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This paper explores the feasibility of using SBS/sulfur/soybean-additive in combination in a hard asphalt binder to produce a composite modified asphalt binder. The modification effects of the additives and the influence of different blending protocols were comprehensively studied through laboratory investigations. The rheology of the asphalt binders was evaluated via viscosity, bitumen grading, master curve, Black diagram, isochronal plot, Han diagram, fatigue, creep stiffness and m-value using a bending beam rheometer (BBR), and Multiple Stress Recovery (MSCR) test using a Dynamic Shear Rheometer (DSR). The modified binder's susceptibility to aging effects and thermal stability were also determined by calculation of the aging index (AI) and degree of separation. The results showed that the additives were able to enhance the overall performance of the hard neat Vacuum Tower Bottoms (VTBs) binder by increasing its resistance to rutting, fatigue cracking, and thermal cracking. It was also found that the additives reduced the aging susceptibility of the VTBs binder without any thermal stability or degradation issues after aging conditions. According to the overall performance of the modified binders, a blending protocol for producing a composite modified binder with optimal performance achieved through a well–developed cross-linked polymer elastic network was recommended. [ABSTRACT FROM AUTHOR]

Previous work with Isosorbide Distillation Bottoms (IDB), and other isosorbide and soybean derived materials as additives in polymer-modified warm mix asphalt (WMA) showed that said materials were shown to behave like antistrips in the Hamburg Wheel Tracking Device (HWTD) test when used a dosage of 0.75% by weight of the binder. Because of this evidence, there is an interest in how specimens produced with newly developed isosorbide and soybean bio-derived chemical additives would affect the compaction and dynamic modulus performance of specimens produced at two compaction temperatures (120°C – WMA and 140°C – hot mix asphalt (HMA)) as compared to a control and commercial additives derived from tall oil. There were no statistical differences observed between the additives and the control due to high variability in results for compaction performance, while for dynamic modulus performance only the additive Epoxidized Benzyl Soyate (EBS) performed significantly different from the control and other additives at both compaction temperatures. Only three of the newly developed additives could be identified as WMA additives: Crude Isosorbide (CI), Reactor Product (RP) and Epoxidized Soybean Oil (ESO) based on the number of gyrations and dynamic modulus performance compared to the control group at both compaction temperatures. [ABSTRACT FROM AUTHOR]

Highlights • Three soybean-derived rejuvenators were added to a neat binder. • The thermal properties of the rejuvenators were studied using DSC and TGA. • The thermal properties of the rejuvenators can be related to the rheological changes in the binder. • The rejuvenators behaved differently even though they were derived from same source. Abstract Rejuvenators are widely used to improve the properties of asphalt binders particularly low temperature and fatigue cracking behavior. Rejuvenators vary significantly in terms of their physical properties and chemical composition. The nature of the interaction between the rejuvenators and the base asphalt binders is very complex and an extensive study into the chemical and thermal properties of the rejuvenators and how they impact the rheological properties of rejuvenated binders is of paramount importance. In this research, a neat PG58-28 binder is rejuvenated with three different materials produced from soybean oil at a dosage of 6% by total weight of binder. The rheological properties of the control and rejuvenated binders are assessed using performance grades showing a drop in both the critical low and high temperature grades with rejuvenation. The oxidative stability of the rejuvenators as well as the rejuvenated binders is studied using thermogravimetric analysis (TGA). The crystallization and melting points of the rejuvenators are observed using differential scanning calorimetry (DSC). DSC is also used to examine the glass transition temperatures of the control and rejuvenated binders. The TGA results showed one of the rejuvenators to be susceptible to oxidation which agreed with the rolling thin film oven (RTFO) mass loss results. The glass transition temperature of the rejuvenated binders decreased denoting improved low temperature cracking properties in line with the performance grade results. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sub-epoxidized soybean oil (SESO) reacts with oxidized asphaltenes. • SESO-grafted asphaltenes restore ductility to low quality and recycled asphalt. • Reactive rejuvenators facilitate reductions in cost, energy, and emissions. Here we report the chemical passivation of agglomerated asphaltenes in low-quality asphalts and reclaimed asphalt pavement via epoxidized vegetable oil derivatives. This facilitates the production of new pavements with 45 wt% recycled content and a 30% reduction in cost, energy, and emissions impact over current best practices. Recycled asphalt pavement and low-quality asphalt both represent materials streams with the potential to drastically reduce the energy and emissions footprint of our transportation infrastructure, provided that their poor performance properties can be ameliorated. We show that epoxidized methyl soyate and sub-epoxidized soybean oil act as chemical rejuvenators that reduce the asphaltene content in binder formulations enabling both low-quality asphalt and recycled asphalt pavement fractions far exceeding common usage. We demonstrate that compared to "fluxes", or inert diluents, these bio-based additives show far superior solvency, rheological characteristics, and resistance to cracking as evidenced by both lab-based binder studies and a full-scale demonstration paving project. [ABSTRACT FROM AUTHOR]

