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Liu Z.,Central South University | Liu Z.,Hunan Zhili Engineering Science and Technology Co. | Niu Y.,Central South University | Xiao J.,Central South University | And 4 more authors.
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | Year: 2015

Considering that the lack of a method to dynamically monitor the SBS content in modified asphalt is becoming a barrier to the quality control of the SBS modified asphalt, a rapid and quantitative detection method based on potentiometric titration was developed. The basic procedures were as follows: A series of modified asphalt solution with determined SBS content was mixed with Wijis reagents. After two hours of reaction at constant temperature of (35±2)℃, 3 min reaction of the mixture with potassium iodide solution was conducted to transfer the left Wijis reagents to iodide. Then a redox titration was realized by dropping sodium thiosulfate standard solution, and the potentiometric titration analysis was applied to acquire the reaction end point. The results show that there is a good linear function between the SBS content and the volume of sodium thiosulfate solution consumed by the SBS modified asphalt. In this way, the SBS content in an unknown sample solution can be calculated accurately by its depletion of sodium thiosulfate solution. The potentiometric titration can eliminate the side effects existing in the conventional chemical titration caused by deep color background of asphalt and the possible aggregation of asphalt during titration, and produce rapid titration result with the precision less than 0.5% relative tolerance. ©, 2015, Central South University of Technology. All right reserved. Source

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