The softening point of asphalt refers to the temperature at which asphalt changes from a solid to a liquid state under certain conditions. It is one of the important indicators for evaluating the deformation resistance and heat resistance of asphalt, and a key indicator for characterizing the high-temperature performance of asphalt materials, serving as a core indicator for assessing their high-temperature stability.
The asphalt softening point tester follows the ring and ball method (or ring and ball method) principle. Its design and manufacture comply with the requirements of the People's Republic of China standard GB/T 4507 "Determination of Softening Point of Petroleum Asphalt" and the People's Republic of China industry standard JTG E20 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" T 0606 "Asphalt Softening Point Test (Ring and Ball Method)".
During the test, molten asphalt is first poured into a brass ring of specified size, cooled, and the surface is smoothed. The ring containing the sample is placed on a support frame, with a steel ball of specified mass (usually 3.5g ± 0.05g) and diameter (9.53mm) placed in the center of the ring. The assembly is then suspended in a beaker containing a heating medium (water or glycerol). After the instrument is started, the heating system raises the temperature of the medium at a constant rate, and the magnetic stirrer ensures uniform temperature. The heating rate is precisely controlled at (5.0±0.5)℃/min by a microcomputer controller (using PID, fuzzy logic, or interpolation algorithms, etc.).