Yubin Sun

Performance Evaluation of SBS Modified Asphalt with Different Anti-aging Additives

The effects of three different types of anti-aging additives (bumetrizole, octabenzone, and tinuvin770) on the physical and rheological properties of styrene butadiene styrene (SBS) modified asphalt were investigated by means of conventional physical properties tests and dynamic shear rheometer (DSR) tests. In order to evaluate the aging properties of different anti-aging additive/SBS modified asphalts, the thin film oven test and ultraviolet (UV) radiation test were performed, and different aging parameters were compared. The results show that the penetration, ductility, and softening point are increased, whereas the viscosity is decreased, with the addition of different anti-aging additives. The DSR analysis indicates that anti-aging additives can enhance the elastic behavior and improve the thermal stability of SBS modified asphalt. Improvement in the thermal-oxidative aging properties of SBS modified asphalt can be achieved with the three different anti-aging additives, but the UV aging properties of anti-aging additive/SBS modified asphalts are dependent on the type of anti-aging additive. Of the three different anti-aging additives, tinuvin770 improves both the thermal- and the photo-oxidative aging resistance of SBS modified asphalt significantly.

Investigation of γ-(2,3-Epoxypropoxy)propyltrimethoxy Silane Surface Modified Layered Double Hydroxides Improving UV Ageing Resistance of Asphalt

γ-(2,3-Epoxypropoxy)propyltrimethoxy silane surface modified layered double hydroxides (KH560-LDHs) were prepared and used to improve the ultraviolet ageing resistance of asphalt. The results of X-ray photoelectron spectrometry (XPS) indicated that KH560 has been successfully grafted onto the surface of LDHs. The agglomeration of LDHs particles notably reduced after KH560 surface modification according to scanning electron microscopy (SEM), which implied that the KH560 surface modification was helpful to promote the dispersibility of LDHs in asphalt. Then, the influence of KH560-LDHs and LDHs on the physical and rheological properties of asphalt before and after UV ageing was thoroughly investigated. The storage stability test showed that the difference in softening point (ΔS) of LDHs modified asphalt decreased from 0.6 °C to 0.2 °C at an LDHs content of 1% after KH560 surface modification, and the tendency became more pronounced with the increase of LDH content, indicating that KH560 surface modification could improve the stability of LDHs in asphalt. After UV ageing, the viscous modulus (G’’) of asphalt significantly reduced, and correspondingly, the elastic modulus (G’) and rutting factor (G*/sin δ) rapidly increased. Moreover, the asphaltene increased and the amount of “bee-like” structures of the asphalt decreased. Compared with LDHs, KH560-LDHs obviously restrained performance deterioration of the asphalt, and helped to relieve the variation of the chemical compositions and morphology of asphalt, which suggested that the improvement of KH560-LDHs on UV ageing resistance of asphalt was superior to LDHs.

The Effect of Zinc Doped Mg-Al LDHs on Ultraviolet Aging Resistance of Asphalt

Effects of zinc doped Mg-Al layered double hydroxides (Zn-Mg-Al LDHs) and Mg-Al LDHs on physical and ultraviolet (UV) aging properties of asphalt were evaluated by conventional physical properties, dynamic rheological characteristics and Fourier transform infrared (FTIR) spectroscopy. The results show that the introduction of LDHs improves the UV aging resistance of asphalt. By comparison, Zn-Mg-Al LDHs are superior to Mg-Al LDHs in improving aging performance of asphalt, which is due to the more outstanding UV shielding of Zn-Mg-Al LDHs in comparison with Mg-Al LDHs, leading to a beneficial effect in improving UV aging performance of asphalt.

Effect of surface organic modified layered double hydroxide on UV ageing resistance of bitumen

ABSTRACT Layered double hydroxide (LDH) was surface organic modified by γ-(2,3-epoxypropoxy) propyltrimethoxysilane (KH560) and applied to improve UV ageing resistance of bitumen. KH560 has been successfully grafted to the surface of LDH according to Fourier Transform Infrared Spectroscopy. Then, the effect of KH560 surface modified LDH (KH560-LDH) and LDH on physical and rheological properties of bitumen were thoroughly investigated. The results showed that KH560-LDH existed more stably in bitumen and KH560-LDH-modified bitumen possessed better high-temperature performance compared with LDH. After UV ageing, the properties of bitumen became worse obviously. Compared with LDH, KH560-LDH exhibited better improvement on UV ageing resistance of bitumen.

Effect of layered double hydroxides on ultraviolet aging resistance of SBS modified bitumen membrane

Layered double hydroxides (LDHs)/styrene-butadiene-styrene (SBS) copolymer modified bitumen was prepared by melt blending. The effect of LDHs on the ultraviolet (UV) aging behavior of SBS modified bitumen was investigated. The changes of chemical structures of modified bitumen before and after UV aging were characterized by Fourier transform infrared spectroscopy (FTIR). The results show that LDHs obviously reduce the variation of softening point and low temperature flexibility of SBS modified bitumen under different UV radiation intensities, which indicates that the UV aging resistance performance of SBS modified bitumen is improved effectively by LDHs. Compared with SBS modified bitumen, the changes of carbonyl, sulfoxide and butadienyl of LDHs/SBS modified bitumen decrease significantly after UV aging according to FTIR analysis, demonstrating that the oxidation and degradation reactions of SBS modified bitumen were restrained effectively by adding LDHs.