Fatigue and Rutting Performance of Airfield SBS-Modified Binders Containing High Modulus and Antirutting Additives

Permanent deformation and fatigue cracking are two main distresses on airfield pavement. To enhance material performances, the researchers introduced three additives in this study: namely, two high modulus agents (HM-1 and HM-2) and an antirutting agent (ARA). Two control binders [Styrene-Butadiene-Styrene (SBS)], a modified binder (PG 76-22), and an unmodified binder (PG 64-22) were blended with additives at 0.3% and 0.6% (by the weight of asphalt mixture). The rutting and fatigue resistances of a total of fourteen binders and five mixtures (AC-20) were evaluated by temperature and frequency sweeps, multiple stress creep recovery (MSCR) tests, and linear amplitude sweep (LAS) tests as well as by the Hamburger Wheel Tracking (HWT) and the four-point bending beam (FBB) fatigue tests for mixtures. From the laboratory investigation, it was found that the additions of additives increased the $|G^{*}|/\sin \delta$ and $R$ value and decreased the $J_{nr}$ value at high performance temperatures. Also, the $|G^{*}|$ master curve showed the stiffness of the binder increased when the additive content rose. The antirutting agent (ARA) had more effects on rutting resistance than HM-1 based on HWT results. The relationship between binder indicators ($J_{nr}$ and $|G^{*}|/\sin \delta$) and mixture creep slope was great. As for fatigue performance, HM-1 modified binders showed higher fatigue lives than ARA modified binders at a high strain level. Furthermore, the fatigue life of mixtures at 500 με had weak correlations with fatigue life and $A_{35}$ predicted by the LAS test at the strain level of 2.5%.