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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2 resultados
Resultados da Pesquisa
Item Use of steel slag and LAS-based modifying admixture in obtaining highly eco-efficient precast concrete products.(2023) Martins, Ana Carolina Pereira; Carvalho, José Maria Franco de; Duarte, Matheus do Nascimento; Pedroti, Leonardo Gonçalves; Ribeiro, José Carlos Lopes; Peixoto, Ricardo André FiorottiThis paper presents a study on improving the eco-efficiency of no-slump concrete for precast elements using Basic Oxygen Furnace Slag (BOFS). Recycled BOFS powders and aggregates have been produced to obtain mixtures with better particle size distribution and improved packing density based on a particle packing method. A comprehensive experimental investigation was carried out on mixtures with different cement contents (5%, 10%, and 15% vol.) and compaction energy levels (6, 10, and 20 blows in a sand rammer). A modifying admixture based on Linear Alkyl Benzene Sodium Sulfonate (LAS) has also been evaluated as a workability and cohesiveness enhancer for steel slag concretes. In addition, concrete eco-efficiency was evaluated by measuring the binder intensity (bi) and waste consumption. The highest compaction energy provided packing densities ranging from 0.78 to 0.80, and BOFS aggregates led to better mechanical performances. The BOFS concrete containing 15% cement obtained the best strength (52.1 MPa) and bi value (7.0 kg/m3 /MPa), with a waste consumption of 2356.57 kg/m3 . The mixture with the lowest cement consumption (5% - 121.56 kg/m3 ) and the highest consumption of waste (2637.82 kg/m3 ) reached 16 MPa, delivering a bi of 7.6 kg/m3 /MPa.Item More eco-efficient concrete : an approach on optimization in the production and use of waste-based supplementary cementing materials.(2019) Carvalho, José Maria Franco de; Melo, Tainá Varela de; Fontes, Wanna Carvalho; Batista, Júnio Oliveira dos Santos; Silva, Guilherme Jorge Brigolini; Peixoto, Ricardo André FiorottiThis paper presents a study that includes increase in clinker replacement and waste consumption in cement-based composites. Techniques for performance optimization of waste-based supplementary cementing materials in densely packed matrices using basic oxygen furnace slag, iron ore tailings from a tailings dam, quartz mining tailings and quartzite mining tailings were evaluated. Powders with different particle size ranges were produced and characterized. A highly-packed sand-concrete reference mix was designed and six different mixtures with 10−60 vol% partial cement replacement were evaluated. The high binder efficiencies observed and physical-mechanical performances evidence the effectiveness of the proposal, expanding the concept of low-cost supplementary cementing materials and broadening the range of residual materials suitable for use in cement-based composites.