Effect of Coal-Derived Graphene Oxide on the Mechanical and Microstructural Characteristics of Concrete.

Past studies have offered insights into how graphite-derived graphene oxide (GDGO) can improve the mechanical properties and alter microstructural characteristics of concrete. These advantages can significantly impact the construction industry regarding cost, sustainability, and efficiency. However, the high cost of GDGO can make commercial implementation unattainable. This paper comprehensively investigates coal-derived GO as a cost-saving alternative to commercial GDGO while achieving comparable concrete performance. Different GO proportions were incorporated into concrete mixes through laboratory experiments to determine the effect on mechanical properties and microstructures. In this research, concrete mixes were formulated by replacing a portion of cement with coal-derived GO and adding this GO as an additive to concrete at varying percentages (0.05%, 0.10%, 0.25%, 0.50%, 1%, and 1.5% by weight of cement). The study revealed flexural, split tensile, and compressive strength improvements of 3.3%, 2.3%, and 21.2%, respectively, at a minimal 0.05 wt.% GO replacement. Optimal inclusions of GO as an additive ranging from 0.05 to 0.25 wt.% were identified to exhibit a maximum increase in mechanical properties. More precisely, adding 0.10 weight percent of GO as an additive to concrete showed increases in flexural, split tensile, and compressive strengths of 14.05%, 9.7%, and 34.2%, respectively. Furthermore, detailed analyses, including modulus of elasticity, Poisson's ratio, heat of hydration, and microstructural analysis provided comprehensive insights into the enhanced mechanical performance of GO-incorporated concrete. Additionally, the study revealed a lower Ca/Si ratio in GO concrete, further validating the reinforcing properties of the GO.