Chemo-Rheological Characterization of the Effect of Iran Rock Asphalt on the Performance of Waste Bio-Oil Modified Asphalts

Abstract

This study aims to investigate the effect of Iran rock asphalt (IRA) on the rheological performance of waste bio-oil modified asphalt (WBMA). Three kinds of WBMA with bio-oil origins including soybean oil residue, castor oil residue, and waste cooking oil residue were blended with different dosages of IRA. The high-temperature performance of the three blended asphalt binders was evaluated using the temperature sweep test and multiple stress creep recovery (MSCR) test. The effect of IRA on the fatigue performance and low-temperature cracking resistance of the three WBMAs was evaluated using the linear amplitude sweep (LAS) test and the bending beam rheometer (BBR) test. A gel permeation chromatography (GPC) test was conducted to further understand the contribution of IRA to the overall rheological performance of different WBMAs. Results indicated that the high-temperature performance of the three WBMAs was enhanced significantly with the increase of IRA content. The predicted fatigue life from the LAS test showed that the incorporation of IRA extended the fatigue life of the three WBMAs at a lower strain level, while this effect was not profound at a higher strain level. Results from BBR test showed that IRA may increase the risk of low-temperature cracking and that the dosage of IRA should be limited to fulfill the requirements of the low-temperature performance. The GPC analysis revealed that the enhanced high-temperature performance and reduced low-temperature cracking resistance of WBMAs modified with IRA was mainly a result of the increased asphaltene concentration.