Experimental study on rheological characteristics and performance of high modulus asphalt binder with different modifiers

The fundamental material for production of high-modulus asphalt (HMAC) is high modulus asphalt binder (HMAB), which is normally manufactured from hard-grade asphalt, rock asphalt modification, and polyolefin modification. This paper investigated rheological properties and performance of HMAB as compared to Styrene-Butadiene-Styrene (SBS) modified binder and neat binder using comprehensive laboratory performance tests. Specifically, the performance of HMAB modified with two different high modulus additives, rock asphalt (RA) and polyolefin (PR), were compared. The performance indicators include linear viscoelasticity characterized by temperature sweep and frequency sweep tests, rutting resistance by multiple-stress creep recovery (MSCR) test, and fatigue resistance by linear amplitude sweep (LAS) test. The effects of high-modulus modifier on master curve of dynamic shear modulus of HMAB were found identical. The temperature dependencies of asphalt binder were found to be significantly dependent on the material source of neat binder. However, the rutting resistance of HMAB modified by rock asphalt and polyolefin is better than that of SBS modified binder and neat binder. The polyolefin modified HMAB showed better rutting resistance than rock asphalt modified HMAB; while the comparison results was opposite for fatigue resistance. The simplified viscoelastic continuum damage (S-VECD) theory was employed to interpret the LAS test results for fatigue life prediction of asphalt binder. The SBS binder showed the best fatigue performance followed by HMAB and neat binder.