Mechanical strength and electrical conductivity of concrete composites enhanced with graphene oxide

Abstract

The development and application of “smart”, multifunctional, and hybrid materials are among the most significant areas of modern materials science. This article presents the results of mechanical testing, microstructural analysis, evaluation of electrophysical properties, and stochastic modeling of the failure of samples made from a concrete composite reinforced with recycled secondary materials in the form of reduced graphene oxide. The aim of this work was to create materials with increased strength and a given electrical conductivity. An overview of research on the creation and modeling of failure processes in hybrid materials is provided. Approaches for assessing stress states are presented, and the use of the concept of the pre-fracture zone and structural scale to describe failure processes in quasi-brittle materials is justified. It has been shown that the high strength and electrical conductivity properties of graphene can significantly enhance the characteristics of a hybrid composite material with a low concentration of modifier. Concrete samples were prepared with graphene oxide mass fractions of 0.2% and 0.5%. Structural and chemical characterizations were conducted via scanning electron microscopy and infrared spectroscopy. Mechanical testing demonstrated that the inclusion of reduced graphene oxide at 0.5% concentration increased strength by 48% and decreased electrical resistance to 550–600 ohms, with conductivity values reverting to baseline upon load removal. These findings suggest that graphene modification significantly enhances the electrical and mechanical performance of concrete composites. Therefore, these hybrid materials hold considerable potential for use in structural health monitoring systems, selfheating elements, grounding electrodes, and for improving the reliability and safety of energy infrastructure and engineering systems, especially those functioning in harsh Arctic and Subarctic environments.