This study systematically examined the effects of functional groups (-O, -OH, and -COOH), temperature (200 K-500 K), and defects (single vacancies, double vacancies, and topological defects) on the interfacial structure and mechanical properties of graphene (Gr)/graphene oxide (GO) composites with hydrated calcium silicate (C-S-H). Experiments show that adding Gr and GO significantly increases the compressive and flexural strength of the composite, with GO exhibiting a stronger strengthening effect. Simulation results indicate that oxygen-containing functional groups are key to enhancing interfacial bonding, with the performance improvement attributed to the coordination and hydrogen bonding interactions between polar functional groups and Ca 2+ .Temperature strongly influences material properties. When the temperature rises from 200K to 500K, the peak values of the radial distribution functions for Ca-Ow and Ca-Oc decrease significantly. At the same time, the rate of carbon atom migration increases sharply, leading to a decline in the mechanical properties of the composite. However, the presence of hydroxyl and carboxyl groups can effectively reduce this high-temperature degradation. Defects cause minor fluctuations in the peak values of the radial distribution functions for Ca-Ow and Ca-Oc. Under tensile and compressive loads, defects lead to small changes in mechanical properties, with some composites showing slight improvements. Overall, defects have a much weaker impact on the interfacial structure and mechanical properties compared to functional groups and temperature effects. This research clarifies the key mechanisms underlying the effects of functional group modification, temperature regulation, and defects, offering essential theoretical insights to improve the mechanical properties and high-temperature stability of cement-based composites.
He et al. (Mon,) studied this question.