灰色预测方法在沥青混合料永久变形研究中的应用

Application of Grey Forecast Method in Bitumen Mixture Permanent Deformation Study

通过高温下沥青混合料蠕变试验发现,加载30min时滞后弹性变形基本完成,可以近似认为其后发生的变形为粘性变形,从而利用灰色预测模型,对加载过程中30min至60min的变形数据进行逆向拟合,得到整个加载过程中的永久变形方程。然后利用坐标变换,得到了时间序列下沥青混合料的永久变形规律。相比于常规的数据拟合方法,由于采用了加载后段的数据进行拟合,避免了开始加载过程中虚假变形的影响,使得拟合的结果更加准确。

It was found that in creep test the elastic strain of asphalt mix would complete in thirty minutes.It could be concluded that the deformation from 30th minute to 60th minute is almost permanent.By use of the grey method it is possible to get the permanent deformation equation of asphalt mix,and by coordinate transformation to get the law of permanent deformation with time.Compared with the normal data simulation method,because of using the data at latter stage of loading the effect of initial virtual deformation can be avoidable,the grey method may get more accurate result.