Análisis petrográfico como herramienta de evaluación de patologías en el hormigón endurecido : aplicación a daños por carbonatación, fuego y de origen químico
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Fecha
2024
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Idioma
es
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Universidad Andrés Bello
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Licencia CC
Licencia CC
Resumen
El análisis petrográfico es una herramienta fundamental para estudiar rocas y
composición mineralógica a niveles microscópicos. Al considerar el hormigón endurecido
como una roca artificial, se hace posible estudiarlo mediante el uso de microscopia óptica.
El objetivo principal de este trabajo es establecer el uso del análisis petrográfico como
una herramienta de evaluación útil para identificar alteraciones en muestras de hormigón
endurecido afectadas por carbonatación, acción del fuego y daños de origen químico.
Para realizar el análisis petrográfico fue indispensable realizar una exhaustiva revisión
bibliográfica que abordara la viabilidad de esta técnica en el estudio de la microestructura
del hormigón. Dicha revisión incluyó la identificación de los equipos necesarios para llevar
a cabo el análisis, así como los tipos de muestras requeridas y los procedimientos para
su preparación. Además, se investigaron los mecanismos de formación de las patologías
estudiadas, su impacto en las estructuras de hormigón, los síntomas y consecuencias
observables a nivel de microestructura.
Las muestras evaluadas se adaptaron según las exigencias particulares de la evaluación.
Para analizar las alteraciones por carbonatación, se utilizó una probeta preparada un año
antes, lo cual resultó beneficioso para evaluar la patología. Las muestras afectadas por
fuego se sometieron a una simulación en el laboratorio de incendios del IDIEM, U. de
Chile, exponiendo una a un ciclo de 35 minutos alcanzando 847°C, y otra muestra testigo
expuesta a un ciclo de 60 minutos alcanzando 926°C. Además, se recolectaron muestras
con daños de origen químico en la escuela de La Greda, ubicada en Puchuncaví, una
zona con alta contaminación debido a las industrias locales.
A través del apoyo de la escuela de Geología de la Universidad Andrés Bello, se
generaron cortes transparentes de hormigón, adaptados para observar en el microscopio
óptico, y así realizar el análisis petrográfico.
Finalmente, se llevó a cabo el análisis petrográfico, evidenciando que la recolección de
muestras desempeña un papel fundamental en la evaluación de patologías. En el caso
de la carbonatación, las muestras mostraban una penetración baja del frente
carbonatado, debido al limitado tiempo de exposición que tuvieron. Por otro lado, en las
muestras afectadas por incendio y daños químicos, se observaron claramente las
alteraciones generadas por la acción de las patologías. Esto confirma que al estudiar
muestras experimentales con alto o bajo índice de daños o bien, al extraer muestras
representativas de estructuras que presenten signos de deterioro, se podrán evaluar e
identificar afectaciones mediante el uso de microscopía óptica. Esto concluye que el
análisis petrográfico es una herramienta muy útil para la evaluación de patologías en el
hormigón endurecido.
Petrographic analysis is a fundamental tool for studying rocks and mineralogical composition at microscopic levels. By considering hardened concrete as an artificial rock, it becomes possible to study it through the use of optical microscopy. The main objective of this work is to establish the use of petrographic analysis as a useful evaluation tool to identify alterations in hardened concrete samples affected by carbonation, fire action and damage of chemical origin. To carry out the petrographic analysis, it was essential to carry out an exhaustive bibliographic review that addressed the viability of this technique in the study of the microstructure of concrete. This review included the identification of the equipment necessary to carry out the analysis, as well as the types of samples required and the procedures for their preparation. In addition, the formation mechanisms of the studied pathologies, their impact on concrete structures, symptoms and consequences observable at the microstructure level were investigated. The samples evaluated were adapted according to the particular demands of the evaluation. To analyze alterations due to carbonation, a test tube prepared a year earlier was used, which was beneficial to evaluate the pathology. The sample affected by fire was subjected to a simulation in the fire laboratory of the IDIEM, University of Chile, exposing it to a 35-minute cycle reaching 847°C, and another control sample exposed to a 60-minute cycle reaching 926°C. In addition, samples with chemical damage were collected at the La Greda school, located in Puchuncaví, an area with high contamination due to local industries. Through the support of the School of Geology of the Andrés Bello University, transparent concrete sections were generated, adapted to be observed in the optical microscope, and thus perform petrographic analysis. Finally, petrographic analysis was carried out, showing that sample collection plays a fundamental role in the evaluation of pathologies. In the case of carbonation, the samples showed a low penetration of the carbonate front, due to the limited exposure time they had. On the other hand, in the samples affected by fire and chemical damage, the alterations generated by the action of the pathologies were clearly observed. This confirms that by studying experimental samples with a high or low damage index or by extracting representative samples of structures that show signs of deterioration, damage can be evaluated and identified through the use of optical microscopy. This concludes that petrographic analysis is a very useful tool for the evaluation of pathologies in hardened concrete.
Petrographic analysis is a fundamental tool for studying rocks and mineralogical composition at microscopic levels. By considering hardened concrete as an artificial rock, it becomes possible to study it through the use of optical microscopy. The main objective of this work is to establish the use of petrographic analysis as a useful evaluation tool to identify alterations in hardened concrete samples affected by carbonation, fire action and damage of chemical origin. To carry out the petrographic analysis, it was essential to carry out an exhaustive bibliographic review that addressed the viability of this technique in the study of the microstructure of concrete. This review included the identification of the equipment necessary to carry out the analysis, as well as the types of samples required and the procedures for their preparation. In addition, the formation mechanisms of the studied pathologies, their impact on concrete structures, symptoms and consequences observable at the microstructure level were investigated. The samples evaluated were adapted according to the particular demands of the evaluation. To analyze alterations due to carbonation, a test tube prepared a year earlier was used, which was beneficial to evaluate the pathology. The sample affected by fire was subjected to a simulation in the fire laboratory of the IDIEM, University of Chile, exposing it to a 35-minute cycle reaching 847°C, and another control sample exposed to a 60-minute cycle reaching 926°C. In addition, samples with chemical damage were collected at the La Greda school, located in Puchuncaví, an area with high contamination due to local industries. Through the support of the School of Geology of the Andrés Bello University, transparent concrete sections were generated, adapted to be observed in the optical microscope, and thus perform petrographic analysis. Finally, petrographic analysis was carried out, showing that sample collection plays a fundamental role in the evaluation of pathologies. In the case of carbonation, the samples showed a low penetration of the carbonate front, due to the limited exposure time they had. On the other hand, in the samples affected by fire and chemical damage, the alterations generated by the action of the pathologies were clearly observed. This confirms that by studying experimental samples with a high or low damage index or by extracting representative samples of structures that show signs of deterioration, damage can be evaluated and identified through the use of optical microscopy. This concludes that petrographic analysis is a very useful tool for the evaluation of pathologies in hardened concrete.
Notas
Memoria (Ingeniero Civil)
Palabras clave
Análisis Petrográfico, Hormigón, Inspección, Innovaciones Tecnológicas