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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Resultados da Pesquisa

Agora exibindo 1 - 2 de 2
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    Macroporous mortars for laying and coating.
    (2019) Mendes, Júlia Castro; Pinto, Paloma Bárbara; Silva, Henrique Emanuel Américo da; Barreto, Rodrigo Rony; Moro, Taís Kuster; Peixoto, Ricardo André Fiorotti
    The envelope of a building is responsible for its physical protection against external agents, including humidity and temperature. Thus, the present work seeks to evaluate the effect of air entraining admixtures (AEA) in mortars for laying and coating to improve their physical and thermal performances. The AEA generates macropores, interrupting the system of canaliculi that allows the capillary absorption of water. The AEA used is based on biodegradable surfactant molecules of Linear Alkyl Benzene Sodium Sulfonate. Results compare physical tests (water absorption, capillary coefficient, specific gravity, and mechanical strength), and thermal evaluation (thermal conductivity and specific heat) from two mortars mixtures with varying levels of AEA. Scanning electron microscopy (SEM) of the pore system were also analysed. All mixtures studied presented higher workability and cohesion, reduced thermal conductivity, decreased specific heat, and a reduction in the effects of water absorption, capillary elevation and specific gravity (density). In this sense, the durability of mortars to humidity effect is potentially improved, along with several other properties. Therefore, this work seeks to contribute to the quality of built environments, as well as to promote the technological development of cement-based composites.
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    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 Fiorotti
    The 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.