基于流变学的SEBS/橡胶粉复合改性沥青低温性能研究

Low temperature performance of compound modified asphalt with SEBS and rubber powder based on rheology

为提高橡胶沥青在寒冷地区的路用性能,选用SEBS改性剂对橡胶沥青进行复合改性,在保持橡胶粉掺量一定的情况下制备不同SEBS掺量的复合改性沥青,通过弯曲梁流变仪(BBR)对沥青低温性能进行测定,并引入蠕变速率劲度比(m/S)和低温连续分级温度(TLC)对不同SEBS掺量的复合改性沥青低温性能进行评价.结果表明,SEBS改性剂可显著降低沥青蠕变劲度,使沥青低温柔性得到改善,且温度越低改善效果越明显;短期老化后复合改性沥青的柔性和应力松弛能力均未出现明显降低,表明短期老化后沥青仍能保持较好的低温性能,SEBS对沥青抗老化性能具有改善作用;掺加SEBS改性剂后,m/S值有所提高,低温连续分级温度显著降低,表明SEBS/橡胶粉改性沥青具有优越的低温性能,通过综合比选得出SEBS最佳掺量为6%.

In order to improve the road performance of rubber asphalt in cold regions,SEBS modifier was used to compound the rubber asphalt.The prepared composite modified asphalt with different SEBS content was tested when keeping the rubber powder content unchanged.The low temperature performance of asphalt was tested by bending beam rheometer (BBR),and the creep rate stiffness ratio ( m/S ) and low temperature continuous grading temperature ( T LC ) were introduced to evaluate the low temperature performance of composite modified asphalt with different SEBS content.Test results indicate that SEBS modifier could significantly reduce the creep stiffness of asphalt,thus improving the low temperature flexibility of asphalt.And the lower the temperature,the more obvious the improvement was.The flexibility and stress relaxation ability of the composite modified asphalt did not decrease significantly after short-term aging,indicating that the asphalt could maintain good low temperature performance after short-term aging,and SEBS could improve the anti-aging performance of asphalt.After adding SEBS modifier,the m/S value increased and the T LC value decreased significantly.Therefore,SEBS/rubber powder modified asphalt had superior low temperature performance.Through comprehensive comparison,the optimal content of SEBS was 6%.