Navegando por Autor "CUNHA, Rodrigo Rodrigues da"

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Emprego de Resíduo de Silício Metálico como Material Pozolânico na Produção de Cimento Portland Composto
(Universidade Federal do Pará, 2022-12-19) CUNHA, Rodrigo Rodrigues da; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
Civil construction, despite being an extremely important sector for the country's economic development, consumes a very significant amount of natural raw materials, in addition to being responsible for most of the consumption of cement produced in the world. The production of this material, in turn, causes many environmental impacts, resulting mainly from the sintering stage of clinker (main constituent of cement), which causes the emission of thousands of tons of CO2 into the atmosphere. In this sense, several studies have been carried out in order to point out an alternative material that can be used as a mineral addition to cement instead of clinker. Much of this research has sought to study the use of additions manufactured from the use of industrial waste. Given this context, the present work aims to analyze the behavior of a modified Portland cement of the CPIIZ-32 type, produced with partial replacement of clinker, by a residue from the pre-separator of the ferrosilicon - metallic silicon manufacturing process. - from an industry located in Breu Branco/PA. Therefore, at first, the physical and chemical characterization of the residue in natura and processed form was carried out, through the milling process, from the specific mass, FR-X, DR-X and activity index tests. pozzolanic with lime and cement. Then, 5 (five) blends of composite cement were formulated with different contents of ground silicon metal residue to analyze the mechanical behavior at 28 and 90 days of curing. Finally, a comparison was made of the physical-mechanical performance of the mortars produced with the use of modified cement and commercial cement of the CPIIZ-32 type. The results showed that the metallic silicon residue, after going through a pre-benefiting process (grinding for a period of 60 minutes) obtains properties consistent with the requirements stipulated by NBR 12653 (ABNT, 2014) to be considered as a pozzolanic addition. The use of this by-product for this purpose can generate enormous environmental benefits, reducing the impacts resulting from the clinker production stages, as well as being a viable alternative for the reverse logistics of this material, since the generating companies still do not have any form of reuse for this residue.
Desconhecido
Emprego de resíduo de silício metálico na produção de cimento portland composto
(Universidade Federal do Pará, 2017-12-19) CUNHA, Rodrigo Rodrigues da; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
The reuse of industrial waste and alternative raw materials in construction is fundamental to sustainable development with reduced consumption of natural resources and CO2 emissions. In this line, the present study contemplates the use of a powdered waste, originating from the production of metallic silicon, which is designated as pre-separator residue. In this way, the objective of this research is to produce and evaluate properties of Portland cement composite CP II-E with the addition, during its manufacture, of metallic silicon industrial residue after calcination. For this purpose, the residue was used in partial replacement to blast furnace slag, in mass contents of 30%, 50% and 70%, in addition to the reference situation, in which no silicon residue was added to the cement (0%). Cement properties, produced with residues, were evaluated for their chemical composition, mineralogical, physical parameters (fineness, picking times, fire loss and insoluble residue), compressive strength, water absorption, absorption by capillarity, microscopic techniques and analytical techniques (DR-X, chemical composition and thermal analyzes of TG / DTG). As results, there were no significant differences in the physical parameters of the cements produced. Cement mortars produced with higher residue contents (70% and 50%) had the highest values of compressive strength and lower values of capillary water absorption, voids index and water absorption by capillarity than mortars produced with standard cement ( without siliceous residue). The same was not observed for cement mortars with 30% silicon residue. Analytical techniques of scanning electron microscopy images indicated a more closed porosity for cement mortars in the contents of 70% and 50% of cement with residue. Thus, as a conclusion, the utilization of the residue studied as partial replacement material of granulated slag in composite cement type "E" is technically and environmentally feasible.