Henglong Zhang

The Effect of Different Nanomaterials on the Long-term Aging Properties of Bitumen

Effect of expanded vermiculite (EVMt) and nano-zinc oxide on thermal-oxidative (pressurized aging vessel, in situ thermal aging) and ultraviolet (UV) aging was investigated. The results show that organic expanded vermiculite (OEVMt) modified bitumen forms an exfoliated nanostructure. The morphology of bitumen is significantly influenced by two nanomaterials according to atomic force microscopy. The influence of different nanomaterials on long-term aging resistance of bitumen depends on their structures and shielding function to UV radiation. Thermo-oxidative aging resistance of bitumen can be effectively improved with the introduction of OEVMt, while nano-zinc oxide has obvious improvements in UV aging resistance of bitumen.

The Effect of Surface Modifiers on Ultraviolet Aging Properties of Nano-zinc Oxide Modified Bitumen

Nanocomposites based on bitumen and nano-zinc oxide with three surface modifiers, γ-methacryloxypropyl trimethoxy silane (MTS), 3-aminopropyltriethoxysilane (APTS), and γ-(2,3-epoxypropoxy) propytrimethoxysilane (EPTMS), have been prepared by melt blending. The influence of surface modifiers on ultraviolet (UV) aging properties of nano-zinc oxide modified bitumen was evaluated. The results show that MTS, APT, and EPTMS are successfully bound on the surface of nano-zinc oxide. The dispersion stability of nano-zinc oxide in bitumen is improved by three surface modifiers. Compared with MTS and EPTMS, APTS-nano-zinc oxide modified bitumen shows the lowest VAI values and carbonyl index after UV aging, indicating its good UV aging resistance.

The Effect of Surface-modified Nano-titania on the Ultraviolet Aging Properties of Bitumen

The effect of surface modification of nano-titania on ultraviolet (UV) aging properties of bitumen was investigated. The results show that γ-(2,3-epoxypropoxy) propytrimethoxysilane is bound on the surface of nano-titania according to Fourier transform infrared spectroscopy analysis. The dispersion stability of nano-titania in bitumen is improved by surface modification of nano-titania. Viscosity aging index values and carbonyl indexes of the bitumen are decreased by adding nano-titania. After surface modification, the UV aging resistance of nano-titania modified bitumen can be further improved. The result suggests that nano-titania can be effectively used as a modifier to improve the UV aging resistance of bitumen.

Effect of Nano-zinc Oxide on the Morphology and Ultraviolet Aging Properties of Various Bitumens

Effect of nano-zinc oxide (nano-ZnO) on the morphology and ultraviolet (UV) aging properties of two bitumens was investigated by atomic force microscopy, physical properties and Fourier transform infrared spectroscopy before and after UV aging. The results show that the mechanism of nano-ZnO depends on the base bitumen. In one case, nano-ZnO contributes to the homogeneous dispersion of bee-like structures. In the other case, it leads to the separation of asphaltenes from the matrix. Compared with B2, nano-ZnO exhibits a better improvement in UV aging resistance of B1 by showing the lower increased viscosity values, rheological aging index, and carbonyl indexes.

Effect of different rejuvenators on the properties of aged SBS modified asphalt

ABSTRACT The styrene-butadiene-styrene copolymer (SBS)–modified asphalt was aged by pressure aging vessel test. The effect of different content of rejuvenators on the physical and rheological properties of aged SBS-modified asphalt was investigated. The results showed that with the increase of the content, the physical and rheological properties of the aged SBS-modified asphalt are restored more significantly. Three kinds of rejuvenators were used to rejuvenate the properties of aged SBS-modified asphalt. It can be concluded that the improvement of rejuvenator-III on the properties of aged SBS-modified asphalt is the most obvious. The results also indicate that the rheological behavior of the aged SBS-modified asphalt is improved obviously by the rejuvenator.

The Investigation of Microstructures and Situ Thermal Aging Mechanism of Organic Rectorite Modified Bitumen

Organic rectorite (OREC) was prepared by using cetyltrimethyl ammonium bromide as organic modifiers. X-ray diffraction analysis and the dissolving-filtrating procedure were combined to determine the microstructures of OREC modified bitumen. Situ thermal aging mechanism of the binders was characterized by atomic force microscopy. The results show that OREC modified bitumen forms a semi-exfoliated nanostructure. The situ thermal aging resistance of bitumen can be effectively improved with the introduction of OREC, which can prevent the association of the dispersed domains and the single phase trend of bitumen during aging. It indicates that OREC can effectively improve thermal aging resistance of bitumen.

Effect of Rectorite and Its Organic Modification on Properties of Bitumen

Two organic rectorites (ORECs) were prepared by using cetyltrimethyl ammonium bromide (CTAB) and octadecyl dimethyl benzyl ammonium chloride (ODBA) as organic modifiers to modify the rectorites. Rectorite and OREC modified bitumens were prepared by melt blending. Microstructures of the modified bitumens were characterized by X-ray diffraction (XRD). The effect of rectorite (REC) and its organic modification on the physical and aging properties of bitumen was investigated. X-ray diffraction results show that REC and ODBA-REC modified bitumens form the intercalated nanostructure, whereas CTAB-REC modified bitumen forms an exfoliated nanostructure. Compared with RECs, ORECs show the better compatibility with the bitumen as well as the higher improvement in softening point, viscosity, and aging resistance of the bitumen. The CTAB-REC modified bitumen shows lower viscosity aging index values and softening point increment in comparison with the ODBA-REC modified bitumen, indicating its good aging resistance.

Properties of Bitumen Containing Various Amounts of Organic Montmorillonite

AbstractThe effects of various amounts of organic montmorillonite (OMt) on the morphology and physical properties of bitumen before and after ultraviolet (UV) aging were investigated. The microstructures of OMt modified bitumens were characterized by X-ray diffraction (XRD) analysis. The morphology of the binders was analyzed by atomic force microscopy. According to the XRD results, OMt modified bitumens form an intercalated nanostructure. As a result of UV aging, OMt modified bitumens show lower viscosity aging index and softening point increments than unmodified bitumens, which are further decreased by increasing the OMt content, indicating the satisfactory UV aging resistance of OMt modified bitumen. However, the softening point increments and viscosity aging index decrease slowly when OMt content increases above 6% by weight. UV aging significantly influences the morphology of bitumen. The contrast between the matrix and dispersed domains is decreased and a single-phase trend occurs in the bitumen dur...

The Effect of Sodium and Organic Montmorillonites on the Thermal Aging Properties of Bitumen

Effect of sodium and organic montmorillonites on the thermal aging properties of bitumen was investigated by thin-film oven test and pressure-aging vessel test. The microstructures of montmorillonite and the binders were characterized by X-ray diffraction. The results show that the sodium montmorillonite (Na+-Mt) modified bitumen forms a phase-separated structure, while the organic montmorillonite (OMt) modified bitumen forms an intercalated structure. The thermal aging properties of bitumen are improved obviously with the introduction of montmorillonite. Compared with Na+-Mt, the changes of physical properties of bitumen are further decreased by OMt, indicating the good aging resistance of intercalated OMt modified bitumen.

Effect of Nanozinc Oxide and Organic Expanded Vermiculite Compound on Antiaging Properties of SBR Modified Bitumen

AbstractThis work focuses on the effect of nanozinc oxide (nano-ZnO) and organic expanded vermiculite (OEVMT) compound on physical and aging properties of styrene butadiene rubber (SBR) modified bi...