Resistencia final en hormigones con retardo de fraguado
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Fecha
2018
Profesor/a Guía
Facultad/escuela
Idioma
es
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Título del volumen
Editor
Universidad Andrés Bello
Nombre de Curso
Licencia CC
Licencia CC
Resumen
La incorporación de aditivos reductores de agua al diseño de mezclas y aditivos controladores de hidratación logran mejorar el desempeño del hormigón fresco y endurecido mejorando su docilidad y trabajabilidad, además de mejorar su desempeño de resistencia final al optimizar la razón de agua cemento de la mezcla, todo esto empleando dosis recomendadas que generan un tiempo controlado de fraguado más extenso que el habitual, sin embargo debido a condiciones climáticas extremas o una deficiente medición del aditivo se pueden generar retardos de fraguados no controlados. En este informe se realizarán retardos inducidos a diversas mezclas a través del empleo de un aditivo controlador de hidratación, en este caso “Master Delvo”, el cual extenderá los tiempos de trabajo y fraguado del hormigón que contiene cemento puzolanico grado corriente, en comparación a una mezcla tipo sin aditivo. Sin embargo, existe un punto en el cual la dosis de aditivo que se incorpora según la temperatura genera un impacto no deseado en la mezcla como puede ser un retardo de fraguado prolongado no controlado por ello cobra relevancia conocer este punto de equilibrio y dosis empleada, además en el caso de presentar el defecto de retardo conocer el real impacto que tiene sobre el hormigón en su desempeño de su resistencia final. Para conocer este desempeño se realizan ensayos de aptitud en el hormigón en estado fresco y endurecido, con y sin retardo, se ejecutarán ensayos de medición en el hormigón de temperatura, docilidad y aspecto en el estado fresco,para el estado endurecido se medirán resistencias iniciales y finales considerando empleo de probetas cubicas de arista 20cm x 20cm. En paralelo para conocer el retardo de fraguado se considera la medición tiempos de fraguado para las distintas pastas de cemento considerando la homologación de la razón agua –cemento de los hormigones empleados en el control de resistencias.
The incorporation of water reducing additives to the design of mixtures and hydration control additives manage to improve the performance of fresh and hardened concrete, improving its docility and workability, as well as improving its final resistance performance by optimizing the cement water ratio of the mixture, all this using recommended doses that generate a controlled time of hardening more extensive than usual, however due to extreme climatic conditions or a deficient measurement of the additive can generate delays of uncontrolled setting. In this report induced delays will be made to various mixtures through the use of a hydration controller additive, in this case "Master Delvo", which will extend the working and setting times of concrete containing pozzolanic grade cement, compared to a mixture type without additive. However, there is a point at which the dose of additive that is incorporated according to the temperature generates an undesired impact on the mixture, such as a prolonged setting delay, which is not controlled, therefore, it becomes relevant to know this equilibrium point and dose used, also in the case of presenting the delay defect know the real impact it has on the concrete in its performance of its final strength. In order to know this performance, aptitude tests in the concrete in fresh and hardened state are carried out, with and without delay, measurement tests will be carried out on the temperature concrete, docility and appearance in the fresh state, for the hardened state, initial resistances will be measured and endings considering the use of cubic samples of edge 20cm x 20cm. In parallel to know the setting delay, the measurement of setting times for the different cement pastes is considered, considering the homologation of the water - cement ratio of the concretes used in the control of resistances.
The incorporation of water reducing additives to the design of mixtures and hydration control additives manage to improve the performance of fresh and hardened concrete, improving its docility and workability, as well as improving its final resistance performance by optimizing the cement water ratio of the mixture, all this using recommended doses that generate a controlled time of hardening more extensive than usual, however due to extreme climatic conditions or a deficient measurement of the additive can generate delays of uncontrolled setting. In this report induced delays will be made to various mixtures through the use of a hydration controller additive, in this case "Master Delvo", which will extend the working and setting times of concrete containing pozzolanic grade cement, compared to a mixture type without additive. However, there is a point at which the dose of additive that is incorporated according to the temperature generates an undesired impact on the mixture, such as a prolonged setting delay, which is not controlled, therefore, it becomes relevant to know this equilibrium point and dose used, also in the case of presenting the delay defect know the real impact it has on the concrete in its performance of its final strength. In order to know this performance, aptitude tests in the concrete in fresh and hardened state are carried out, with and without delay, measurement tests will be carried out on the temperature concrete, docility and appearance in the fresh state, for the hardened state, initial resistances will be measured and endings considering the use of cubic samples of edge 20cm x 20cm. In parallel to know the setting delay, the measurement of setting times for the different cement pastes is considered, considering the homologation of the water - cement ratio of the concretes used in the control of resistances.
Notas
Tesis (Ingeniero Constructor)
Palabras clave
Resistencia de Materiales, Hormigón, Fraguado, Análisis