The effect of graphene oxide (GO) on the mechanical strengths and durability of cement composites was researched by preparing GO-modified cement mortars. Thermogravimetric analysis (TGA) and nuclear magnetic resonance (²⁹Si MAS-NMR) were performed on the cement paste to evaluate the influence of GO on the hydration process and chain structure of calcium-silicate-hydrate (C–S–H) gels. TGA revealed that the high GO dosage increased the content of C–S–H by 5.46% compared with the control at 28 days. Similarly, ²⁹Si-NMR improved the hydration degree and main chain length (MCL) in GO-modified samples at 28 days. The GO led to increases of 2.54% and 7.01% in the hydration degree and MCL, respectively, compared with the control at 28 days. These findings underscore the multifaceted role of GO in improving the mechanical properties and durability of cement composites. Mechanical strength tests, such as compressive and flexural tests, were conducted on cement mortars. The optimal dosage of GO increased the compressive strength by 9.02% after 28 days. Furthermore, the flexural strength of cement mortars with the combination of GO and superplasticizer (SP) after 28 days increased by 21.86%, compared with reference mortar. The impact of GO proved to be more pronounced and beneficial in the durability tests, suggesting that GO can enhance the microstructure through hydration products to create a dense and interconnected microstructure.

The incorporation of graphene oxide into cementitious materials offers a promising avenue to enhance their performance. This study focuses on the microstructural effects of graphene oxide on cement paste, as well as its impact on the mechanical properties and durability of mortar and concrete. Doses of graphene oxide at 0.0005%, 0.005%, and 0.05% were used in cement paste and mortar, while doses of 0.0005% and 0.005% were employed in concrete. The objective of this research is to understand how graphene oxide influences hydration processes, the formation of hydration products, and the long-term performance of these materials. For the cement paste, a detailed microstructural analysis was conducted using techniques such as thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface analysis, and Raman spectroscopy. The results show that graphene oxide significantly improves the degree of hydration, the main chain length, promotes the formation of additional hydration products, and densifies the microstructure. These microstructural improvements contribute to enhanced mechanical performance, although the impact of graphene oxide on mechanical properties is more evident at advanced ages. Regarding mortar, two series were evaluated: one without superplasticizer (water/cement ratio of 0.5) and another with superplasticizer (water/cement ratio of 0.35). While graphene oxide demonstrated improvements in mechanical properties, especially at advanced ages, these improvements were relatively moderate compared to its effect on durability tests. Graphene oxide significantly improved the material's resistance to water absorption, chloride penetration, and carbonation, resulting in greater resistance to environmental degradation. In concrete, doses of graphene oxide at 0.0005% and 0.005% were evaluated to assess their effect on mechanical properties and durability, including accelerated corrosion tests. Similar to mortar, graphene oxide showed moderate improvement in compressive strength but had a much clearer impact on durability, enhancing concrete's resistance to corrosion, which is crucial for its longevity in aggressive environments. In summary, this research demonstrates that graphene oxide is an effective additive for improving the durability properties of cementitious materials, with a more pronounced impact on corrosion resistance and environmental degradation. While its effects on mechanical properties are moderate, especially at advanced ages, graphene oxide offers great potential for developing more sustainable and durable construction materials. This study opens up new opportunities to optimize graphene oxide doses and explore combinations with other additives to maximize the performance of these materials. RESUMEN La incorporación de óxido de grafeno en materiales cementicios ofrece una vía prometedora para mejorar su rendimiento. Este estudio se centra en los efectos microestructurales del óxido de grafeno en la pasta de cemento, así como en su impacto en las propiedades mecánicas y la durabilidad del mortero y el hormigón. Se utilizaron dosis de óxido de grafeno de 0.0005%, 0.005% y 0.05% en la pasta de cemento y el mortero, mientras que en el hormigón se emplearon dosis de 0.0005% y 0.005%. El objetivo de esta investigación es comprender cómo influye el óxido de grafeno en los procesos de hidratación, la formación de productos de hidratación y el rendimiento a largo plazo de estos materiales. Para la pasta de cemento, se realizó un análisis microestructural exhaustivo utilizando técnicas como el análisis termogravimétrico (TGA), la resonancia magnética nuclear (RMN), la difracción de rayos X (DRX), la microscopía electrónica de barrido (SEM), el análisis de superficie Brunauer-Emmett-Teller (BET) y la espectroscopía Raman. Los resultados muestran que el óxido de grafeno mejora el grado de hidratación, la longitud de las cadinas y promueve la formación de productos de hidratación adicionales, densificando la microestructura. Estas mejoras microestructurales contribuyen a un rendimiento mecánico mejorado, aunque el impacto del óxido de grafeno en las propiedades mecánicas es más evidente a edades avanzadas. En cuanto al mortero, se evaluaron dos series: una sin superplastificante (relación agua/cemento de 0.5) y otra con superplastificante (relación agua/cemento de 0.35). Si bien el óxido de grafeno mostró mejoras en las propiedades mecánicas, especialmente a edades avanzadas, estas mejoras fueron relativamente moderadas en comparación con su efecto en los ensayos de durabilidad. El óxido de grafeno mejoró significativamente la resistencia del material a la absorción de agua, la penetración de cloruros y la carbonatación, resultando en una mayor resistencia a la degradación ambiental. En hormigón, las dosis de óxido de grafeno de 0.0005% y 0.005% fueron evaluadas para determinar su efecto en las propiedades mecánicas y de durabilidad, incluidas pruebas aceleradas de corrosión. Al igual que en el mortero, el óxido de grafeno mostró una mejora moderada en la resistencia a compresión, pero un impacto mucho más claro en la durabilidad, mejorando la resistencia del hormigón a la corrosión, lo que es crucial para su longevidad en ambientes agresivos. En resumen, esta investigación demuestra que el óxido de grafeno es un aditivo eficaz para mejorar las propiedades de durabilidad de los materiales cementicios, con un impacto más claro en la resistencia a la corrosión y la degradación ambiental. Aunque sus efectos en las propiedades mecánicas son moderados, especialmente a edades...

