试验温度及针入度误差对沥青低温感温性指标的影响研究

The Study on the Effect of Experimental Temperature and Penetration Deviation on Low-Temperature Susceptibility Indexes of Asphalt

为了研究不同试验温度组合和针入度测量误差对沥青结合料低温感温性的影响,选用4种90号基质沥青和SBS改性沥青,测定沥青在不同温度时的针入度,得到针入度指数PI和脆点T1.2。结果显示,选用3个试验温度得出的PI和T1.2离散性较大,选用3个连续温度得出的结果离散性最小。与选用3个试验温度相比,选用4个或5个试验温度能很好地降低结果的离散性,对低温感温性的评价更客观。针入度较小的测量误差会引起针入度指数PI较大的变异,其中单独变化20℃时针入度引起的变异最小。

In order to research the effect of different experimental temperatures and measuring error of penetration on low-temperature susceptibility of asphalt binder, this paper selected four kinds of No.90 matrix asphalts and SBS modified asphalts, measured the penetration of asphalt under different temperatures with penetration index（PI） and breaking point T1.2 obtained. The result showed that the discreteness of PI and T1.2 got from the three selected experimental temperatures was large, while the discreteness of three consecutive experimental temperatures was minimum. Compared with the three selected experimental temperatures, selecting four or five experimental temperatures could reduce the discreteness well, which had more objective evaluation on low-temperature susceptibility. Measuring error with small penetration would cause big variation of PI. Among it,minimum variation was caused by penetration at 20 ℃.