A laboratory study was conducted to determine the optimum dosage of a bio-based rejuvenator, epoxidised methyl soyate (EMS), needed to obtain a mix design containing 30% unfractionated recycled asphalt pavement (RAP) using a neat asphalt binder with performance grade (PG) 58-28S, rated for standard traffic to meet performance criteria for a PG 58-28S. Based on running a comprehensive rheological characterisation using Superpave binder criteria, 3% EMS by weight of the neat binder was needed to obtain a PG 58-28S at proportions of (75.5% neat binder w/ 3% EMS, and 24.5% RAP extracted binder). The 3% EMS is equivalent to 0.126% by weight of the total mix. Through lab verification, the mix design with 0.126% EMS was shown to meet performance criteria for moisture susceptibility/rutting and low temperature cracking. Field produced mix with 0.126% EMS by weight of total mix was also shown to pass the performance criteria as well for the aforementioned properties. However, the field produced control mix with 20% RAP was not shown to pass criteria for low temperature at −18°C, and thus the field produced control mix became rated as a PG 64-22S. In addition, field density was checked for both the control mix and EMS RAP mix, where both sections had pay bonuses of 3.1% and 4%, respectively.

Weigh-in-motion (WIM) systems are essential for efficient transportation and monitoring parameters such as vehicle number, speed, and weight to ensure regulatory compliance and enhance road safety. Recently, WIM measurements using the Glass Fiber Reinforced Polymer Fiber Bragg Grating (GFRP-FBG) sensors have shown robustness and effectiveness. However, the accuracy of weight evaluation using the WIM systems based on GFRP-FBG sensors can be significantly influenced by the vehicle-wandering effect, which introduces uncertainties in wheel position determination and weight calculations. This paper assessed the impact of vehicle wandering on the accuracy of a WIM measurement system based on GFRP-FBG sensors by utilizing a new hybrid sensor-camera system that integrates roadside cameras and in-pavement GFRP-FBG sensors. The detailed methodology and framework of the developed hybrid system are introduced, followed by field testing on Highway I-94 in the United States. The field testing results indicate that by using the hybrid system, the wheel load detection accuracy of the WIM system based on GFRP-FBG sensors can be controlled to be a Type I or Type III WIM according to the ASTM 1318E-09 standard, with an average accuracy ranging from 87.83% to 94.65%. At the same time, when the wander distance is less than or equal to 9 cm, the developed WIM system proves to be very cost-effective as it only comprises two GFRP-FBG sensors, one temperature FBG sensor, and one camera. These findings indicate the practical potential to enhance the accuracy of WIM systems based on GFRP-FBG sensors designed for highways for low-coast, reliable, and accurate measurements by addressing vehicle wandering effects.

Biorefineries are increasing in number and size and include products based on food, energy, and chemicals. Depending on size and targeted products, biorefineries produce distillation bottoms with surfactant characteristics in sufficient quantities that can be used as a warm-mix asphalt (WMA) technology. Isosorbide distillation bottoms (IDB), having amphiphilic properties much like a classical ionic surfactant, are derived as coproducts of bio-based chemical production and show potential for reducing mixing and compaction temperatures as well as having low-temperature performance grade (PG) benefits. The objective of this paper is to evaluate the performance and potential of IDB as an asphalt additive through asphalt binder testing and mixture testing. Binder gradations were conducted for multiple binders at several dosage rates to verify compatibility with various petroleum crude sources and determine the optimum dosage level. Testing indicates promising results and shows an optimal dosage rate at...