重度聚合物改性沥青蠕变恢复测试参数及评价准则

Creep and Recovery Test Parameters and Evaluation Criteria of Highly Polymer Modified Asphalt

为了比较常规掺量SBS改性沥青与重度SBS改性沥青蠕变恢复行为之间的差异,采用多应力蠕变恢复试验作为两种改性沥青的评价方法,研究多应力蠕变恢复试验参数变化对高温蠕变恢复行为的影响。采用旋转烧瓶法替代传统的旋转薄膜烘箱试验(RTFO)以使得高粘度的重度改性沥青老化更加均匀。结果表明,与常规掺量SBS改性沥青相比,当采用MSCR试验评估重度改性沥青时,其不可恢复蠕变柔量低估了应变响应,从而导致高估重度改性沥青所能适用的交通水平。此外,重度改性沥青的永久应变具有很强的加载时间依赖性,采用较短的加载时间更有利于减轻重复蠕变恢复对试验结果的影响。最终推荐采用0.1 s的加载、0.9 s的卸载组合,同时以3.2 k Pa下第10次蠕变恢复循环得到的Jnr值作为最终的评价参数。

In order to compare the difference between the conventional SBS modified asphalt and the creep recovery behavior of SBS modified asphalt,the multi-stress creep recovery test was used as the evaluation method of two kinds of modified asphalt to study the change of multi-stress creep recovery test parameter On the creep recovery behavior of high temperature.The rotary flask method was used instead of the conventional rotary film oven test（RTFO） to make the aging of the heavily modified asphalt aged more highly uniform.The results show that the unrecoverable creep compliance underestimates the strain response when using the MSCR test to assess the severe modified asphalt compared to the conventional SBS modified asphalt,resulting in overestimation of the traffic that can be applied for heavily modified asphalt level.In addition,the permanent strain of heavily modified asphalt has a strong loading time dependence,and the shorter loading time is more beneficial to reduce the effect of repeated creep recovery on the test results.It is recommended to use the loading of 0.1 s,the unloading combination of 0.9 s,and the Jnr value obtained by the 10 th creep recovery cycle at 3.2 k Pa as the final evaluation parameter..