Influence of Graphene Oxide and Ground Granulated Blast Furnace Slag on Engineering Properties of High-Performance Concretes

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Abstract Concrete structures immersed in sea water suffer severe corrosion, and the application of nanomaterials to concrete presents an innovative approach to enhancing both its physical and mechanical properties. In this paper, the effects of combined admixtures of graphene oxide nanoplatelets (GONPs) and ground granulated blast furnace slag (GGBFS) on concrete were studied, and mechanical and physical tests were performed. It was known that the GGBFS admixture improves the durability of concrete, but in concrete samples containing both GONPs and GGBFS, the compressive strength increased by nearly 43 % and 46 % at 28 and 90 days of curing, respectively, compared with ordinary portland cement (OPC) concretes. The same admixing regime caused an increase in flexural strength of up to 58 % and 59 % during the same time spans. This was accompanied with a significant reduction in chloride permeability, which was appraised by a 64 % drop in electrical conductivity measurements. The GONPs additive, even at the very low concentrations, accelerated the formation of calcium silicate hydrate, thereby enhancing the mechanical and flexural strengths that directly affect the durability and water and chloride absorption. The overall durability and rebar corrosion resistance that were shown through electrochemical tests are consequences of the combined improvements in the physico-mechanical concrete properties. OPC concrete is thus both stronger and significantly more chloride ion resistant with additions of GONPs in the parts per million range and by replacing it with 50 percent by weight GGBFS. The enhanced pozzolanic reactions in concrete help to fill the porosity and significantly contribute to the curtailment mechanism.