[Abstract] The dynamic oscillatory test and multiple stress creep recovery (MSCR) test are designed to evaluate the high temperature properties of asphalt binders and the two test methods may present consistency as well as difference when characterizing asphalt binders. Therefore, these two tests were performed on linear and radial Styrene-Butadiene-Styrene (SBS) modified asphalt at varying polymer contents to investigate the similarities and differences between test methods. The wheel tracking test was used to validate the rutting resistance of SBS modified asphalt mixtures.
It was demonstrated by all the test results that radial SBS offers better modification over linear SBS with respect to rutting resistance. MSCR test and wheel tracking test results indicated that the performance gap between linear and radial SBS modified binders is reducing with the increase of SBS content, while the dynamic oscillatory test failed to provide similar information. The Superpave rutting parameter G*/sin δ increases linearly with the increase of SBS content, while the non-recoverable compliance decreases slowly at high SBS content.
Regression analysis has confirmed that there is a linear relationship between the tangent of phase angle from dynamic oscillatory test and the percent recovery from MSCR test. Pearson correlation analysis indicates that (1-1/(tan δ·sin δ))/G* derived from the dynamic oscillatory test offers advantages over G*/sin δ and Jnr3.2 from MSCR test with respect to the correlation to rutting depth from wheel tracking test.
