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Search Results: 1 - 10 of 600750 matches for " Ruby Mejía de Gutierrez "
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Reuse of a residue from petrochemical industry with portland cement Reutilización de un residuo de la industria petroquímica como adición al cemento portland
Janneth Torres Agredo,Jenny J Trochez Serna,Ruby Mejía de Gutierrez
Ingeniería y Ciencia , 2012,
Abstract: In this article the possibility of using waste from the petrochemical industry,as partial replacement of Portland cement is studied, evaluating the presence of contaminants in the waste and the encapsulation, once it is con ned on the cement. This has been done, in order to nd a use to this residue without cause damage to the environment. This residue, called spent uid catalytic cracking catalyst (FCC), is mainly formed by a type Y zeolite, which is dispersing in an inorganic oxides matrix. The toxicity characteristic leaching proceeding was applied, in mortars adding with 20% of FCC as Portland cement replacement. The results showed that the residue does not represent a problem from the point of view of the leaching of elements, such as As, Pb, Zn, Cr, and La, which were below to the permissible limits. Additionally, the pozzolanic activity of FCC was evaluated according to ASTM C311, where the e ciency of the residue as pozzolanic addition is demonstrated. With the results the importance of reusing a residue of the petrochemical industry is emphasized, that decreases the amount of cement to be used and improves the mechanical resistance of the materials containing it. En el presente artículo se estudia la posibilidad de utilizar un residuo de la industria petroquímica, como sustitución parcial del cemento Portland, evaluando la presencia de elementos contaminantes en el residuo y su encapsulación, una vez se haya confinado con el cemento. Lo anterior, con el fin de determinar si su uso como material de construcción, puede o no causar un efecto negativo al medio ambiente. El residuo, denominado catalizador usado de craqueo catalítico (FCC), es un material que está compuesto por una zeolita tipo Y, dispersa en una matriz de óxidos inorgánicos. Se aplicó la técnica de TCLP (del inglés Toxicity Characteristic Leaching Procedure), en morteros adicionados con un 20%, de FCC con respecto a la cantidad de cemento. Los resultados mostraron que el catalizador no representa un problema desde el punto de vista de la lixiviación de elementos, tales como el As, Pb, Zn, Cr y La, los cuales estuvieron por debajo de los límites permisibles. Adicionalmente, se evaluó la actividad puzolánica del FCC, a partir de la norma ASTM C311, donde se demuestra la efectividad del residuo como adición cementicia. Con los resultados, se destaca la importancia de la reutilización de un residuo de la industria petroquímica, que además de lograr disminuir la cantidad de cemento a utilizar, mejora las resistencias mecánicas de los materiales que lo contienen.
Efecto del modo de obtención de la sílice amorfa a partir de la cascarilla de arroz en las propiedades de durabilidad del concreto armado.
Serguei Solarte,Michel Ospina,William Aperador,Ruby Mejía de Gutierrez
Scientia Et Technica , 2007,
Abstract: En este artículo se investigó el efecto que la ceniza de cascarilla de arroz tiene sobre las propiedades mecánicas y de durabilidad en el concretos adicionado. Para esto, se hicieron a 28 días de curado ensayos de resistencia mecánica, densidad y porosidad, penetración rápida del ión cloruro, espectroscopía de impedancia electroquímica y resistencia a la polarización. Los resultados demuestran que la ceniza disponible localmente aumenta la resistencia a compresión y reduce la permeabilidad ante agentes agresivos como el ión cloro sólo si se adiciona al concreto en partículas finamente molidas.
INFLUENCIA DE LA COMPOSICIóN MINERALóGICA DE LOS CAOLINES SOBRE EL DESEMPE?O DE MORTEROS ADICIONADOS CON MK
TORRES AGREDO,JANNETH; MEJíA DE GUTIéRREZ,RUBY;
DYNA , 2007,
Abstract: this work forms part of a research project, aiming at using metakaolin (mk) in concrete manufacture. this paper is focused on the performance of two types of metakaolin. origin kaolin and high purity commercial kaolin were used as raw materials which show a different mineralogical composition (48 and 97% of kaolinite). the pozzolanic activity of the metakaolin was evaluated according to astm c311 test and determining the amount of calcium hydroxide consumed during the pozzolanic reaction by termogravimetric analysis (tga). the properties of capillarity absorption and chloride permeability of cement mortars were determined. each mk was incorporated into the mortar in proportions of 10 and 20% by mass of cement. a better behaviour was verified for the mortars added by mk obtained from high purity kaolin; nevertheless with 20% of addition the difference between the properties of the mixtures with both different mk is minimal, which indicates a possibility of utilization of poor kaolin to produce this type of pozzolan.
