Performance properties of WMA modified binders and asphalt mixtures containing PPA/SBR polymer blends

The performance properties of asphalt binders and mixtures can be enhanced utilizing several modifiers, including; Poly Phosphoric Acid (PPA), Warm Mix Asphalt (WMA) modifiers, and Styrene-Butadiene Rubber (SBR). The current study evaluated the effect of PPA and WMA contents on rheological behavior of SBR modified binders and SMA mixtures. The modified binders were subjected to rotational viscosity, Dynamic Shear Rheometer, and Bending Beam Rheometer, Multiple Stress Creep Recovery (MSCR), and Linear Amplitude Sweep (LAS) tests. The SBR/PPA and SBR/PPA/WMA modified mixtures were subjected to Indirect tensile strength (ITS), dynamic creep, resilient modulus (M-r ), wheel track, and four-point beam fatigue (FPB) tests. To analyze the data, two-factor analysis of variance (ANOVA) was investigated. Based on the results of the MSCR test at both stress levels, modification of base bitumen by SBR, PPA and WMA additives causes an enhance in permanent deformation performance of original bitumen. LAS test results indicated that, utilization of SBR and WMA additives improves the fatigue life of bitumen. Also, by addition of PPA, the fatigue life of SBR modified binders increases. whereas, the fatigue lives are higher than original binders ones. Based on results, utilization of SBR and PPA enhances the M-r , rutting properties, ITS, FE, and fatigue behavior of specimens. By increasing the PPA percentage, the rutting and fatigue behavior enhances. Whereas, it causes a decreases in M-r and ITS of modified mixtures. Among warm additives, sasobit has better effect on enhancing the performance of binders and mixtures.