基于测力延度试验的SBS改性沥青老化特征评价指标

Evaluation Index of Aging Property of SBS Modified Asphalt Based on Force-Ductility Test

采用不同时程的室内薄膜烘箱试验模拟SBS改性沥青的老化过程,对不同老化时间的SBS改性沥青进行常规试验、动态剪切流变试验及测力延度试验,分析针入度、软化点、车辙因子及测力延度相关指标与SBS改性沥青老化时间的相关性,同时分析这些指标与SBS改性沥青中SBS含量的相关性.试验与分析结果表明:针入度、软化点及车辙因子等指标与SBS改性沥青中SBS含量及老化时间的相关关系具有一致性,无法有效地区分SBS含量和老化时间对SBS改性沥青性能的影响;测力延度试验中的韧性指标与SBS含量正相关,且与SBS改性沥青老化时间负相关,是判别SBS改性沥青老化特征的有效指标.

The conventional test, dynamic shear test and force ductility test were carried out for SBS modified asphalt with different times of aging. The aging processes of SBS modified asphalt were simulated by the thin film oven test for different times. Penetration, softening point, rutting factor and ductility were used as evaluation index to analyze the correlation of the aging degree and SBS content in SBS modified asphalt with these index. The results show that penetration is negatively correlated with SBS content and aging degree of SBS modified asphalt; softening point and rutting factor are positively correlated with SBS content and aging degree of SBS modified asphalt; the toughness index is positively correlated with SBS content while negatively correlated with aging degree of SBS modified asphalt. Only the toughness index can be used as an evaluation index to estimate the aging property of SBS modified asphalt effectively.