Influencia de la composición mineralógica de los caolines sobre el desempe o de morteros adicionados con mk
JANNETH TORRES AGREDO,RUBY MEJíA DE GUTIéRREZ
DYNA , 2007,
Abstract: El presente trabajo forma parte de un proyecto de investigación, cuyo objetivo primordial fue la producción de Metacaolín (MK) para uso como adición puzolanica en morteros y concretos de cemento Pórtland. El artículo está enfocado en evaluar el desempe o de dos tipos de Metacaolines, cuya materia prima difiere en su composición mineralógica (48 y 97% de caolinita). Se determinó la actividad puzolánica por medio de la norma ASTM C311 y C618 y por el contenido de cal fijada en la reacción de hidratación a través del Análisis Termogravimétrico (ATG). Se evaluaron las propiedades de absorción capilar y la permeabilidad a cloruros en morteros adicionados con el 10 y 20% de MK con respecto a la cantidad de cemento. Los resultados indicaron un mejor comportamiento para las mezclas adicionadas con MK obtenido a partir del Caolín de mayor pureza. Sin embargo, la diferencia entre las propiedades mecánicas y de durabilidad de las mezclas con el 20% de adición de los dos tipos de MK evaluados fue mínima, lo cual indica la posibilidad de utilización de caolines de menor pureza para producir este tipo de puzolana
Características de desempe?o de un concreto adicionado con cenizas volantesde alto nivel de inquemados
Valderrama,Claudia Patricia; Torres Agredo,Janneth; Mejía de Gutiérrez,Ruby;
Ingeniería e Investigación , 2011,
Abstract: engineering today requires that structures are strong and durable; the latter concept is a decisive factor in their design and construction. the scientific community continues developing new cementitious materials and improving traditional concrete′s properties, specifically reducing permeability by incorporating materials such as pozzolans. this paper analyses the effect of fly ash (fa) added to concrete on mechanical strength regarding compression, capillary absorption and chloride permeability and their behaviour compared to concrete containing silica fume (sf). an optimum 10% mechanical strength was found for fly ash; however, this increased with addition, resulting in positive effects on durability. fly ash had lower performance for all properties evaluated when compared to silica fume.
Reutilización de un residuo de la industria petroquímica como adición al cemento portland
Torres Agredo,Janneth; Trochez Serna,Jenny J; Mejía de Gutiérrez,Ruby;
Ingeniería y Ciencia , 2012,
Abstract: in this article the possibility of using waste from the petrochemical industry, as partial replacement of portland cement is studied, evaluating the presence of contaminants in the waste and the encapsulation, once it is confined on the cement. this has been done, in order to find a use to this residue without cause damage to the environment. this residue, called spent fluid catalytic cracking catalyst (fcc), is mainly formed by a type y zeolite, which is dispersing in an inorganic oxides matrix. the toxicity characteristic leaching proceeding was applied, in mortars adding with 20% of fcc as portland cement replacement. the results showed that the residue does not represent a problem from the point of view of the leaching of elements, such as as, pb, zn, cr, and la, which were below to the permissible limits. additionally, the pozzolanic activity of fcc was evaluated according to astm c311, where the efficiency of the residue as pozzolanic addition is demonstrated. with the results the importance of reusing a residue of the petrochemical industry is emphasized, that decreases the amount of cement to be used and improves the mechanical resistance of the materials containing it.
