Admixture
Mostrando 1-12 de 190 artigos, teses e dissertações.
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1. Evaluation of the influence of sodium and magnesium lignosulfonates on the hydration kinetics of cementitious paste
Abstract Motivated by their low cost, lignosulfonate-based water reducers are the most used type of admixture in the concrete industry worldwide. Due to the plurality of types of lignosulfonates (LSs) and the recent update to the Brazilian standard for admixtures for concrete, the objective of this work was to investigate the impact of sodium (Na-LS) and mag
Cerâmica. Publicado em: 2022
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2. Characterization of sugarcane bagasse ash (SBA) and its evaluation for use in alkali-activated slag mixtures
Abstract This work proposed to incorporate the sugarcane bagasse ash (SBA) with a high content of organic matter (loss on ignition of 35.87%) in alkali-activated mixtures with blast furnace slag. After grinding SBA, replacement ratios of 10%, 20%, and 30% of the ground ash were used for the flowability evaluation. The mixtures containing 20% and 30% showed a
Cerâmica. Publicado em: 2021-03
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3. Consumption of superplasticizer admixture for different cements and their binder efficiency
Resumo Foram estudados, em cimentos e fillers calcários, os teores ótimos de superplastificante (base policarboxilato éter), determinados através de reometria rotacional, e estimados seus efeitos nos impactos ambientais de concretos. Ensaios de espalhamento de argamassas em mesa de consistência foram feitos para determinação da redução de água e es
Rev. IBRACON Estrut. Mater.. Publicado em: 13/12/2019
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4. Liaisons dangereuses: cross-border gene flow and dispersal of insecticide resistance-associated genes in the mosquito Aedes aegypti from Brazil and French Guiana
BACKGROUND In recent years, South America has suffered the burden of continuous high impact outbreaks of dengue, chikungunya and Zika. Aedes aegypti is the main mosquito vector of these arboviruses and its control is the only solution to reduce transmission. OBJECTIVES In order to improve vector control it is essential to study mosquito population geneti
Mem. Inst. Oswaldo Cruz. Publicado em: 23/09/2019
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5. Shrinkage and porosity in concretes produced with recycled concrete aggregate and rice husk ash
Resumo O emprego de agregado reciclado de concreto (ARC) para a produção de novos concretos é uma alternativa interessante para mitigar impactos ambientais. O ARC pode aumentar a porosidade e impactar negativamente as propriedades do concreto. A cinza de casca de arroz (CCA), empregada como material cimentício suplementar, pode mitigar estes efeitos. Est
Rev. IBRACON Estrut. Mater.. Publicado em: 18/07/2019
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6. Concretos com agregados reciclados de resíduos de construção e demolição e adições minerais: uma análise bibliográfica
RESUMO Os impactos ambientais causados pela produção do concreto precisam ser reduzidos para torná-lo um material mais sustentável. O uso de agregados reciclados em substituição aos agregados naturais e das adições minerais em substituição parcial ao cimento são alternativas que podem tornar o concreto um material com menor carga de poluentes asso
Matéria (Rio J.). Publicado em: 10/06/2019
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7. Influência do uso de cinza volante na elevação adiabática de temperatura e resistência à compressão de concretos
RESUMO A construção de grandes edifícios tem requerido a execução de blocos de fundação de grandes dimensões, com volumes que chegam a milhares de m3 de concreto. Em geral, estas estruturas são executadas em concretos autoadensáveis e/ou de altas resistências, resultando em elevados consumos de aglomerante. Nesses casos, o emprego de cinza volante
Matéria (Rio J.). Publicado em: 10/06/2019
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8. Effects of using chemical admixture with nanosilica in the consistency and mechanical strength of concrete
Resumo O desempenho do concreto depende do seu comportamento nos estados fresco e endurecido, haja vista que a trabalhabilidade corrobora para os processos de transporte e aplicação do material, enquanto a resistência mecânica garante eficácia e funcionalidade estrutural. Geralmente, estudos de misturas com nanosílica (nS) são voltados para análise d
Rev. IBRACON Estrut. Mater.. Publicado em: 20/05/2019
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9. Pharmacogenetic implications in the management of metabolic diseases in Brazilian populations
Dyslipidemia, diabetes, obesity and hypertension are common metabolic diseases. In the last decades, unhealthy lifestyle and aging have leads to an increased incidence of these diseases, increasing morbidity and mortality by cardiovascular causes. The treatment of metabolic diseases includes life-style interventions as healthy diet and physical exercise, as
Braz. J. Pharm. Sci.. Publicado em: 08/11/2018
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10. Fresh properties of HPSCC containing SRA and expansive admixtures
ABSTRACT Shrinkage-reducing admixture (SRA) and expansive admixture (EXA) were used in high performance self-compacting concrete (HPSCC) to mitigate autogenous shrinkage. In order to evaluate the fresh properties of concretes, the rheological parameters were determined in a ICAR rheometer at 10, 25, 40, 60 and 90 min. The flow behavior of the mixtures was de
Matéria (Rio J.). Publicado em: 18/10/2018
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11. Diallel analysis and genetic differentiation of tropical and temperate maize inbred lines
Abstract This study aimed to evaluate hybrids obtained by the cross among temperate × tropical elite maize lines, and to determine the genetic diversity and population differentiation of these inbred lines. Forty-nine hybrids were evaluated for seed yield, plant and ear heights, and for severity of Phaeosphaeria maydis and Exserohilum turcicum in four envir
Crop Breed. Appl. Biotechnol.. Publicado em: 2018-03
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12. Microstructure and hardness of cement pastes with mineral admixture
ABSTRACT Portland cement pastes are highly heterogeneous material and exhibits heterogeneous features over a wide range of length scales. Mechanical properties of microstructure can be determined using depth-sensing indentation. Coupled indentation/SEM technique can be used to location the indents and provides a way to determine the mechanical properties of
Matéria (Rio J.). Publicado em: 22/06/2017