改性沥青低温性能评价指标研究

鉴于目前国内外没有公认的、比较合理的改性沥青低温性能评价指标,运用灰色关联理论建立常用改性沥青低温性能评价指标和沥青混合料低温性能的关联性。依据试验中各种评价指标与沥青混合料低温性能关联度的排序结果,得到临界开裂温度与沥青混合料低温性能的关联度最好,接下来依次是SHRP低温分级、粘温系数m和低温损失模量,而沥青的低温针入度、延度和当量脆点、弯曲应变能与沥青混合料低温性能的关联度都较小。结果表明,在评价改性沥青低温性能时,采用粘弹指标比常规指标能更好地反映改性沥青的低温性能。

Study on the Low Temperature Performance Evaluation Indexes of Modified Asphalt

There are many methods to evaluate the low temperature performance of modified asphalt,but there are no accepted and reasonable evaluation methods.As a result,these evaluation methods are compared,and theory of the grey correlation is used to evaluate the correlation of asphalt evaluation method and asphalt mixture low temperature performance.The results show that the sequence from high to low of correlation degree is critical fracture temperature,SHRP low temperature grade,viscosity temperature coefficient m and low temperature loss modulus.Low temperature penetration,ductility and breaking point have the lowest correlation degree with asphalt mixture low temperature performance.Therefore it is more reasonable to adopt viscoelastic properties evaluations than general evaluations.