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High temperature and oxidation are two of the most critical factors that cause epoxy asphalt aging. This paper aims to clarify the variation of mechanical performance and structure of effect of cold-mixed epoxy asphalt (CEA) after thermal-oxidative (TO) aging. The mechanical properties of CEA were studied by tensile tests and dynamic mechanical analysis. The microstructure of CEA was studied by Fourier transform infrared spectrum, X-ray photoelectron spectroscopy, SEM, and fluorescence microscopy. The results indicated that the tensile strength of CEA increased to 5.16 MPa, the elongation at break decreased to 50.3%, and the T g decreased significantly after TO aging. TO aging made the epoxy resin in CEA post-cure, oxidate, degrade and the cross-linked network break. Furthermore, the asphalt particles in CEA agglomerated and oxidized. [Display omitted] • ER underwent a post-curing reaction and degradation. • Asphalt underwent volatilization of the light components and an oxidation reaction. • Thermal-oxidative aging destroyed the original phase structure of the CEA. [ABSTRACT FROM AUTHOR]

• Epoxidized soybean oil (ESO) is introduced to prepare ESO modified cold-mixed epoxy asphalt (CEA-ESO) • Increasing ESO content will increase the compatibility of epoxy resin and asphalt. • Increasing ESO content will increase the elongation at break of cured CEA-ESO. Cold-mixed epoxy asphalt (CEA) has been used for paving steel bridges and high-grade roads because of its properties superiority and environmental protection. In order to obtain CEA with excellent performance, it is a significant mean to improve the compatibility between asphalt and epoxy resin (ER) by introducing epoxidized soybean oil (ESO). The viscosity and glass transition temperature (T g) decrease, and the asphalt dispersed more uniformly in the ER with increasing ESO concentration. Based on the dynamic mechanical analysis, the CEA-ESO30 shows only one T g and excellent compatibility between asphalt and ER. The elongation at break and storage modulus of CEA-ESO was higher than CEA, indicating that the flexible ESO molecular chain in the curing networks might improve the stiffness of CEA-ESO. The FTIR spectra exhibited that the ESO reacted with the curing agent to form 3D networks with ER, which may result in good compatibility between asphalt and ER. [ABSTRACT FROM AUTHOR]

Biobased cold-mix epoxy asphalt (BCEA) was prepared by adopting biodiesel and epoxy soybean oil as asphalt solvent and compatibilizer. The strength and toughness attenuation laws under freeze–thaw (FT) cycles of BCEA were studied through tensile tests, flexural tests, and dynamic mechanical analysis. The attenuation mechanism was explored through scanning electron microscopy, Fourier transform infrared spectroscopy and water absorption tests. The results showed that the first FT cycle significantly weakened the strength and toughness of BCEA. After the third cycle, the attenuation rate of storage modulus, loss tangent, and glass transition temperature of BCEA declined. The attenuation mechanism of BCEA is as follows: (1) post-curing and destruction of the cross-linking network, (2) agglomeration and aging of asphalt, and (3) diffusion and reaction of water. This research provided a theoretical basis for the application of BCEA. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biodiesel is recommended to be preferentially adopted as an asphalt solvent. • Asphalt solvents with high boiling points and moderate solubility are recommended. • Asphalt solvents should ensure CEA form a "sea-island" network. • Most asphalt solvents were preserved in the cross-linked network. Cold-mixed epoxy asphalt (CEA) is mixed and cured at room temperature, requiring dissolving asphalt before preparation. It is essential to choose suitable asphalt solvents to prepare CEA with desirable performances. This paper prepared CEAs with five kinds of asphalt solvents, including diesel, biodiesel, 1,2-dichloropropane, trichloroethylene, and solvent naphtha. The rheological properties of the CEA were studied by Brookfield viscometry and bending beam rheometry, then tensile tests and dynamic mechanical analysis were performed to study the mechanical properties. The morphology of the tensile fracture profiles of CEA was observed through scanning electron microscopy. Recommendations for selecting asphalt solvents are as follows: (1) the solubility of the solvent should ensure the formation of sea-island structure in CEA; (2) the solvent should have a high boiling point and moderate solubility to ensure CEA desirable antiaging ability. As a result, biodiesel is recommended and preferentially adopted. According to the ion chromatography, the volatilization of solvents mainly occurred within 48 h during CEA curing, and nearly 60 % of solvents were "sealed" in the CEA, participating in the formation of the cross-linking network. [ABSTRACT FROM AUTHOR]