Evaluation of fatigue and rutting properties of asphalt binderand mastic modified by synthesized polyurethane

Fatigue and rutting phenomena are major distresses in asphalt pavements. Asphalt mixture properties are highly dependent upon the asphalt binder and the mastic behavior. The purpose of this study was to investigate the behavior of the asphalt binder and the mastic,modified by the synthesized polyurethane, at high and intermediate temperatures. The filler/asphalt binder ratio(by weight) was 1.0. The dynamic shear rheometer(DSR) was used to measure fatigue(G~*sin δ) and rutting(G~*/sin δ) parameters. In this study, the multiple stress creepandrecovery(MSCR) testwasalso utilizedto calculate the ruttingpotential of theasphalt binder and themastic. Parameters of the non-recoverable compliance(Jnr) and the percentage recovery(%) were evaluated at high temperatures. The obtained results indicated that the synthesizedpolyurethaneimproved the ruttingandfatigue properties.Therewasa significant correlation between the asphalt binder and the mastic in terms of the complex modulus(R~2 = 0.9958), rutting(R~2 = 0.9944), and the non-recoverable compliance(R~2 = 0.9707). For the fatigue parameter(R~2 = 0.9852), the complex modulus(R~2 = 0.9855), and the phase angle(R~2 = 0.8262), significant relationships were observed between the asphalt binder and mastic samples at intermediate temperatures. Overall, the chemical reaction between the filler and the asphalt binder could be effective in different behaviors of the mastic and asphalt binder.Therewasa 112%-164%increase in the G~* sin δ parameter formastics,compared to that of the asphalt binder. The complex modulus was 6 times higher by adding the filler content.