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.
Navegar
2 resultados
Resultados da Pesquisa
Item Eco-efficient steel slag concretes : an alternative to achieve circular economy.(2022) Costa, Laís Cristina Barbosa; Nogueira, Marcela Aguiar; Ferreira, Larissa Caroline; Elói, Fernanda Pereira da Fonseca; Carvalho, José Maria Franco de; Peixoto, Ricardo André FiorottiAnnually billions of tonnes of aggregates are extracted to apply in civil construction generating environmental impacts and energy consumption. So, based on circular economy principles applying residues as aggregates is a good solution to reduce the mining activity and to generate a more efficient destination for the residues. Thus, this research aims to evaluate the technical, economic, and environmental performance of concretes produced entirely with steel slag aggregates. The concretes were characterized through physical properties, as specific gravity, water absorption, compressive and tensile strength. Durability tests (expansibility) were also conducted. The authors analyzed the cost assessment and environmental impact of steel slag concrete production as well. The incorporation of steel slag increases the compressive and tensile strength of concrete, analyzed in different ages. Additionally, the steel slag does not present expansibility when confined in the concrete matrix. The entire replacement of natural aggregates for steel slag allowed to reduce in 31% the cement consumption, a decrease of 140 kg/m3 , for the same strength class. The environmental analysis showed that the incorporation of steel slag aggregates reduced the cement intensity of concrete and its impact. Regarding the cost assessment, the mixtures with steel slag presented a lower cost compared to the conventional one. These results indicate that steel slag aggregates could be used in a cleaner production of concrete, replacing natural aggregates with no injury. This research provides the feasibility of using steel slag aggregates in a cleaner and cheaper concrete production and contribute to the promotion of sustainable solutions for the construction sector through the circular economy principles.Item Compressive strength of reduced concrete specimens considering dimensional distortion of coarse aggregates.(2020) Azevedo, Carlos Felipe de; Carvalho, José Maria Franco de; Mendes, Júlia Castro; Castro, Arthur Silva Santana; Barreto, Rodrigo Rony; Peixoto, Ricardo André FiorottiThe present study investigates the mechanical behavior of small cylindrical specimens (£50 100 mm) in relation to the minimum standard size (£100 200 mm) recommended by ASTM and Brazilian codes. Statistical and dimensional analyses were performed for three different classes of compressive strength (20, 30, and 40 MPa), and four grades of coarse aggregates (Dmax 9.5, 12.5, 19, and 25 mm). To this purpose, the Student’s t-Test for two means and equations from the Similitude Theory were applied. The following evaluations were performed: a) influence of the dimensional distortion of aggregates on the compressive strength of small concrete specimens; b) analyses through hypothesis testing between strength means; c) the use of prediction coefficients with statistical reliability for correcting the dimensional distortion of aggregates; and d) influence of the wall effect for different specimen sizes and concrete mixes. The results showed that the reduced and the standard specimens have similar compressive strengths, despite the reduced ones having presented higher variability of results. Also, innovative quantitative results from Wall Effect analysis show agreement with the strength results and illustrate the phenomena from a new perspective.