Viscosity Evaluation Index of Hot-Applied Sealant for Asphalt Pavement

The relationship of viscosity to temperature is one of the most important factors in the application of hot-applied sealants. However, the present evaluation system cannot fully reflect the field performance of the sealants, given the lack of consideration of application conditions. A rotational viscometer and Rotor SC4-27 were used in this study to test the viscosity of hot-applied sealants, with viscosity at 50% torsional moment taken as the apparent viscosity. Nine kinds of sealants were tested in the temperature range of 160 degrees C to 200 degrees C. Analysis also was conducted to evaluate the correlation of the viscosity index with other indexes. The results showed no obvious correlation between them. Thus the viscosity index proposed in this study could be included in the present evaluation system in which the recommended pour temperature is 190 degrees C, and the rotational viscosity is in the range of 1 to 3 Pa-s.