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

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.

Effect of Biowaste on the High- and Low-Temperature Rheological Properties of Asphalt Binders

The growth of aquaculture has increased the production of oysters. However, the increased oyster shell volume has created serious environmental and recycling problems for the society. In order to study the sustainable utilization of waste oyster shells, asphalt binder of waste oyster shell powder was prepared by using modified asphalt material with waste oyster shells. The microstructure of oyster shell powder was analyzed by scanning electron microscopy experiments. The chemical composition of the asphalt binder was observed by Fourier transform infrared spectroscopy tests. The physical properties of the asphalt binder, including softness, high-temperature performance, and plastic deformation capacity, were initially evaluated through three indicators’ tests on asphalt. A preliminary performance evaluation of the asphalt binder was performed. The high-temperature stability of asphalt binders was evaluated using dynamic shear rheometry. The rutting resistance of the material was evaluated by temperature sweep tests, and the shear deformation resistance of the material was evaluated by frequency sweep tests. Multiple stress creep recovery tests determine the material’s ability to resist permanent deformation. The low-temperature rheological properties were evaluated by bending beam rheology tests. The study found that the waste oyster shell powder is a biomass with a porous irregular petal shape. No new characteristic absorption peaks are formed by mixing with asphalt. And, it can improve the viscosity, thermal stability, and temperature-sensitive properties of the material. It significantly improved the high-temperature rheological performance, rutting coefficient, and recovery elasticity of the material. However, it has little effect on low-temperature rheological performance. This study provides a solid foundation for the effective use of biowaste in engineering materials.