NSiP改性沥青的流变性能及抗老化性能研究

Rheological properties and anti-aging properties of NSiP modified asphalt

为了研究纳米材料对沥青及沥青混合料的性能影响,采用掺量为0.2%、0.4%和0.6%的纳米二氧化硅粉末(NSiP)制备了改性沥青及沥青混合料。采用旋转黏度计和弯曲梁流变仪(BBR)分别评价改性沥青的高低温流变性能。基于MSCR试验中3.2kPa下的应变恢复百分比和BBR试验中的劲度模量指标,分别得到了短期老化和长期老化的老化因子,并对其进行拟合。此外,采用冻融劈裂试验评价了改性沥青混合料的水稳定性。结果表明,在0.2%、0.4%和0.6%的NSiP的改性条件下,经过0.4%NSiP改性后沥青的综合性能更好,NSiP粉末可以改善沥青的老化性能,MSCR老化指标和BBR老化指标很好的线形关系,改性沥青混合料的水稳定性有了显著提高。

To study the effect of nanomaterials on the performance of asphalt and its mixture,0.2%,0.4%,and 0.6%of nanosilicon dioxide powder(NSiP)were used to prepare modified asphalt and its mixture.Rotational viscometer and bending beam rheometer(BBR)were used to evaluate the high and low temperature rheological properties of modified asphalt.Based on the strain recovery percentage under 3.2 kPa in the MSCR test and the stiffness modulus index in the BBR test,the aging indexes of short-term aging and long-term aging were obtained and fitted.In addition,the freeze-thaw split test was used to evaluate the water stability of the modified asphalt mixture.The results show that under the modified conditions of 0.2%,0.4%,and 0.6%of NSiP,the comprehensive performance of asphalt after 0.4%NSiP modification is better.NSiP can improve the aging performance of asphalt.The MSCR aging index has a good linear relationship with the BBR aging index.Meanwhile,the water stability of the modified asphalt mixture has been significantly improved.