The effect of graphene oxide (GO) on mechanical strengths and durability of cement composites has been studied by preparing GO-modified cement mortars. Thermogravimetric analysis (TGA) and nuclear magnetic resonance (29Si MAS-NMR) were performed on the cement paste to research the influence of GO on the hydration process and chain structure of calcium-silicate-hydrate (C-S-H) gels. In addition, mechanical strength test, such as compressive and flexural, were performed on cement mortars. The addition of GO at 0.05 wt.% (by weight of cement) increased the compressive strength by 9.02% after 28 days. Furthermore, the flexural strength of cement mortars with 0.05 wt.% GO and superplasticizer (SP) after 7 and 28 days increased by 12.26% and 21.86%, respectively, compared with reference mortar. At the same time, the effect of GO proved to be more significant and effective in the durability tests, suggesting that GO can enhance the microstructure through hydration products to create a highly cross-linked micro structure.

Graphene oxide (GO), a nanomaterial with outstanding properties, has attracted growing attention in civil engineering for its potential to enhance cementitious composites. Its oxygen-containing functional groups improve dispersion within the cement matrix, promoting better interaction with hydration products. This study investigates the influence of low GO dosages on the microstructure and durability of cement-based materials. Three mixtures were prepared: a reference mix without GO, and two mixes incorporating 0.0005% and 0.005% GO by weight of cement.Results show that GO significantly improves the microstructure by acting as a nucleation site, refining pore structure, and controlling crack propagation. These effects lead to a denser and more homogeneous matrix with reduced porosity. Consequently, durability-related properties are enhanced, including resistance to water penetration, oxygen permeability, carbonation, and chloride ingress. Compared with the reference mix, oxygen permeability decreased by up to 95%, while water penetration and carbonation depth were also notably reduced. Chloride diffusion coefficients also decreased by up to 30%.Microstructural analysis using SEM-EDS confirmed these improvements, revealing crack deflection around GO sheets, pore filling by hydration products, and a reduced Ca/Si ratio in the C–S–H gel. Overall, the findings demonstrate that significant durability gains can be achieved with GO content much lower than that commonly reported, offering advantages in cost-effectiveness and practical applications.

This study examines the effects of graphene oxide (GO) on the hydration behaviour, microstructure, and mechanical properties of Portland cement-based materials. Cement pastes and mortars incorporating GO at dosages of 0.0005%, 0.005%, and 0.05% by weight of cement were analysed through thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS), and mechanical strength testing. TGA results indicate that GO exerts a time-dependent influence on cement hydration. At early ages, GO slightly retards hydration, evidenced by lower C–S–H and CH content in GO-containing samples at 2 and 7 days, attributed to water adsorption by its oxygen-containing functional groups. At later curing ages (28–90 days), TGA results show greater C–S–H and CH weight losses in GO-modified samples compared to the reference, consistent with GO acting as a water reservoir and nucleation site. XRD and SEM results confirm that GO incorporation leads to a reduction in CH crystal size, a denser and more homogeneous microstructure, and fewer pores and microcracks. Mechanical tests revealed that GO contents of 0.0005% and 0.05% produced the most significant improvements, with increases of up to 9% in compressive strength and 16% in flexural strength at 90 days compared with the control specimens. In summary, the incorporation of low GO dosages effectively refines cement microstructure, enhances long-term hydration, and improves mechanical performance, demonstrating GO’s potential as a strength- and durability-enhancing nanomaterial for cementitious composites.