ASTM D36 for softening point of bitumen (Ring-and-Ball apparatus)
ASTM D36 standard test method for softening point of bitumen (Ring-and-Ball apparatus)
5. Apparatus
5.1 Rings - Two square-shouldered brass rings conforming to the dimensions shown in Fig. 1(a).
5.2 Pouring Plate - A flat, smooth, brass plate approximately 50 by 75 mm (2 by 3 in.).
5.3 Balls - Two steel balls, 9.5 mm (3/8 in.) in diameter, each having a mass of 3.50 6 0.05 g.
5.4 Ball-Centering Guides - Two brass guides for centering the steel balls, one for each ring, conforming to the general shape and dimensions shown in Fig. 1 (b).
5.5 Bath - A glass vessel, capable of being heated, not less than 85 mm in inside diameter and not less than 120 mm in depth from the bottom of the flare.
NOTE 1 - An 800-mL, low-form Griffin beaker of heat-resistant glass meets this requirement.
5.6 Ring Holder and Assembly - A brass holder designed to support the two rings in a horizontal position, conforming to the shape and dimensions shown in Fig. 1 (c), supported in the assembly illustrated in Fig. 1 (d). The bottom of the shouldered rings in the ring holder shall be 25 mm (1.0 in.) above the upper surface of the bottom plate, and the lower surface of the bottom plate shall be 16 more or less 3 mm (5/8 more or less 1/8 in.) from the bottom of the bath.
5.7 Thermometers:
5.7.1 An ASTM Low Softening Point Thermometer, having a range from -2 to +80°C or 30 to 180°F, and conforming to the requirements for Thermometer 15C or 15F as prescribed in Specification E 1.
5.7.2 An ASTM High Softening Point Thermometer, having a range from 30 to 200°C or 85 to 392°F, and conforming to the requirements for Thermometer 16C or 16F as prescribed in Specification E 1.
5.7.3 The appropriate thermometer shall be suspended in the assembly as shown in Fig. 1 (d) so that the bottom of the bulb is level with the bottom of the rings and within 13 mm (0.5 in.) of the rings, but not touching them or the ring holder. Substitution of other thermometers shall not be permittted.
6. Reagents and Materials
6.1 Bath Liquids:
6.1.1 Freshly Boiled Distilled Water.
NOTE 2 - The use of freshly boiled distilled water is essential to avoid trapping air bubbles on the surface of the specimen which may affect the results.
6.1.2 USP Glycerin, or
NOTE 3 - Caution: Glycerin has a flash point of 160°C (320°F) in accordance with Test Method D92.
6.1.3 Ethylene Glycol, with a boiling point between 195 and 197°C (383 and 387°F).
NOTE 4 - Caution: Ethylene glycol is toxic when taken internally or inhaled as a vapor. Avoid prolonged or repeated skin contact and inhalation of vapors. Its flash point is 115°C (239°F) in accordance with Test Method D92. When using this bath liquid, conduct the test in a vented laboratory hood with adequate exhaust fan capacity to ensure removal of toxic vapors.
6.2 Release Agents:
6.2.1 To prevent adhesion of bitumen to the pouring plate when casting disks, the surface of the brass pouring plate may be thinly coated just before use with silicone oil or grease (Note 5), a mixture of glycerin and dextrin, talc, or china clay.
NOTE 5 - Caution: Isolate silicones from other bituminous testing equipment and samples to avoid contamination, and wear disposable rubber gloves whenever handling silicones or apparatus coated with them. Silicone contamination can produce erroneous results in other tests such as those for penetration and flash point.
