基于WLF公式确定DSR中不同平行板的温度适用范围

Ascertaining Temperature Applying Range for Different Parallel Plates in Dynamic Shear Rheometer Based on WLF Equation

动态剪切流变仪不仅可以用来对沥青的路用性能进行分级,也可以在大温度范围内测定沥青的性能。采用动态剪切流变仪对沥青材料进行试验时,不同平行板在相同试验条件下对同种试样进行试验的数据不一定相同,并且不同半径的平行板有各自的温度实用范围,本文从时间温度等效原理入手,采用数据分析软件,对采用不同平行板进行试验得到的频率-模量曲线进行拟合,从而得到模量主曲线,确定出不同平行板的试验结果在一定频率范围内的互用范围。采用WLF公式计算出不同温度条件下对应的基准温度TS值,研究结果表明:在沥青模量一定的范围内,8 mm平行板与25 mm平行板相比更适合20℃以下的动态剪切试验,而在20℃以上,二者可以互用,这对于以后的研究提供了不同条件下选择仪器的一个参考。

Dynamic Shear Rheometer （DSR） not only can be used to determine road performance grade of asphalt, but also used to measure asphalt＇s capability in a large temperature range. Choosing different parallel plates from dynamic shear rheometer for making same test on same samples may get different experimental data. Starting data analysis with time-temperature equivalent principle to fit frequencycomplex module curves, module master curve is got, then that experimental data gained by the two different parallel plates can be substituted for each other in a certain frequency range. The bench mark temperature values Ts which are corresponding to different temperature by WLF equation are calculated. The results show 8 mm parallel plate is better than 25 mm parallel plate used below the 20 degree while in the high temperature they can be substituted.