Estudo da viabilidade de incorporação do óxido de grafeno rico em carbonila ao concreto sob óticas das propriedades mecânicas

Abstract

The concrete is a construction material largely applied in Brazil and worldwide. This material is constantly evolving, with better and better properties, being more resistant and more effective by contributing to the development of civil construction sector, in wich higher and architecturally bolder buildings are observed over the years. In addition to providing the development of the construction sector, concrete innovations are directly connected to its technology. A large portion of its development is due to additions incorporated to the mixture. It is reported in the literature that de addition of Graphene Oxide (GO) to the concrete is capable of enhancing its properties due to the excellent electrical, thermic, mechanical and optic characteristcs of the nano-material. This research’s goal is to study the incorporation of the carbonyl-rich graphene oxide (CGO) to the concrete, by determining its optimal dosage, and comparing the obtained results with the ones provided in literature related to the GO. This variation of the graphene oxide, developed by the nanoscience and nanotechnology group at UFJF, has distinct properties that were never before incorporated to cement matrices. In order to develop the work the concentrations of 0,02%, 0,03% and 0,05% of CGO in relation to the weight of cement were tested and compared to the properties of a reference sample that has no addition of this material. Experiments were performed to determine the bulk density, void index, water absorption through immersion, ultrasonic pulse velocity, axial compression strength, tensile strength by diametral compression and static and dynamic modulus of elasticity. Samples with a concentration of 0,02% of CGO demonstrated excellent results, with a 33,2% increase in compressive strength, 17,9% increase in tensile strength, 28,1% increase in static modulus of elasticity and 32,7% increase in dynamic modulus of elasticity. Additionally, there was a reduction of 36,2% in void index, 1,2% in bulk density and 35,7% in water absorption. The samples with a concentration of 0,03% of CGO also showed gains in compressive strength, tensile strength and modulus of elasticity, but undesired increases were observed in void index and water absorption. On the other hand, samples with a concentration of 0,05% of CGO did not yield promising results, which may be attributed to the greater difficulty in dispersing the nano-material in the mixture. Therefore, CGO exhibited results as good as those reported in the literature for GO, and in most cases, it demonstrated superior performance. Keywords: Technology; Concrete; Carbonyl-rich graphene oxide.