Highlights • AESO can be used as an additive in asphalt modification. • AESO decreases viscosity of the neat asphalt binder. • AESO lowers the mixing and compaction temperatures. • AESO reduces the compaction effort of HMA. • LabAESO at high dosages improves resistance against fatigue and thermal cracking. Abstract This investigation examines the modification effect of using two types of acrylated epoxidized soybean oil (AESO) in asphalt binder at various concentration levels. The effects of AESO on rheological performance of neat asphalt binder were evaluated by employing rotational viscosity (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR) tests. The results indicate that AESO has positive softening effects on decreasing the stiffness of asphalt binder, thereby reduces viscosity and lowers mixing and compaction temperatures. Moreover, laboratory produced AESO (LabAESO) performs superior to commercial available AESO (ComAESO) in terms of low temperature properties and fatigue life at the same concentration level and shows no separation. These findings suggest that a sufficiently high level of LabAESO is necessary in asphalt modification to dramatically affect rheological properties, and therefore enhance the neat asphalt binder’s resistance to fatigue damage at intermediate temperatures and thermal cracking for cold regions pavement applications. Overall, LabAESO shows the potential to be used in asphalt modification with desirable performance improvement, and economic and environmental benefits. [ABSTRACT FROM AUTHOR]

Isosorbide distillation bottoms (IDB) are a co-product from the conversion of sorbitol to isosorbide and have been shown to improve low temperature binder performance when tested in the bending beam rheometer. With the successful inclusion of IDB into asphalt, other bio-chemical streams with similar properties to IDB are of interest. The incorporation of bio-additives that create softening of the binder require an evaluation of rutting resistance. To use bio-based chemical additives as a warm mix asphalt modifier, moisture susceptibility must also be examined. The objective of this paper is to evaluate how IDB and several new bio-derived material additives influence the rutting and stripping resistance in WMA binders and mixtures. Rutting resistance of short term age binder is evaluated using the multiple stress creep recovery (MSCR) test and hot mix asphalt (HMA) and WMA evaluation will employ the Hamburg Wheel-Tracking Device (HWTD) test. Reduced mixing and compaction temperatures were achieved with all bio-additives. MSCR and HWTD results using the bio-additives with non-polymer modified binder show no improvements but when with a polymer modified (PM) binder, all additives show statistical improvements in resistance to rutting and stripping compared to a PM control. [ABSTRACT FROM AUTHOR]

• Asphalt binder was modified with sub-epoxidized and poly (acrylated epoxidized) soybean oils. • The undesired properties of recycled asphalt were mitigated with soybean oil-derived modifiers. • The soybean oil-derived modifiers significantly improved the low temperature cracking resistance. • The bio-based polymer significantly improved the high temperature performance. • The bio-based modifiers can have a huge positive impact on the sustainability of pavements. Soybean oil-derived modifiers were used for the improvement of properties of asphalt materials prepared for a pavement demonstration project. The rheological properties of base, biomodified and extracted binders were measured/compared using rheometers. The binder modification resulted in a decrease of 1.2 °C and 2.3 °C in, respectively, the high-and low-temperature grades of base binder, and when the effect of RAP binder was considered, the continuous performance grade (PG) became almost identical with that of base/control binder. Due to the biomodification and the presence of RAP, the binder's elastic recovery (R) increased by 8.0% and its non-recoverable creep compliance (J nr) decreased by 0.13 kPa−1. The tests conducted to evaluate the mechanical performance of the mixtures proved the efficacy of the bio-modifiers used in reversing the undesired effects of reclaimed asphalt pavement (RAP) and improving the performance of asphalt pavements at different temperatures. For instance, the Hamburg wheel tracking (HWT) test results revealed that the presence of bio-modifiers resulted in the increase of stripping inflection point (SIP) by 3619 passes. The disk-shaped compact tension (DCT) test proved the effectiveness of the bio-modifiers used, as these modifiers increased the fracture energy by 113 J/m2. The master curves constructed for the asphalt binders and mixtures indicated an increased stiffness/elasticity at intermediate and high temperatures. [ABSTRACT FROM AUTHOR]