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Volatile organic compound (VOC) emissions are becoming an increasingly significant issue because of the increasing demand for bitumen in road engineering. This study attempted to develop a type of fume-suppressed bitumen with good comprehensive performance. Initially, 1, 2, and 3% organic montmorillonite and 2, 3, and 4% waxy warm-mix agents were utilised to modify bitumen. Subsequently, the fume suppression and physical and construction performances of the modified bitumen were evaluated, and the modified bitumen with the best comprehensive performance was determined. On this basis, constant- and variable-temperature heating modes were designed to verify the fuel suppression performance of the modified bitumen thoroughly. Finally, the modification mechanism of modified bitumen was investigated via atomic force microscopy. The results indicate that the modifier had the greatest impact on the ductility of the modified bitumen in terms of its physical performance. Although waxy warm mixed agents increase VOC emissions, organic montmorillonite can inhibit this effect. The modified bitumen, composed of 2% organic montmorillonite and 2% waxy warm mix agent, has the best comprehensive performance, with a 40.6% emission reduction rate under constant temperature heating mode and 46.4–28% range from 200 ℃ to 120 ℃ under another mode. The waxy warm mix agents and organic montmorillonite-modified bitumen developed into continuous and dispersed phase systems, respectively, leading to variations in the modified bitumen's physical performance and VOC emission capacity. In contrast, the composite-modified bitumen exhibited a two-phase structure with the surface morphology of an 'egg tray'. This unique structure enhances the heating surface area and facilitates heat conduction, improving the bitumen performance during construction. [Display omitted] • Consideration was given to the VOC emission reduction effect caused by the decrease in viscosity of bitumen. • The efficacy of fume suppression asphalt was verified in two heating modes. • A fume suppression asphalt with commendable comprehensive performance was designed. [ABSTRACT FROM AUTHOR]

This paper provides an overview of rubber bitumen (RB) modification mechanisms, factors affecting storage stability, and characterization methods. The focus is on summarizing the methods to improve the storage stability of RB. Results indicate that the modification of RB primarily involves swelling and degradation. The settling velocity of crumb rubber (CR) is influenced by the particle size, density, and bitumen viscosity. To evaluate the storage stability of modified bitumen, widely applicable and preferred methods include softening point and rheological property tests. The storage stability of RB can be improved by increasing the swelling rate of CR, promoting crosslinking between CR and bitumen, and reducing CR agglomeration. Commonly used improvement methods include CR selection, the Terminal Blend (TB) curing process, adding modifiers, solubilization blending, the screw extrusion process (SEP), chemical reagent activation, and physical energy activation. The TB curing and SEP are more suitable for engineering-scale applications and yield improved results. However, high production temperatures may compromise the mechanical properties of CR, leading to drawbacks such as high energy consumption and environmental pollution, a problem requiring further exploration. Utilizing bitumen analogs rich in aromatic fractions as solubilizers for CR pretreatment has emerged as an effective option, offering advantages such as simplicity, resource conservation, and favorable improvements. Future research should focus on a deeper investigation of these processes. [Display omitted] • Methods to improve the compatibility of crumb rubber with bitumen are summarized. • Different characterization methods for storage stability are evaluated. • Reducing the crosslink density of rubber improves rubber bitumen storage stability. • Solubilization blending can be considered a sustainable and capable approach. [ABSTRACT FROM AUTHOR]

Developments in the field of nondestructive testing (NDT) for road surfaces have gained substantial momentum owing to its advantages of noninvasiveness, and intelligent. This study considers the role of NDT in highway management, maintenance, and operation. Within this context, four NDT methodologies are reviewed, including ground-penetrating radar, laser, infrared thermal imaging, and ultrasonic technologies, in the context of their applications in asphalt pavement evaluation. The principles underlying the functionality of these techniques, coupled with their disease identification capabilities and relevant indices, were elucidated. Moreover, a comprehensive analysis of the factors influencing the precision of NDT is conducted. This review covers the distinct attributes and challenges of applying NDT technologies to asphalt pavements. It also extrapolates the development trajectory in this field by considering future directions and opportunities. The insights gained from this study are expected to galvanize the continues progress and widespread implementation of NDT technologies in asphalt pavement assessment. [ABSTRACT FROM AUTHOR]