Feasibility study of producing inexpensive graphene for use in cement composites

The high cost and the accumulation phenomenon of graphene in the cement matrix are the main obstacles to its use in the concrete industry. In this study, both of the above challenges were solved by producing graphene through the combination of graphite and polycarboxylate ether-based superplasticizer by exfoliation method. In this regard, mechanical properties and permeability, as well as comprehensive microstructural studies, were investigated for the feasibility of using graphene produced based on superplasticizer in cement composites. The SEM and TEM analyses revealed that the multilayer graphene sheets produced with a polycarboxylate ether-based superplasticizer are of high quality and have few defects. According to the results of this research, the sample containing graphene based on the combination of 5 grams per liter of graphite and superplasticizer at the rate of 0.1% of the cement used, the compressive and bending strength was increased by 82.05% and 33.56%, respectively, compared to the control sample at the age of 3 days. On the other hand, the porosity in the graphene-containing mixture is reduced by 50% compared to the control sample. Besides, the results demonstrated that graphene has an effective influence on capillarity absorption due to increased twisting and modification of cement matrix pores. Also, the XRD results showed that using solution containing graphene led to the consumption of C3S and C2S at the age of 3 days and more CH, CSH phases were formed in the cement structure. These results together with TGA and FESEM characterization results showed that the effect of graphene nucleation is more evident at early ages.