材料期刊网

为评价不同改性沥青(SBS 改性沥青(SMA)、橡胶粉改性沥青(RPMA)、复合改性沥青(CMA))老化前后的温度敏感性,利用动态剪切流变仪对以上3种改性沥青老化前后的试样进行动态剪切流变实验,并取老化前后温度扫描数据利用粘温指数VTS 的不同算法在不同温标下对改性沥青的粘度-温度曲线进行拟合,针对不同沥青从线性相关系数的角度分析了各自最适用的温标及算法；在适用的温标下利用粘温指数 VTS 评价了不同改性沥青老化前后的温度敏感性,并利用电子显微镜扫描实验,从沥青的微观结构特征分析了不同改性沥青温度敏感性存在差异的原因。结果表明,在开式温标及兰金式温标下拟合出的 VTS 可以更好地评价不同改性沥青的温度敏感性；组分及蜡含量的变化对改性沥青温度敏感性影响最大,胶体结构与大分子分子量的影响次之；老化作用使改性沥青温度敏感性降低,RPMA 在老化前后温度敏感性最低。

To evaluate the temperature susceptibility of different kinds of modified asphalt(SBS modified asphalt (SMA),rubber powder modified asphalt (RPMA),composite modified asphalt (CMA))before and after short-term aging,the dynamic shear rheometer test was conducted for the samples of them before and after aging, then the aging temperature scanning data were taken for linear regression of viscosity-temperature curve using different algorithms under the different temperature scales,according to the result of regression,the viscosity-temperature exponent -VTS can be obtained.The most suitable scale and algorithm were analyzed from the view of linear correlation coefficient,and the temperature susceptibility of different kinds of modified asphalt were evaluated usingVTS under the different temperature scales.Next,the reason why different polymer modi-fied asphalt have different temperature susceptibilities was analyzed from the microstructure of asphalt using scanning electron microscopy (sem)test.Results showed that:the VTS fitted under the kelvin scale and Ran-kine scale can evaluate the temperature susceptibility of different modified asphalt more appropriate,the influ-ence of the changes of components and wax is the biggest of all,followed by the influence of colloid structure and molecular weight,short-term aging decreases the temperature susceptibility of modified asphalt,rubber powder modified asphalt has the lowest temperature susceptibility before and after aging.