Dissertações em Engenharia de Barragem e Gestão Ambiental (Mestrado) - PEBGA/NDAE/Tucuruí

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/9396

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Agora exibindo 1 - 2 de 2

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Análise da adição de resíduos siderúrgicos em matrizes cimentícias para concreto massa
(Universidade Federal do Pará, 2021-12-17) BONFIM, Francirene Pereira; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
During the steel production process, industrial waste is generated, including granulated blast furnace slag and balloon powder, generated in the pig iron production stage; and electric arc furnace dust, obtained in the production stage of the steelworks. In the northern region, the highlight in steel production is SINOBRAS - Siderúrgica Norte Brasil SA, located in the municipality of Marabá-PA, which also experiences the problem of waste disposal, and therefore has been supporting partnerships with educational institutions in the region for expansion of destination alternatives. Thus, this research aims to evaluate the influence of waste from the SINOBRAS industry, granulated blast furnace slag (GBFS), balloon powder (BP) and electric arc furnace dust (EAFD) in cementitious matrices, predicting applications in mass concrete for dams . The research methodology was carried out in two stages, the first being directed towards the study of waste, analyzing its physicochemical and mineralogical characteristics, the pozzolanicity potential according to ABNT NBR 12653:2015, and classification according to the type of solid waste according to ABNT NBR 10004:2004. The second stage of the methodology comprised the analysis of cement matrices composed of the residues, combined with GBFS (GBFS70+BP30; GBFS50+EAFD50), in order to increase the potential performance of the properties verified for mass concrete, with compressive strength tests being carried out, setting times, heat of hydration and alkali-aggregate reaction. It was concluded in the residue study stage that BP and EAFD did not present pozzolanic properties, indicating that they are not interesting for applications of cementitious materials. As for the classification, the GBFS and the BP were classified as class IIA waste - non-hazardous and non-inert, while the EAFD was classified as class I - hazardous. In the second stage of the study, the EAFD combined with the GBFS showed pozzolanicity and the BP, even after combination, remained non-pozzolanic. Evaluating the combined cementitious matrices, the (GBFS50+EAFD50) obtained satisfactory results in all properties, since it promoted a reduction of heat of hydration by 7% and, consequently, an increase in setting times (about 6 hours), and mitigation of expansion reactions, in aggregates gravel and sand by 49%. and 75% respectively. Therefore, the use of the matrix GBFS50+EAFD50, in the studied content, can be a technically viable alternative for applications in mass concrete for dams, being necessary, however, to advance in the research, aiming to produce the concrete traces composed by the matrix combined (GBFS50+EAFD50).
Acesso aberto (Open Access)
Dosagem experimental de concreto massa com adição de sílica ativa aplicado em barragem
(Universidade Federal do Pará, 2017-11-10) SOUZA, Grazielle Tigre de; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
The study of concrete dosage for large constructions, specifically of dams, has its own peculiarities due to the large volumes involved, intensifying the care with the supply and quality of materials used for these concretes, compositions with pozzolan additions are generally used in order to reduce the heat of hydration. In this sense, the main objective of this research is the elaboration of a mix design of concrete with the substitution of 8% of the cement per silica fume, the experimental study of the mix design was based on the Method of the Fineness Module of the Aggregates. To meet the proposal of this research, the methodology based primarily on the characterization of concrete constituent materials (fine and coarse aggregates, and silica fume), concrete mix design study by the Method of the Fineness Module (MFM) and subsequent analysis of the properties of the concrete mass obtained, making it possible to elaborate the concrete mix design, according to the requirements specified in the design of hydroelectric power plant structures. In this sense, with regard to the characterization of the aggregates, the results demonstrated the feasibility of the use of these in the production of concrete for dams. In relation to cement and silica fume the characteristics of these materials attend the normative requirements. The experimental dosage based on the MFM method, made it possible to compose the dosage graphs needed to define the mix design of concretes and consequently the verification of their applications in dams. It can be affirmed, thus, that the MMF approach developed in this research can be considered an important contribution, for the dissemination of the dosage methodology for concrete application in dams.

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