Effect of Graphene Nanosheets on the Abrasion Resistance of Concrete after Different Carbonation Times

Concrete in hydraulic structures is not only abraded by water flow but also corroded by carbonation. It is designed to investigate the enhancement effect and mechanism of graphene nanosheets on the abrasion resistance for the concrete of actual projects. In this paper, the abrasion test of graphene concrete (GC) under different accelerated carbonation times was performed using the underwater steel ball method and compared with control group concrete [crumb rubber concrete (CRC), basalt fiber concrete (BFC), and ordinary concrete (OC)]. Further, microscopic tests were implemented to elucidate the modification mechanism of graphene nanosheets. It was shown that the addition of graphene nanosheets delayed the adverse effects of carbonation on concrete. Adding nanosheets to concrete could significantly improve abrasion resistance. Based on the energy theory, an abrasion energy consumption coefficient was introduced to evaluate concrete abrasion resistance. Without carbonation, the abrasion energy consumption coefficients of GC were 169%, 116%, 103% of OC, BFC, and CRC, respectively. Further, GC's energy consumption coefficient was 377%, 328%, and 196% of OC, BFC, and CRC after 28 days of carbonation. SEM and MIP results showed that the incorporation of graphene nanosheets increased the cement reaction sites, promoted the hydration process, and optimized the microstructure. These findings imply that graphene nanosheets have promising applications in improving the abrasion resistance of hydraulic concrete in carbonation environment.