沥青感温性能评价指标

为了选择合理的沥青感温性能评价指标, 分别采用15、25、30℃的针入度与25℃的针入度和软化点计算了沥青针入度指数, 用以评价2种普通沥青、3种改性沥青的感温性, 用动态剪切流变仪测得不同温度条件下几种沥青的动态复数粘度, 分析其粘-温关系。研究结果表明: 普通沥青粘-温关系在15~60℃范围内有较好的线性关系, 其温度敏感性是常数, 改性沥青的粘-温关系较好地满足WLF方程, 其温度敏感性随温度而变化, 因此, 普通沥青感温性能用针入度指数表示, 改性沥青感温性能评价需要指定温度条件。

Evaluation index of temperature susceptibility for asphalt

To choose the reasonable evaluation index of temperature susceptibility for asphalt, the penetration indices of asphalt were calculated through the penetrations at 15, 25 and 30 ℃ and the penetration and softening point at 25 ℃ respectively, they were applied to evaluate the temperature susceptibilities of two kinds of common asphalts and three kinds of polymer modified asphalts(PMA), the dynamic complex viscosities of the asphalts under different temperature conditions were tested by using dynamic shear rheometer, and their relationships between viscosity and temperature were analyzed. Analysis result shows that there are linear correlations between viscosity and temperature for normal bitumens within 15~60 ℃, their temperature susceptibilities are a constant, while the relationships of viscosity and temperature for PMA satisfy WLF equation, their temperature susceptibilities change with temperature. So the temperature susceptibility of common asphalt may be expressed by using penetration index, but temperature condition must be appointed to estimate the temperature susceptibility of PMA.