Rheological and anti-aging performance of SBS modified asphalt binders with different multi-dimensional nanomaterials

Multi-dimensional nanomaterials composed of layered silicates and inorganic nanoparticles are promising anti-aging agents for styrene-butadiene-styrene triblock copolymer modified asphalt binder (SBSMA) aging. However, different combinations of nanomaterials may exhibit different effect on SBSMA. Thus, the objective of this paper was to determine an optimal combination among multi-dimensional nanomaterials composed of 1%organic expanded vermiculite (OEVMT) + 2%nano-silica (SiO2), 2%nano-titanium (TiO2), 2%nano-zinc oxide (ZnO). Further, more appropriate and pavement performance-related methods, such as multiple stress creep recovery (MSCR), linear amplitude sweep (LAS), DSR function (DSRFn) value and shear stress relaxation (SSR) test, were adopted to evaluate effect of multi-dimensional nanomaterials on rheological performance of SBSMA. The results showed that multi-dimensional nanomaterials can improve rutting resistance of SBSMA by increasing its elastic recovery while decreasing viscous flow. The results of DSRFn value and residual stress were nearly consistent, all showing that improvement of cracking resistance of SBSMA was dependent on different combinations of nanomaterials. Except 1%OEVMT + 2%SiO2, other two multi-dimensional nanomaterials obviously improved cracking resistance of SBSMA. In addition, fatigue life of SBSMA was decreased by addition of multi-dimensional nanomaterials, especially for 1%OEVMT + 2%ZnO. Aging resistance of SBSMA was improved by multi-dimensional nanomaterials, especially for 1%OEVMT + 2%TiO2. Among multi-dimensional nanomaterials investigated, 1%OEVMT + 2%TiO2 is recommended for SBSMA after considering both rheological and anti-aging assessments.