基于BBR与延度试验沥青低温性能对比研究

BASED ON BBR AND DUCTILITY TEST ASPHALT LOW TEMPERATURE PERFORMANCE COMPARISON STUDY

延度试验和BBR弯曲梁蠕变试验同时作为评价沥青低温性能的指标,两者得到的试验结果都是正确且具有参考价值的,但是两者试验结果存在不符合的情况。设想延度试验和BBR弯曲梁蠕变试验的试验结果存在某种逻辑关系,通过BBR弯曲梁蠕变试验与延度试验对不同沥青低温性能对比研究,分析试验结果的关系,得出两者试验同种沥青相对低温性能表现存在较大差异甚至结果相反的现象。进一步分析得到影响延度试验与BBR试验结果关系的深层因素,是由于不同沥青蠕变劲度模量变化率m、两者试验原理和加载形式,以及延度试验的塑性模型与BBR沥青梁线黏弹型模型及模型受力状态的不同导致了评价的差异。

Ductility tests and Bending beam rheological(BBR)tests are both used as indicators to evaluate the low temperature performance of asphalt,and the test results obtained are correct and of reference value,but there is a non-conformity between the two test results.It is assumed that there is a certain logical relationship between the re⁃sults of the ductility tests and BBR tests,and the low temperature performance of different asphalt is compared and studied by the two tests,in which the relationship between the results is analyzed.It is concluded that there is a large difference,or even the opposite result of the relative low temperature performance of the same kind of asphalt in the two tests.Further analysis of the deep factors affecting the relationship between the ductility test and the BBR test results are due to the difference in the rate of change of the modulus of the creep strength of different asphalt,the principle and loading form of the two,the difference in evaluation between the plastic model of the ductility test and the line viscoelastic model of the asphalt beam of the BBR tests,and the force state of the models.