Time Response-Based Synchronous Calibration of the Pavement Asphalt Softening Point Tester

Abstract

Abstract The asphalt softening point reflects the temperature sensitivity and high-temperature stability of asphalt pavement and is an important quality assessment indicator of asphalt pavement. The detection method of asphalt softening point commonly used in China is the asphalt softening point ring and ball tester. In JJG 057-2004 Vertification Regulation of Apparatus for Softening Point of Bitumen, the partial calibration method of the tester was proposed. The partial calibration method cannot realize the synchronous calibration of softening point and various definitions of the softening point are significantly different. Therefore, in order to achieve synchronous calibration of the asphalt softening point tester, a standard verification device was established in this study to simulate asphalt dropping and record response time and temperature simultaneously. The circuit composition, working principle, main technical indicators and influencing factors of key devices were explored and the uncertainty of response results obtained in warming water was evaluated. The evaluation results showed that it was feasible to realize the synchronous calibration of asphalt softening point tester with the verification device.