EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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3 resultados
Resultados da Pesquisa
Item Mechanical, rheological and morphological analysis of cement-based composites with a new LAS-based air entraining agent.(2017) Mendes, Júlia Castro; Moro, Taís Kuster; Figueiredo, Aline Santana; Silva, Keoma Defáveri do Carmo e; Silva, Gabriela Cordeiro; Silva, Guilherme Jorge Brigolini; Peixoto, Ricardo André FiorottiThe air-entraining admixtures (AEA) consist of surfactant compounds, as do washing-up liquids. Washing-up liquids are products widely available, non-toxic and biodegradable. This work proposes the use of an anionic surfactant from washing-up liquids, Linear Alkyl Benzene Sodium Sulfonate (LAS), as AEA. Mechanical, physical and rheological properties of mortars comprising LAS were compared to ones with commercial admixture and one without any. The morphological aspects of the air-entrained matrix were also evaluated, and associated to its properties. Results indicate that the LAS-based AEA is an effective air-entraining agent. Thus, the present work seeks to disclose this new biodegradable highperformance potential AEA, as well as to improve the comprehension of the effects of AEAs in cementbased composites.Item Technical and environmental feasibility of interlocking concrete pavers with iron ore tailings from tailings dams.(2017) Sant’ana Filho, Joaquim Nery; Silva, Sidney Nicodemos da; Silva, Gabriela Cordeiro; Mendes, Júlia Castro; Peixoto, Ricardo André FiorottiThe present paper evaluates the technical and environmental feasibility of using iron ore tailings (IOTs) as fine aggregate in the production of interlocking concrete blocks. Initially, environmental, chemical, and physical characterizations of the tailings were carried out. Pavers with IOTs replacing natural aggregate in proportions from 10 to 80% were manufactured and subjected to physical analyses (expansion, porosity, and water absorption), environmental analyses (leaching and dissolution), as well as mechanical tests (compressive strength and surface abrasion). Test results of the IOT pavers were compared to conventional ones and to standard limits. The IOT pavers showed physical and mechanical properties significantly similar, or superior, to the conventional ones, and all within the requirements for regular traffic. Therefore, IOT are technical and environmentally feasible to be used in the production of precast concrete blocks. This reuse also contributes to the reduction of the social and environmental impacts associated to tailings dams.Item Using iron ore tailings from tailing dams as road material.(2016) Bastos, Lucas Augusto de Castro; Silva, Gabriela Cordeiro; Mendes, Júlia Castro; Peixoto, Ricardo André FiorottiThe present work aims to evaluate the feasibility of iron ore tailings from tailing dams as an alternative material for road infrastructure. The iron ore tailings were characterized according to their chemical, mineralogical, environmental, and physical properties. Subsequently, the tailings were chemically stabilized using cement, lime, or steelmaking slag as binder. The tailing-cement, tailing-lime, and tailing-slag mixtures studied consisted of 1, 2, 5, and 10% binder content, each. The characterization methodology included chemical and mineralogical analysis through X-ray fluorescence and diffraction; environmental analysis with leaching and dissolution tests; evaluation of compaction curves; California bearing ratio (CBR) tests and expansion assessment; compressive strength, with curing in moisture chamber or at open air; water absorption; and evaluation of durability of the mixtures. Overall, the results indicate that the iron ore tailings are a feasible solution for use as layers for road paving, once chemically stabilized. The cement is the most efficient stabilizer among the studied binders. The slag-tailing sample did not endure the durability cycles; thus, further research is required to ensure its technical feasibility. DOI: 10.1061/ (ASCE)MT.1943-5533.0001613. © 2016 American Society of Civil Engineers.