不同老化方式对沥青低温性能的影响分析

Analysis of effects of various aging techniques on asphalt low-temperature performance

研究了不同老化方式对沥青低温性能的影响,分3个阶段,对不同老化方式的试验结果进行了比较.阶段1研究表明,沥青在压力老化容器(PAV)中100℃条件下老化20 h后的低温性能与在1.01×105Pa、60℃条件下老化38 d后的低温性能相差无几.阶段2研究表明,可以通过58℃、10 r/s时的高温因子G*/sinδ来修正低温性能分级,从而可以利用短期老化来代替长期老化试验.阶段3研究表明,沥青的低温性能会随着老化时间改变而变化.当老化时间较短时,低温性能分级由劲度指标控制;当老化时间较长时,低温性能分级将转变为由蠕变速率控制.

The aim of this article is to investigate the effects of various aging techniques on asphalt low-temperature properties. The work was devided in Phase 1, it was shown that 38 days＇ to three phases, comparing different results obtain by various aging methods. In aging of asphalt at 60℃and 1. 01 × 10^5 Pa was approximately equivalent to 20 hour aging in the pressure-aging vessel （PAV）. Low-temperature properties of the samples were not significantly different between the PAV-and ordinary room-aged. In Phase Ⅱ , a correlation was developed from the high-temperature factor G^＊/sinδ and obtained equivalent to some low-temperature performance grade using such accelerating aging procedure. In Phase Ⅲ, it was shown that as asphalts were aged for extended periods, their Low-temperature properties might change. Furthermore, the longer the extended periods were the low-temperature grades apeared to move from being determined limited by stiffness to by creep rate.