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The paper deals with the modification of concrete and epoxy resin with a 2D carbon material (2DCM) obtained by liquid-phase shear exfoliation of graphite. It was experimentally established that the three-point bending strength of graphene-modified samples (0.05 wt.% of graphene in cement) in 1.5 times greater than that of pristine (unmodified) concrete. The water absorption of concrete modified with the 2DCM was found to decrease by 3 times. A method, differing from the known ones where few-layered graphene is obtained directly in the hardener through shear exfoliation of graphite, was developed for modifying the ED-20 epoxy resin using the 2DCM. It allowed us to increase the Charpy impact strength by 25-30 %. The tensile and bending strength were increased by 10 %. The test results of the restored beams after breaking at three-point bending, as well as on the adhesion of the reinforcing fabric to concrete, revealed a synergistic effect while using the concrete and epoxy resin modified with the 2DCM.

Epoxy resins are oligomers containing epoxy groups and capable of forming cross-linked polymers under the action of hardeners. Epoxy resins are used in the production of adhesives, plastics, glass and carbon plastics, pouring compounds and plastoconcrete. These materials are widely used in construction, mechanical engineering, aircraft and rocket construction, shipbuilding. To improve the performance of epoxy resins, their chemical or physical modification is used. The paper focuses on physical modification of carbon nanomaterials in order to improve the strength characteristics. Methods for modifying epoxy resins with graphite, carbon nanotubes and graphene are analyzed. It is shown that graphene is the most promising material improving the strength characteristics of epoxy resins.

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