PE+SiO_(2)复合改性沥青储存稳定性多尺度研究

Multi-scale research on storage stability of PE+SiO_(2) composite modified asphalt

为了提高普通塑料(PE)改性沥青的热储存稳定性,提出在PE改性沥青中添加纳米二氧化硅(SiO_(2))粒子,以制备PE+SiO_(2)复合改性沥青,并基于宏、微观试验,结合图像处理和灰色关联熵等定量分析方法,揭示了不同类型PE+SiO_(2)复合改性沥青的储存稳定性、高低温性能、微观组分与结构形貌差异,得到了其特征官能团指数和改性剂分布指数与各项宏观性能之间的关联,确定了最佳PE类型和SiO_(2)掺量.结果表明:复合改性沥青中SiO_(2)和PE组分之间发生了物理交互连锁反应,使沥青高温稳定性和储存稳定性得以提升,且尤以线型低密度聚乙烯(LLDPE)型复合改性沥青的效果最优;SiO_(2)掺量为0.2%时,改性剂分散较好,荧光面积占比适中,软化点差最小,离析率最低,各项指标的关联较为均匀,为最佳掺量.研究成果可为高性能复合改性沥青的生产制备提供参考,为改性沥青多尺度特性的研究提供新视角.

In order to improve the thermal storage stability of traditional polyethylene(PE)modified asphalt,the PE+nano silica dioxide(SiO_(2))composite modified asphalt binder was prepared by adding SiO_(2)particles into PE modified asphalt.The storage stability,high and low temperature performance,microscopic components and structural morphology differences of these different types of PE+SiO_(2)composite modified asphalt were revealed based on macro and micro tests,combined with quantitative analysis methods such as image processing and gray correlation entropy.The correlation between the characteristic functional group index and modifier distribution index and various macroscopic properties was obtained.The appropriate PE modifier and the optimal content of SiO_(2)were determined.The experimental results showed that SiO_(2)and PE in the composite modified asphalt had an interactive chain reaction,which improved the storage stability and high-temperature performance of the asphalt,and the best effect was realized especially for the linear low density polyethylene(LLDPE)composite modified asphalt.When the content of SiO_(2)was 0.2%,the modifier was well dispersed,the proportion of fluorescent area was moderate,the softening point difference was minimal,the segregation rate was the lowest,and the correlation of indexes was relatively uniform.Therefore,the optimum content of SiO_(2)was 0.2%.The research results would provide reference for the preparation of high performance composite modified asphalt and the study of multi-scale characteristics of modified asphalt.