Effect of SBS Modifier Dosage on the Properties of SBS Modified Asphalt and Its FTIR Characterization

To study the effect of SBS content on the elastic-plastic properties and durability of asphalt, the change in the spatial interaction network of SBS modified asphalt was explored. Modified asphalt with SBS dosages of 2.5%, 3.0%, and 4.0% were prepared and the elastic-plastic properties were tested. The changes were investigated through the FTIR test. The findings showed that by changing SBS content, the softening point, penetration index, ductility, and viscosity-toughness did not exhibit an obvious trend, indicating these indexes are not sensitive to SBS content. After the short-term aging, all the indexes showed a continuous trend, indicating that asphalt after short-term aging is more suitable to evaluate performance variance. The addition of SBS introduced new functional groups into the matrix. However, the increase of SBS content can only be seen in functional groups, but does not change the spatial network.