THFS改性沥青的抗老化性能

Anti-aging properties of THFS modified asphalt

为研究四氢呋喃可溶物(tetrahydrofuransoluble,THFS)改性沥青的抗老化性能,采用RTFOT对不同THFS掺量(0%、4%、6%、8%、10%)的改性沥青进行老化,利用软化点增量(softening pointincrement,SPI)、黏度老化指数(viscosity agingindex,VAI)、残留针入度比(residual penetration ratio,RPR)、残留延度(residual ductility,RD)以及老化前、后的羰基峰面积比值从宏、微观角度分析其抗老化性能。利用Pearson系数法建立THFS改性沥青微观结构与宏观性能之间的相关性。以THFS改性沥青的软化点为参数建立老化动力学方程,分析老化过程的反应速率和活化能。结果表明:THFS改性沥青的SPI、VAI、RPR、羰基峰面积比值与THFS掺量成良好的线性关系,随着THFS掺量的增加,沥青的羰基浓度、SPI、VAI和反应速率逐渐增大,RPR、RD和活化能逐渐降低,说明沥青的抗老化性能越来越差,其中,THFS改性沥青老化前、后的羰基峰面积比值与SPI的相关性最大。当THFS掺量在6%以内时,THFS改性沥青的SPI、VAII、RPR、反应速率及活化能变化幅度相对较小,因此,建议THFS掺量控制在6%以内。

In order to study the anti - aging properties of tetrahydrofuran soluble （THFS） modified as- phalt, RTFOT was used to age the modified asphalt with different THFS contents （0%, 4%, 6%, 8%, 10% ） in this paper. Softening point increment （SPI）, viscosity aging index （ VAI）, residual penetration ra- tio （ RPR）, residual ductility （ RD）, the ratio of carbonyl peak area before and after aging were applied to a- nalysis the anti -aging properties from macro and micro perspectives. Meanwhile, the correlation between mi- crostructure and macroscopic properties of THFS modified asphalt was established by Pearson coefficient meth- od. Furthermore, the softening point was used as the parameter to establish the aging kinetic equation for ana- lyzing the reaction rate and activation energy of aging process. The results showed that the linear relation be- tween SPI, VAI, RPR, carbonyl peak are a ratio and the THFS content was good. With the increase of THFS contents, the carbonyl concentration, SPI, VAI and reaction rate of asphalt increased, but the RPR, RD and activation energy decreased gradually, which indicated that the anti - aging properties of asphalt became worse and worse. Additionally, the correlation between the carbonyl peak area ratioand SPI was best. The change ranges of SPI, VAI, RPR, reaction rate and activation energy were relatively small when THFS content was less than 6%, therefore, the THFS content was recommended as 6%.