▎ 摘　　要

NOVELTY - Improving toughness of ultra-high performance concrete comprises (i) dispersing graphene oxide in isopropanol solution by ultrasonic to obtain a uniformly dispersed graphene oxide-isopropanol mixture, adding steel fibers into the mixture, stirring continuously until the graphene oxide is completely adsorbed to the surface of the steel fiber, then add micro-nano-scale quartz powder, stirring continuously to make the quartz powder adsorb to the surface of the graphene oxide, separating the steel fiber from the isopropanol solution, and drying the steel fibers to obtain steel fibers layered with quartz powder and graphene oxide. USE - The method is useful for improving toughness of ultra-high performance concrete. ADVANTAGE - The method: utilizes the oxidation graphene and quartz powder to pre-treat the steel fiber, which can increase the roughness of the fiber surface, overcomes the defect that the traditional steel fiber is easy to be pulled out from the ultra-high performance concrete (UHPC) substrate, so as to greatly improve the holding force between the steel fiber and the hardened cement stone, improving the interface bonding strength of the two, and greatly improves the toughness of UHPC; and utilizes the graphene oxide, which has high strength, good flexibility, because the surface tension can be absorbed to the surface of the steel fibers, and because surface grafting oxygen-containing functional group, active site, can absorb a large amount of quartz powder particles. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for ultra-high performance concrete.