Efecto del porcentaje de adición de metacaolín en las propiedades finales del concreto adicionado
Torres-Agredo,Janneth; Mejía-de-Gutiérrez,Ruby; Delvasto-Arjona,Silvio;
Ingeniería y Universidad , 2011,
Abstract: the present paper is part of a research project whose main objective was to obtain metakaolin (mk) from raw materials obtained in colombia. mk is to be used as a pozzolan in portland cement manufacturing. in previous studies, the performance shown by concrete blended with mk, in terms of mechanical strengths and durability, proved to be adequate. as a result, the effect of the percentage of added mk on the properties of concrete was studied. for purposes of comparison, mk was substituted with silica fume (sf). compressive strength and durability tests, such as total absorption, capillary absorption, and chloride permeability, were used. for compressive strength, concrete showed better performance when mixed up with a 20% mk. higher mk percentages generated a decrease in resistance. additionally, when compared to concrete mixed with sf, compressive strength was slightly lower for mk-mixed concrete. nevertheless, mk proved to be better in terms of durability with respect to the pattern sample and the one added with sf.
CORROSION BEHAVIOR OF STEEL BAR EMBEDDED IN ALKALI-ACTIVATED SLAG CONCRETE SUBJECTED TO CARBONATION AND CHLORIDE ATTACK
APERADOR CHAPARRO,WILLIAN; VERA LóPEZ,ENRIQUE; MEJíA DE GUTIéRREZ,RUBY;
DYNA , 2012,
Abstract: this paper presents an experimental study on the corrosion resistance of a steel bar embedded in an alkali-activated slag (aas) concrete in which it was exposed to an accelerated carbonation test (3% co2, 65% relative humidity (rh), and 25 oc) and then tested under complete immersion in 3.5 wt. % nacl solution. ordinary portland cement (opc) was also tested for comparative purposes and was exposed to identical experimental conditions. the monitoring of open-circuit potential, the linear polarization resistance technique, and the electrochemical impedance spectroscopy (eis), were used to evaluate the corrosion behavior of the steel bar. corrosion resistance of carbonated aas and opc concretes was tested at different times. we carried out an exposure test of a solution containing cl ions with all series for 0, 3, 6, 9, and 12 months. electrochemical measurements show that aas concrete presents depassivation of the steel embedded in concrete where it is exposed to accelerated carbonation; after this period of time, corrosion resistance decreased due to the presence of chlorides at the steel/aas interface.
Concreto adicionado con metacaolín: Comportamiento a carbonatación y cloruros
Mejía de Gutiérrez,Ruby; Rodríguez,Cesar; Rodríguez,Erich; Torres,Janneth; Delvasto,Silvio;
Revista Facultad de Ingeniería Universidad de Antioquia , 2009,
Abstract: the purpose of this paper is to present the results obtained in an experimental study that analyzed the performance of different concrete mixes. these mixes were produced with 90% of ordinary portland cement (opc) and the other 10% with the additions of metakaolin (mk) and silica fume (sf). four types of mk were tested; two of these were produced by a thermal treatment on colombian kaolin. the others two were imported from the international commercial market. the factors evaluated in all the concrete mixes were the following: compressive strength, water absorption and total volume of permeable porosity, capillary absorption, carbonation depth and chloride penetration. the concrete samples were submitted into an accelerated carbonation process inside a climatic chamber (30o c, 70% h.r. and 2.25% co2). at 28 days of curing the carbonation depths for the blended concrete mixtures were greater than the one obtained in the opc concrete without addition. with a prolonged curing age in all samples, with or without mineral additions, tend to slow the carbonation rate in the concrete. the resistance of the concrete to the chloride penetration was evaluated according to astm standard c1202. this study proved that blended concrete specimens have a lower capillary absorption and a higher chloride penetration resistance once these were compared with opc concrete specimens without addition.
Proceso de hidratación de pastas de OPC adicionadas con caolín tratado térmicamente
Torres,Janneth; de Gutiérrez,Ruby Mejía; Castelló,Ricardo; Vizcayno,Carmen;
Revista Facultad de Ingeniería Universidad de Antioquia , 2008,
Abstract: the results obtained in an experimental study that analyzed the hydration process of ordinary portland cement (opc) paste with 20% addition of thermally treated kaolin (ttk) are presented. the kaolin was thermally treated between 500 and 900°c. resulting pastes were analyzed by x-ray diffraction (xrd), differential thermogravimetry (dtg) and scanning electronic microscopy (sem). after 60 curing days the main phases present in the ttk-cement system were the csh gel, gehlenite hydrated amorphous (c2ash8) and portlandite (ch). the kaolin treatment temperature affects the hydrated system phase composition.
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