# Multifunctional Graphene-Concrete Composites: Performance and Mechanisms
## 1 Introduction
Additionally, such materials facilitate the regulation of indoor temperatures, thereby lowering the energy consumption of air conditioning systems and enhancing overall energy efficiency. [PERSON] et al. utilized hemp concrete, which possesses low thermal conductivity and high specific heat capacity, to minimize energy loss through the building envelope. They employed modeling analysis using ANSYS Fluent software15.0 to investigate the influencing factors on energy storage and loss [18]. Additionally, the impermeability of concrete, being a porous material, can be improved through the incorporation of slag, polymers, and cernasite [19; 20; 21]. [PERSON] et al. utilized alkali-activated slag cementing material (AASCM), characterized by rapid hardening, early strength development, high strength, and a low carbon content, for the repair of damaged concrete [22]. Through tests on water penetration, chloride ion penetration, and microanalysis, it was demonstrated that alkali-activated slag cementing material (AASCM) enhancesthe impermeability of repaired specimens. Graphene possesses high thermal conductivity, a stable lattice structure, excellent heat-transfer capability, and significant strength, making it an effective thermal-conductivity enhancer. Its remarkable photothermal, chemical, and electrical properties have led to its widespread application across various fields [23; 24]. [PERSON] et al. investigated the microstructure, mechanical properties, and durability of concrete enhanced with graphene and graphene-based compounds as additives. Their analysis revealed that these additives significantly improve the mechanical properties and longevity of concrete [25]. [PERSON] et al. reviewed recent advancements in the synthesis and manufacturing of graphene nanocomposites across various energy-storage systems. They also discussed the latest developments in the production and application of energy-storage materials, along with the future prospects and potential challenges associated with energy-storage applications [26]. [PERSON] et al. investigated the performance of conductive grid asphalt concrete by incorporating graphene and carbon fibers as conductive phase materials. The study evaluated key mechanical and durability properties, including high-temperature stability, low-temperature crack resistance, and water stability, through standardized tests such as high-temperature rutting tests, low-temperature bending tests, and immersion Marshall tests. The results demonstrated that the addition of graphene significantly improved the high-temperature stability, low-temperature crack resistance, and water stability of the conductive grid asphalt concrete [27]. [PERSON] et al. developed a porous cement-based photothermal conversion material by depositing a graphene layer as a photothermal conversion coating on the surface of porous cement substrates. The study systematically evaluated the material's photothermal conversion efficiency and water evaporation performance. The results revealed that the graphene-based photothermal conversion layer exhibited remarkable efficiency in both photothermal conversion and water evaporation, demonstrating its potential for solar energy utilization [28]. [PERSON] et al. investigated the impact of graphene and graphene oxide on the hydration kinetics of cementitious systems. Employing advanced analytical techniques, including simulated potential measurements, scanning electron microscopy (SEM), and isothermal calorimetry, the study demonstrated that the highly mobile ions associated with graphene and graphene oxide significantly accelerate the cement hydration process. These findings provide critical insights into the mechanistic role of carbon-based nanomaterials in enhancing the early-age properties of cementitious materials, offering potential applications for optimizing the construction material performance [29]. The novelty of this paper lies in the integration of graphene into concrete as a photothermal material.