Effect of ultraviolet aging on rheological properties of organic intercalated layered double hydroxides modified asphalt

The effect of ultraviolet (UV) aging on rheological properties of organic intercalated layered double hydroxides (OLDHs) modified asphalt was investigated by rotational viscosity and dynamic rheological properties. Experimental results indicate that the temperature susceptibility reflected by rotational viscosity and loss tangent of asphalt is decreased due to OLDHs, but the hardening caused by UV aging results in apparent decrease in temperature susceptibility of pristine asphalt, while the temperature susceptibility of OLDHs modified asphalt (OLMA) shows comparatively small decrement, exhibiting better UV aging resistance. Results of dynamic rheological properties show that the addition of OLDHs and LDHs increases the elastic component and rutting factor of asphalt binder at medium and high temperature, leading to a promotion of high temperature performance grade of asphalt. Owing to UV aging, the asphalt binder get stiffer and more brittle, which leads to more elastic behavior. However, the aging of OLMA are weakened for the smaller variations of rheological parameters as compared with pristine asphalt, which indicates excellent UV aging resistance of OLMA due to the introduction of OLDHs. Furthermore, OLDHs exhibit more effective modification than LDHs, which is due to the organic intercalation of LDHs that can improve the compatibility between LDHs and asphalt.