Andres Salas | Universidad Nacional de Colombia (National University of Colombia) (original) (raw)
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Papers by Andres Salas
Ingenieria Y Competitividad Revista Cientifica Y Tecnologica, 2013
Cement and Concrete Research, Sep 1, 2009
Ingenieria e Investigación
El propósito del presente estudio es el de investigar la posibilidad de producir concretos de alt... more El propósito del presente estudio es el de investigar la posibilidad de producir concretos de alto desempeño (HPC, por sus siglas en inglés) mediante el uso de un material puzolánico de alta reactividad elaborado a partir de ceniza de cascarilla de arroz tratada químicamente (ChRHA, por sus siglas en inglés) y preparada mediante un ataque térmico-químico a la cascarilla de arroz. Esta particular ceniza de cascarilla de arroz consiste de 99% sílice de alta amorfidad, blanca, con mayor actividad puzolánica que el humo de sílice y que la ceniza de cascarilla de arroz preparada únicamente con tratamiento térmico (TRHA, por sus siglas en inglés). Las características físicas, químicas y mineralógicas de las cenizas producidas fueron analizadas. En el presente estudio se evaluó la resistencia a la compresión, la resistencia a la flexión, la absorción de agua, la resistencia a la carbonatación, la carga total que pasa, derivada del ensayo rápido de permeabilidad a cloruros (RCPT, por sus si...
Construction and Building Materials, 2015
ABSTRACT Higher quality recycled concrete aggregates (RCA) were used as coarse aggregates in a co... more ABSTRACT Higher quality recycled concrete aggregates (RCA) were used as coarse aggregates in a concrete mixture. The initial aggregate moisture condition (oven dry, partially saturated, fully saturated) and mixing method (normal, two-stage) were assessed in order to limit the differences between concrete containing RCA and virgin aggregates. Concrete with partially-saturated RCA using two-stage mixing was beneficial for improving the compressive and split tensile strengths. For this material, the mixing method did not affect the concrete free drying shrinkage at any age. Overall, the two-stage mixing method increased the concrete workability and could potentially improve the concrete strength properties, particularly when the RCA is partially saturated.
KSCE Journal of Civil Engineering, 2014
ABSTRACT The main purpose of this research is to investigate the freeze-thaw resistance of concre... more ABSTRACT The main purpose of this research is to investigate the freeze-thaw resistance of concrete incorporating acid-leached rice husk ash. The research has been initiated because of its unique microstructural characteristic: rice husk ash maintains the original cellular structure of rice husk that has large amount of empty space, so it has a potential possibility of reducing the air void spacing factor. The freeze-thaw resistance of concrete using rice husk ash is compared to that using silica fume. The result shows that the freeze-thaw resistance of concrete using acid-leached rice husk ash is slightly less than that of silica fume concrete during 300 freeze-thaw cycles. When freeze-thaw cycles are extended to 600 cycles, freeze-thaw resistance of concrete using acid-leached rice husk ash is equivalent to the concrete using silica fume.
Cement and Concrete Research, 2009
Ingenieria Y Competitividad Revista Cientifica Y Tecnologica, 2013
Cement and Concrete Research, Sep 1, 2009
Ingenieria e Investigación
El propósito del presente estudio es el de investigar la posibilidad de producir concretos de alt... more El propósito del presente estudio es el de investigar la posibilidad de producir concretos de alto desempeño (HPC, por sus siglas en inglés) mediante el uso de un material puzolánico de alta reactividad elaborado a partir de ceniza de cascarilla de arroz tratada químicamente (ChRHA, por sus siglas en inglés) y preparada mediante un ataque térmico-químico a la cascarilla de arroz. Esta particular ceniza de cascarilla de arroz consiste de 99% sílice de alta amorfidad, blanca, con mayor actividad puzolánica que el humo de sílice y que la ceniza de cascarilla de arroz preparada únicamente con tratamiento térmico (TRHA, por sus siglas en inglés). Las características físicas, químicas y mineralógicas de las cenizas producidas fueron analizadas. En el presente estudio se evaluó la resistencia a la compresión, la resistencia a la flexión, la absorción de agua, la resistencia a la carbonatación, la carga total que pasa, derivada del ensayo rápido de permeabilidad a cloruros (RCPT, por sus si...
Construction and Building Materials, 2015
ABSTRACT Higher quality recycled concrete aggregates (RCA) were used as coarse aggregates in a co... more ABSTRACT Higher quality recycled concrete aggregates (RCA) were used as coarse aggregates in a concrete mixture. The initial aggregate moisture condition (oven dry, partially saturated, fully saturated) and mixing method (normal, two-stage) were assessed in order to limit the differences between concrete containing RCA and virgin aggregates. Concrete with partially-saturated RCA using two-stage mixing was beneficial for improving the compressive and split tensile strengths. For this material, the mixing method did not affect the concrete free drying shrinkage at any age. Overall, the two-stage mixing method increased the concrete workability and could potentially improve the concrete strength properties, particularly when the RCA is partially saturated.
KSCE Journal of Civil Engineering, 2014
ABSTRACT The main purpose of this research is to investigate the freeze-thaw resistance of concre... more ABSTRACT The main purpose of this research is to investigate the freeze-thaw resistance of concrete incorporating acid-leached rice husk ash. The research has been initiated because of its unique microstructural characteristic: rice husk ash maintains the original cellular structure of rice husk that has large amount of empty space, so it has a potential possibility of reducing the air void spacing factor. The freeze-thaw resistance of concrete using rice husk ash is compared to that using silica fume. The result shows that the freeze-thaw resistance of concrete using acid-leached rice husk ash is slightly less than that of silica fume concrete during 300 freeze-thaw cycles. When freeze-thaw cycles are extended to 600 cycles, freeze-thaw resistance of concrete using acid-leached rice husk ash is equivalent to the concrete using silica fume.
Cement and Concrete Research, 2009