Effect of Organic-Montmorillonite on rheological performance of Bio-Asphalt composites with various oxidative aging

Abstract

Several previous studies have demonstrated that bio-asphalt derived from Waste Cooking Oil (WCO) displays superior performance in cracking resistance at low and medium temperature, but inferior in high temperature rutting resistance. This study aims to further improve the rutting resistance of WCO based bio-asphalt by a compound modification with Organized Montmorillonite (OMMT). One neat asphalt binder with penetration grade of 90 is selected in this study. The WCO based bio-oils are firstly mixed with neat binders followed by further modified with the OMMT additives. The frequency sweep, linear amplitude sweep (LAS) and multiple stress creep recovery (MSCR) tests are respectively conducted for evaluation of the linear viscoelastic properties, fatigue and rutting resistance. Experimental results demonstrate again that the fatigue resistances of bio-binders are improved compared to the base asphalt whereas the addition of bio-oil obviously reduces the binder rutting resistance at high temperature. However, the OMMT addition into the bio-asphalt is found to effectively enhance the rutting resistance when increasing the OMMT content without compromising the fatigue performance. Therefore, it can be preliminary concluded that the Bio/OMMT compound modification approach can be utilized to address the rutting potential concern of WCO based bio-binders at high temperature. Furthermore, the Response Surface Methodology (RSM) is employed to model the rheological properties of Bio/OMMT compound modified binder under various modifier weights, in which the damage characteristic and performance index can be effectively estimated.