Resumen de Microstructural analysis and performance evaluation of graphene oxide-enhanced cement mortar and concrete: implications for mechanical strength and durability
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 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, promotes the formation of additional hydration products, the main chain length 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 chloride penetration, and carbonation, and water absorption 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.
