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The blending degree between virgin asphalt and aged asphalt has a significant effect on road performance of reclaimed asphalt mixture. This study presented an innovative examination of blending behavior between virgin asphalt and aged asphalt incorporating a new bio-based warm-mix rejuvenator (BWR) by utilizing Atomic Force Microscopy (AFM). Through analyzing the variation of several micro-morphology parameters between virgin asphalt and aged asphalt (or recycled asphalt) after blending, an index of regenerative blending degree (RBD) was proposed to quantitatively evaluate their blending behavior, and the effect of various blending temperatures and durations on regenerative blending degree was investigated. The results show that the regenerative blending degree between virgin asphalt and aged asphalt was higher than that between virgin asphalt and recycled asphalt under the same blending condition. A clear linear correlation was observed between the regenerative blending degree calculated by 3D micro-morphology parameters and the dosage of bio-based warm-mix rejuvenator in recycled asphalt, with a correlation coefficient of 0.98. With the increase in blending duration, the regenerative blending degree between virgin asphalt and recycled asphalt increased first and then decreased, but continued to improve with the increase in blending temperature, which indicates that a higher blending temperature and prolonging the blending duration properly have a positive effect on the blending processing between virgin asphalt and recycled asphalt. Compared with the regenerative blending degree calculated by 2D micro-morphology parameters, the regenerative blending degree calculated by 3D micro-morphology parameters is more reasonable to quantify the blending behavior between virgin asphalt and recycled asphalt. [ABSTRACT FROM AUTHOR]

The use of warm-mix recycling technology can reduce the mixing temperature and the secondary aging of binders in reclaimed asphalt pavement (RAP), which is one of the effective ways to recycle high-content RAP. In this study, the penetration, softening point, ductility, and viscosity were used to characterize the conventional physical properties of aged asphalt after regenerating, while a dynamic shear rheometer (DSR), force ductility tester (FDT), and atomic force microscope (AFM) were used to evaluate the rheological performance and micro-morphology of aged asphalt incorporating a new bio-based warm-mix rejuvenator (BWR) and a commercial warm-mix rejuvenator (ZJ-WR). The regeneration mechanism of warm-mix rejuvenators on aged asphalt was analyzed by Fourier transform infrared spectroscopy (FTIR). The results show that the new bio-based warm-mix rejuvenator can restore the conventional physical properties, low-temperature performance, and micro-morphology of aged asphalt with an appropriate dosage, but it has a negative effect on high-temperature performance. In comparison with 2D area parameters, 3D roughness parameters were more accurate in evaluating the variation in micro-morphology of aged asphalt after regeneration. The FTIR analysis results indicate that both the new bio-based warm-mix rejuvenator and the commercial warm-mix rejuvenator regenerate aged asphalt by physical action, and AS=O and AC-H values are more reasonable than the AC=O value for the restoration evaluation of aged asphalt. And the new bio-based warm-mix rejuvenator has a better regeneration effect on the performance and micro-morphology of aged asphalt than the commercial warm-mix rejuvenator. [ABSTRACT FROM AUTHOR]

The aim of this article is to explore the dynamic compaction characteristics of stone mastic asphalt (SMA) and the friction–lubrication effect of internal particles during the superpave gyratory compaction (SGC) process. Firstly, a calculated method for the compaction degree of an asphalt mixture in the gyratory compaction process was defined based on the multiphase granular volume method. Secondly, the gyratory compaction curves of asphalt mixtures were taken based on this calculation method of compaction degree. The dynamic change law of each compaction index (compaction, percentage of air voids, compaction energy index, etc.) during the compaction process was analysed. Finally, the effects of different initial compaction temperatures and different asphalt content on the friction–lubrication effect and compaction characteristics of asphalt mixtures were studied. Research shows that it is reasonable to define the compaction degree by the ratio of the apparent density of the asphalt mixture to the maximum theoretical density of the asphalt mixture during gyratory compaction. The dynamic prediction equations of the compaction degree K and the compaction energy index CEI with the amount of compaction were established, and could effectively predict the compaction degree, percentage of air voids and compaction energy index CEI. The compaction process of the asphalt mixture needed to go through three phases, including periods of rapid growth, slow growth, and stabilisation, and the compaction degree increased by about 10%, 5%, and 1%, in that order, finally tending towards a stable value. The effect of the initial compaction temperature on the forming compaction degree of the asphalt mixture is significant; therefore, it should be controlled strictly in the compaction construction of asphalt mixtures. When the initial compaction temperature of SMA-13 is about 170 °C, the compaction effect is optimal, and the effect of the increase in the amount of compaction at a later stage on the increase in the compaction degree of the asphalt mixture is very low. With the optimal asphalt content, the friction–lubrication effect between the asphalt and aggregate particles is optimal, because it can effectively form an asphalt film, reducing the frictional resistance of the particles moving each other during the compaction process, and the voids will be embedded and filled with each other, finally producing the best compaction result. [ABSTRACT FROM AUTHOR]

The cold recycled mixture has insufficient resistance to cracking, and the process of fracture is incompletely understood. This study used digital image correlation (DIC) technology and a semi-circular bending test to investigate the anti-crack performances and fracture propagation of basalt fiber-reinforced cold recycled mixture (BFCRM). The load-displacement, full-field strain, full-field displacement, displacement rate and crack propagation map were obtained to evaluate the BFCRM's anti-crack performances. The control cold recycled mixture without fibers was also prepared for comparison. Meanwhile, the fracture process zone (FPZ) during loading were compared and quantitatively assessed by digital image correlation analyses, and the fiber distribution and microscopic features at fracture surface was observed by scanning electron microscopy. The results show that the formation of microcracks of BFCRM takes more time than that of the control group without fiber. Based on DIC observations, the basalt fibers maintain strong anti-crack performance in cold-recycled mixtures and reduce fracture damage. The fracture surface morphology also revealed that basalt fiber exhibited adsorption, bridging, anchoring, stability, and strengthening effects at micro/nano scale, which further improved anti-crack performance e and hindered crack development of cold recycled asphalt mixtures. [ABSTRACT FROM AUTHOR]

Human beings have consumed soybean as an excellent food source for thousand years due to its rich protein, fatty acids, minerals, and fibers. However, soybeans were recognized as one of the big eight allergens resulting in allergic symptoms and even could lead to death. With the increasing demand for soybean products, the challenges caused by soybean allergy need to be solved urgently. This review detailly described the pathogenesis and clinical characteristics of soybean allergy, and also the advantages and disadvantages of four different diagnostic methods were summarized. The major soybean allergens and their structures were summarized. Three types of soybean allergy including Type I, III, and IV, which could trigger allergic reactions were reported in this review. Summary in four different diagnostic methods showed that double-blind, placebo-controlled food challenge is recognized as a gold standard for diagnosing soybean allergy. Three types of processing techniques in reducing soybean allergy were discussed, and the results concluded that some novel food processing techniques such as ultrasound, cold-plasma treatment, showed potential application in the reduction of soybean allergenicity. Further, some suggestions regarding the management and treatment of food allergies were addressed in this review. [ABSTRACT FROM AUTHOR]