测试条件对SBS改性沥青表观黏度影响研究

On the Effect of Testing Conditions on the Apparent Viscosity of SBS Modified Asphalt

黏度是沥青的一项重要性质,与沥青混合料施工温度和施工和易性密切相关,为了评价测试条件对黏度的影响,采用布洛克菲尔德黏度计,研究了不同时间、温度和转速条件下SBS改性沥青表观黏度变化情况.结果表明:SBS改性沥青表观黏度值随时间增加逐渐趋于稳定,温度越高、剪切速率(转速)越大,黏度趋于稳定的时间越短,且初始黏度与稳定黏度之间的差值越小;当温度超过150℃时,黏度与转速无关;不同温度下进行SBS改性沥青黏度测定时,转速应不小于20 r/min.

Viscosity is an important property of asphalt,and has a close relationship with the construction temperature and workability of the asphalt mixtures. In order to evaluate the effect of testing conditions on the viscosity,the apparent viscosity of SBS modified asphalt under different times,different temperatures,and different shear rates is studied by using Brookfield viscometer. The results shows that the apparent viscosity of SBS modified asphalt is tending towards stability with time increasing gradually. The higher the temperature and the greater the shear rate,the shorter the time for viscosity stabilizing and the smaller the difference between the initial viscosity and stable viscosity. When the testing temperature exceeds 150 ℃,the variation of shear rate has little effect on the viscosity. The shear rate should be no less than 20 RPM when the viscosity of SBS modified asphalt is measured at different temperatures.