest 0.5°C.

For samples with a softening point above 80°C:

a. Place the sample ring with the sample and bottom plate in a glycerin bath maintained at 32°C ± 1°C for at least 15 minutes. Immerse the metal bracket, steel ball, and positioning ring in the same bath.

b. Pour preheated glycerin (32°C) into the beaker, ensuring the level is slightly below the depth mark on the pole.

c. Follow the same procedure as in step (1), but this time record the temperature to the nearest 1°C.

Folding Report

The test should be conducted in duplicate using the same sample. If the difference between the two results meets the repeatability requirements, take the average as the final result. The softening point should be reported to the nearest 0.5°C.

Folding Precision or Tolerance

(1) For samples with a softening point below 80°C, the allowable difference for repeatability is 1°C, and for reproducibility, it is 4°C.

(2) For samples with a softening point equal to or greater than 80°C, the allowable difference for repeatability is 2°C, and for reproducibility, it is 8°C.