Effects of Antioxidant-Intercalated LDHs on Long-Term Thermal Oxidation Aging and Ultraviolet Aging Resistances of SBS-Modified Asphalt

Abstract

This research aimed to enhance the ultraviolet aging and long-term thermal oxidation aging resistances of styrene-butadiene-styrene (SBS)-modified asphalt simultaneously. For this purpose, antioxidant 1222–intercalated ultraviolet (UV) shielding material layered double hydroxides (LDHs) (LDHs-1222) were prepared and added into SBS-modified asphalt as an antiaging agent. The effect of LDHs-1222 on the physical properties, high and low temperature rheology, and chemical composition of SBS-modified asphalt was investigated. Meanwhile, the aging properties of the asphalts after short-term or long-term thermo-oxidative aging and 7-day ultraviolet aging were investigated. The results showed that LDHs-1222 significantly improved the resistance of SBS-modified asphalt to short-term thermo-oxidative, long-term thermo-oxidative, and UV aging while having less impact on the physical and rheological properties than LDHs. Compared with SBS-modified asphalt, the softening point increment, aging indices of viscosity, complex modulus and carbonyl index, and SBS index decrement of the asphalt with LDHs-1222 were significantly reduced, and their growth rates were significantly slowed, indicating that the aging rate and degree of SBS-modified asphalt were reduced by the addition of LDHs-1222. SBS-modified asphalt with 4% LDHs-1222 exhibited superior resistance to long-term thermal oxidation and UV aging compared to asphalt with an equivalent amount of LDHs.