Portland Cement
Mostrando 37-48 de 285 artigos, teses e dissertações.
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37. Cinza de biomassa rica em calcário como material carbonático em sistemas cimentícios de base Portland
Resumo O uso de materiais alternativos, em substituição ao clínquer, tem sido amplamente estudado, a fim de reduzir custos e minimizar os danos ambientais causados pela produção do cimento Portland. Investigou-se a influência do uso da cinza de algaroba (Prosopis juliflora), material rico em carbonato de cálcio, nos mecanismos de hidratação e forma�
Cerâmica. Publicado em: 2019-01
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38. Evaluation of Portland pozzolan blended cements containing diatomaceous earth
Abstract Clinker replacement by supplementary cementitious materials (SCMs) is one strategy to reduce CO2 emissions of cement industry. Diatomaceous earth, a natural pozzolan, has been used as SCM. So, this study aimed to evaluate two Portland pozzolan blended cements with distinct content of diatomaceous earth (16DE and 49DE) and compare then with a high cl
Cerâmica. Publicado em: 2019-01
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39. Utilization of gypsum from construction and demolition waste in Portland cement mortar
Abstract Civil construction generates the largest amount of construction and demolition waste (CDW), most of which is not reused and is discarded as inert waste in landfills. The purpose of this study was to evaluate the feasibility of reusing gypsum recovered from CDW in the preparation of mortar. This material was examined to determine its specific mass, m
Cerâmica. Publicado em: 2019-01
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40. Impacto do uso de resíduo de vermiculita no estado endurecido de argamassas
Resumo No processo de beneficiamento da vermiculita é gerado um resíduo fino para o qual atualmente ainda não foi desenvolvida uma aplicação que possibilite a utilização em larga escala. Uma alternativa que vem sendo estudada é a associação com cimento Portland em composições de argamassas e concretos, em função da composição química do res�
Cerâmica. Publicado em: 2019-01
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41. Síntese e caracterização das fases minerais C3S, C2S, C3A e C4AF para utilização em cimento tipo Portland
Resumo As principais fases contidas no cimento Portland são 3CaO.SiO2 (C3S), 2CaO.SiO2 (C2S), 3CaO.Al2O3 (C3A) e 4CaO.Al2O3.Fe2O3 (C4AF). No processo industrial estas apresentam incorporações de outros elementos que dependem das matérias-primas e dos combustíveis utilizados na queima. O uso das fases puras auxilia na compreensão dos fenômenos envolvid
Cerâmica. Publicado em: 2019-01
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42. Effects of pre-treatment of Curauá fibers on compatibility with portland cements
ABSTRACT There has been ever growing interest in the construction industry in using lighter, eco-friendly and sustainable materials, while maintainingthe desirable mechanical properties. The objective of the present work was to evaluate the effects of pre-treatments on chemical compatibility between Curauá fiber (Ananas erectifolius) and Portland cement. In
Matéria (Rio J.). Publicado em: 18/10/2018
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43. Retracción química de pastas de cemento con incorporación de metacaolín
Abstract This study shows the influence of partial replacement of Portland cement by metakaolin in the hydration reactions and chemical shrinkage of cementitious pastes. For this, pastes were prepared using metakaolin replacements of 5, 10 and 20% by mass, and a reference paste, using a constant water/solid ratio of 0,5. Chemical shrinkage was measured conti
Ambient. constr.. Publicado em: 2018-09
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44. Particle Sizes and Wood/Cement Ratio Effect on the Production of Vibro-compacted Composites
ABSTRACT The aim of this study was to evaluate the influence of particle size and the wood/cement ratio on the physical and mechanical properties of vibro-compacted wood-cement composites. The effects of three different particle sizes (diameter between 1.4-2.36 mm; 2.36-4 mm; and 4-9.56 mm) and wood:cement ratios of 1:2.75, 1:2 and 1:1.5 on wood-cement comp
Floresta Ambient.. Publicado em: 30/07/2018
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45. Monitoring reinforcement corrosion of concretes designed for nuclear facilitie
ABSTRACT The facilities designed for the peaceful activities of nuclear energy are made with different materials, among them, reinforced concrete. This material, in addition to being structural, is a barrier for isolation and confinement from the environment of the radioactive materials. One of its degradation mechanisms is the corrosion of the reinforcement
Matéria (Rio J.). Publicado em: 19/07/2018
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46. Dynamic Properties of High Volume Fly Ash Nanosilica (HVFANS) Concrete Subjected to Combined Effect of High Strain Rate and Temperature
Abstract The study aims to determine the dynamic properties of high volume fly ash nanosilica (HVFANS) concrete exposed to strain rates between 30.12 to 101.42 s-1 and temperatures of 25, 400, and 700 oC by using split Hopkinson pressure bar (SHPB) machine. The static and dynamic compressive strengths of HVFANS concrete were slightly lower than plain concre
Lat. Am. j. solids struct.. Publicado em: 23/04/2018
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47. Comportamiento del residuo de vidrio molido en cementos mezcla: Estudio comparativo con microsilice
ABSTRACT Due their high content of silica in an amorphous state the glass, in theory, can behave as pozzolanic material when are finely ground. This opens up an interesting way of reusing these materials in the Portland cement industry (CP), especially considering that solid urban waste (RSU) in Argentina contains between 3 and 5% by weight of glass. This pa
Matéria (Rio J.). Publicado em: 05/03/2018
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48. Evaluation of Influence of Salt in the Cement Hydration to Oil Wells
The influence of NaCl salt in the hydration of the Portland cement paste class G was studied using a Non Conventional Differential Thermal Analysis (NCDTA) on the first 24 hours of cement hydration. The mass of salt used corresponds to 0, 5, 10, 15 and 20% of mass of water used in the preparation of the pastes. The water/cement ratio (w/c) remained constant,
Mat. Res.. Publicado em: 08/01/2018