TB胶粉复合SBS改性沥青及混合料的低温性能

通过小梁弯曲蠕变试验(BBR)以及半圆弯拉试验(SCB),对不同TB胶粉掺量和苯乙烯丁二烯苯乙烯嵌段共聚物(SBS)掺量的TB胶粉复合SBS改性沥青及其混合料的低温性能进行研究,并对其低温性能指标进行相关性分析.结果表明:与基质沥青相比,TB胶粉改性沥青具有优异的低温性能,且随着TB胶粉掺量的增加,其低温PG分级温度下降,沥青低温应力变小,混合料低温抗裂性增强;TB胶粉复合3%SBS改性沥青及其混合料的低温性能高于基质沥青,且随着TB胶粉掺量的增加,其低温性能改善效果较为显著,但低于相应掺量的TB胶粉改性沥青;随着SBS掺量的增加,10%TB胶粉复合SBS改性沥青的低温性能变化不明显,混合料的低温抗裂性变差;TB胶粉改性沥青的低温PG分级可以很好地反映沥青及其混合料的低温性能,而TB胶粉复合SBS改性沥青不能通过单一的PG分级来评价其低温性能,需要结合其他指标共同评价.

Low Temperature Performance of TB Crumb Rubber Composite SBS Modified Asphalt and Mixture

Bending beam rheometer test(BBR)and semi-circular bend test(SCB)were conducted to study the low temperature performance of terminal blend(TB)crumb rubber composite styrene-butadiene-styrene(SBS)modified asphalt and its mixture with different contents of TB crumb rubber and SBS.The correlation of different low temperature performance indexes was analyzed.The results show that compared with the matrix asphalt,TB crumb rubber modified asphalt has excellent low-temperature performance,and with the increase of the TB crumb rubber content,the low temperature PG of TB crumb rubber modified asphalt decreases,the thermal stress of asphalt decreases,and the low temperature crack resistance of mixture is enhanced;the low temperature performance of TB crumb rubber composite 3%SBS modified asphalt and its mixture is better than that of matrix asphalt,and with the increase of the TB crumb rubber content,the improvement effect of low temperature performance of composite modified asphalt is more significant,but is not better than that with the corresponding content of TB crumb rubber modified asphalt;with the increase of SBS content,the low temperature performance of 10%TB crumb rubber composite SBS asphalt does not change significantly,and the low temperature crack resistance of the mixture becomes poor;the low temperature PG grade of TB crumb rubber modified asphalt can well reflect the low temperature performance of asphalt and its mixture,while the low temperature performance of TB crumb rubber composite SBS modified asphalt can't be evaluated by a single low temperature PG index,which needs to be evaluated together with other indexes.