This study aimed to reveal the influence of 3D porous graphene on the cementitious composites from multiple scales. At the macro level, the 3D porous graphene could greatly improve the strength, elastic modulus, and crack resistance of the cementitious composite. At the micro level, the nanoindentation test indicated that the thickness of the interfacial transition zone (ITZ) could be reduced by adding 3D porous graphene, and the microcracks and pores could be lowered as well, which led to mechanical enhancement. Besides, statistical nanoindentation technique (SNT), X-ray diffraction (XRD), isothermal calorimetry, energy dispersive spectroscopy (EDS), and scanning electron microscope (SEM) evidenced that the 3D porous graphene could promote cement hydration and strengthen the elastic modulus and hardness of hydration products. Embedded in the hydration products, the 3D porous graphene could fill the cracks and pores and anchor the cement matrix at the micro-scale, which exhibited the reason for the positive effect caused by the 3D porous graphene at the macro-scale.

本研究旨在从多个尺度揭示3D多孔石墨烯对水泥基复合材料的影响。在宏观层面上，3D多孔石墨烯可以极大地提高水泥基复合材料的强度、弹性模量和抗裂性能。在微观层面，纳米压痕测试表明，通过添加3D多孔石墨烯可以减少界面过渡区（ITZ）的厚度，并且可以减少微裂纹和孔隙，从而增强机械性能。此外，统计纳米压痕技术（SNT）、X射线衍射（XRD）、等温量热法、能量色散谱（EDS）和扫描电子显微镜（SEM）证明3D多孔石墨烯可以促进水泥水化并增强弹性模量和强度。水化产物的硬度。嵌入水化产物中的3D多孔石墨烯可以填充裂缝和孔隙，并在微观尺度上锚定水泥基体，这展示了3D多孔石墨烯在宏观尺度上产生积极作用的原因。