Graphene oxide (GO) has attracted significant attention as a nano-reinforcement for cement-based materials, owing to its exceptional mechanical properties and abundant surface functional groups. However, the precise mechanisms governing its effects in cement composites remain inadequately understood due to inconsistencies and gaps in the existing literature. This review conducts a comprehensive analysis of the dispersion and reinforcement effects of GO in cement materials, focusing on three key areas: (1) challenges associated with achieving uniform dispersion of GO in the high-pH environment of cement slurries and potential strategies to address them; (2) the influence of GO on the macroscopic properties of cementitious composites, including workability, load-bearing capacity, flexural strength, fracture resistance, and durability; and (3) the reinforcement mechanisms of GO, encompassing its role in hydration kinetics, alterations to the calcium-silicate-hydrate (C-S-H) structure, and bonding interactions at the cement matrix interface. Furthermore, recent advancements in optimizing the dispersion and reinforcement effects of GO, such as surface modification techniques, are explored, emphasizing its potential for multifunctional and intelligent applications. This review aims to provide engineering professionals with the latest insights into the application of graphene oxide as a nano-reinforcement in cement-based composites, while offering valuable guidance and direction for future research in this field.

This work aims to investigate the damage in ultrahigh‐performance concrete (UHPC) caused by freezing‐thawing action. Freezing‐thawing tests were carried out on UHPCs with and without steel fibers. Mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and X‐ray computed tomography (X‐ray CT) were applied to detect the microstructure of the UHPC matrix before and after the freezing‐thawing tests. The results showed that UHPC possessed very excellent freezing‐thawing resistance due to its dense microstructure. After the freezing‐thawing action, cracks occurred and were prone to initiate at the sand‐paste interface in the UHPC matrix. MIP results also indicated that cracks appeared in the UHPC matrix after the freezing‐thawing action. The number of defects that can be seen by X‐ray CT increased in UHPC after the freezing‐thawing action as well. The mismatch of the thermal expansion coefficients of the aggregate and the paste is considered to be the reason for the cracking at the sand‐paste interface. The steel fibers in UHPC inhibited the propagation of cracks in the matrix and improved the freezing‐thawing performance of UHPC.