Views:6 Author:Daisy Tao Publish Time: 2021-10-19 Origin:Site
What is Softening Point of Bitumen?
Softening Point of Bitumen:
Under the conditions of the ring and ball method(ASTM D36), the temperature at which the bitumen is softened by heating, deformed under the specified weight of the steel ball and dropped to a lower deck with a distance of 25.4 mm, is called the softening point of bitumen, expressed in degrees Celsius.
Why should the inner hole of the brass ring of the softening point tester be made into a cone shape with a large top and a small bottom?
The softening point tester is made of brass. The inner diameter of the ring is made into a cone shape with a large upper and a lower diameter. The main reason is to prevent samples with low adhesion to the metal surface from falling from the ring.
What are the factors that affect the determination of the softening point of bitumen?
(1) The Softening Point Ring and Ball Apparatus does not meet the requirements, which will affect the measurement results. Therefore, it is required to check the instrument:
The weight of the steel ball
The distance between the middle bearing plate and the lower bearing plate.
Whether the plane of each ring is in a horizontal state.
The thermometer should be calibrated.
(2) When melting bitumen samples, exceeding the allowable heating temperature and prolonged heating will affect the measurement results. Because the higher the heating temperature, the more intense the evaporation and oxidation of the oil in the asphalt will be, and the bitumen components will change (usually the oil and gum content will decrease, and the asphaltene content will increase), which will change the asphalt properties and soften it. Therefore, when the sample is required to be melted, the heating temperature should not be higher than the estimated softening point of the sample at 100 degrees Celsius, and the sample is not allowed to be heated for a long time.
(3) The heating rate is one of the main factors that affect the measurement results. If the heating is too fast, the measured softening point is higher, and vice versa.
Hot Softening Point Ring and Ball Apparatus for your reference.