SBS类改性沥青低温性能评价及指标相关性分析

Evaluation of Low Temperature Performance and Correlation Analysis on Low Temperature Indexes of SBS Modified Asphalts

通过25℃针入度试验、5℃延度试验和小梁弯曲蠕变试验(BBR),对15种沥青进行低温性能评价和排序,并通过输出Person相关系数和线性拟合,对25℃针入度、5℃延度与PG低温分级温度进行相关性分析.结果表明:SBS类改性沥青的低温性能较基质沥青有不同程度的提升,其中TB+SBS类复合改性沥青以及高掺量橡胶粉沥青的低温性能最为优异;5℃延度同PG低温分级温度的相关性很低,说明用5℃延度来评价SBS类改性沥青低温性能存在局限性;25℃针入度与PG低温分级温度的相关性比5℃延度与PG低温分级温度的相关性高,25℃针入度与改性沥青低温性能的相关性有待进一步研究.

Low temperature performance and correlation between PG index and 25 ℃ penetration, as well as PG index and 5 ℃ ductility of SBS modified asphalts was evaluated by outputting Person coefficients and linear fitting. The results show that low temperature performance of SBS modified asphalts is improved compared with matrix asphalts, TB＋ SBS modified asphalts and rubber powder modified asphalts with high proportion of rubber powder could reach the best low temperature performance. 5 ℃ ductility has a very low correlation degree with PG index, which is limited to evaluate the low temperature performance of most SBS modified asphalts. Correlation of 25 ℃ penetration and PG index is higher than correlation of 5 ℃ ductility and PG index, but it needs further study.