基于动态剪切流变试验的沥青高温性能评价

Evaluation on High Temperature Performance of Asphalt Based on Dynamic Shear Rheological Test

摘要:

沥青的高温稳定性作为沥青路面材料设计的输入参数之一，能够保证沥青路面使用寿命内不发生严重车辙病害。为了探究沥青的高温黏弹性行为，选取三种基质沥青和两种改性沥青，利用动态剪切流变仪（DSR）对其高温性能进行测试。对比了不同沥青的软化点、PG高温分级结果和多应力重复蠕变试验（MSCR）实验结果的一致性。试验结果表明，采用不同实验所得的结果具有一致性，改性沥青的高温性能优于基质沥青。改性沥青的软化点、车辙因子（G*/sin δ）和蠕变回复率（R）均大于基质沥青，而不可回复蠕变柔量（Jnr）小于基质沥青。此外，基于DSR的测试指标相比针入度和软化点能够更好地表征沥青的黏弹性性能，并且更好地模拟在实际路面上车辙的产生发展过程。

Abstract:

As one of the input parameters for the design of asphalt pavement material, the high temperature stability of the asphalt can ensure the serious rut disease not occurring within the service life of asphalt pavement. In order to explore the high temperature viscoelasticity of asphalt, three matrix asphalts and two modified asphalt are selected. The dynamic shear rheometer (DSR) is used to test its high temperature performance. The consistency of softening points, PG high temperature grading results and multiple stress creep recovery (MSCR) test results of different asphalts is compared. The result shows that the results obtained by using the different experiments have the consistency. The high temperature performance of the modified asphalt is better than the matrix asphalt. The softening point, rutting factor ( G*/sin δ ), and creep recovery percent (R) of modified asphalt are higher than the matrix asphalt, and the non-recoverable creep compliance (Jnr) are lower than the matrix asphalt. Additionally, the test index based on DSR can better express the viscoelasticity property of the asphalt by comparing with the needle penetration and softening point, and can better simulate the rutting development process on the practical pavement.