3D porous graphene nanosheets as efficient additives for high-performance styrene–butadiene–styrene/crumb rubber blend-modified asphalt

Abstract

Styrene-butadiene-styrene (SBS)/crumb rubber (CR) blend-modified asphalt is a desirable binder for pavement engineering with both environmental and economic benefits. However, the inherent incompatibility of SBS and CR in asphalt is still a critical issue. Herein, 3D porous graphene (3DPG) with high surface area and rich micropores as reinforced additive was investigated in SBS/CR blend-modified asphalt for the first time. The experimental results demonstrate that incorporating 3DPG can effectively improve the compatibility of SBS and CR in asphalt and thus significantly enhance the high and low temperature performance and fatigue resistance of the modified asphalt, compared with that without 3DPG. Theoretical calculations further reveal that the nanopores in graphene can endow graphene with electrophilic property, providing a capability of absorbing nonpolar molecules in asphalt while the non-pore part in graphene can interact with polar molecules by conventional π − π stacking. The two forces within graphene can break the original colloidal structures of asphalt, which is conductive to the homogenous formation of SBS network and swelling of CR in asphalt, significantly promoting the pavement performance of the modified asphalt. This work presents the great potential of 3DPG as new additive to solve the inherent incompatibility of SBS/CR blend-modified asphalt for high-grade pavement engineering.