Incremento del Efecto Plastificante del Bioproducto MEF-32 en Pastas de Cemento P-35
Fecha
2014-07-01
Autores
Rodríguez León, Julio Pastor
Título de la revista
ISSN de la revista
Título del volumen
Editor
Universidad Central "Marta Abreu" de las Villas
Resumen
Se determinó la influencia de las modificaciones tanto en el proceso de obtención (incremento de MP), como el aumento del pH de los bioproductos MEF, en el incremento de su efecto plastificante. Se realizó el análisis químico al MEF-32, y se evidenció que este presenta características químico-física similares a la referencia MEF-19 y a través de su espectro FTIR se encontraron la presencia de varios grupos funcionales, reafirmando la complejidad química de estos bioproductos. Se comprobó que tanto las modificaciones en el pH, como el incremento en las MP en el proceso de producción de los bioproductos, cambiaron sus propiedades químico-físicas tales como la conductividad eléctrica (C.E), sólidos totales disueltos (T.D.S) y sólidos solubles (S.S). Mediante el ensayo del minicono se estableció la influencia de estas modificaciones en el bioproducto MEF sobre el índice de plasticidad y como resultado se obtuvo que existe diferencias entre el MEF-32 y su referencia MEF-19, pero mantienen la misma tendencia, de que a mayor dosis empleada, mayor índice de plasticidad fue logrado. Por otro lado, el MEF-32 a pH 7, fue el que presentó mejor IP en cuanto a las modificaciones de pH y los MEF tipo-3 y MEF tipo-6 en cuanto a las modificaciones del proceso productivo. También se corroboró que el ácido acético y su sal acetato de sodio a las concentraciones y dosis ensayadas, presentan influencia sobre la plasticidad de las pastas de cemento P-35. De igual manera, se evaluaron mezclas de ácido láctico con ácido acético y la mezcla correspondiente a la mayor concentración de ácido láctico y la menor de ácido acético, fue la que presento IP. A través de la calorimetría isotérmica, se determinó como influían estas modificaciones en la cinética de hidratación del cemento, presentando como resultado que estas influyen sobre el calor de hidratación. Los ensayos reológicos realizados a los productos modificados en cuanto a pH, no afectaron la consistencia normal y los tiempos de fraguado de las pastas de cemento P-35 determinados en el ensayo de la Aguja de Vicat.
The influence of variations in both the process of obtainment (increased MP), as increasing pH of the MEF bioproducts in increasing its plasticizing effect was determined. Chemical analysis to MEF-32 was performed, and it was evident that this presents chemical-physical similar to the reference MEF-19 and through its FTIR spectrum the presence of several functional groups were found, confirming the chemical complexity of these bioproducts. It was found that both the changes in pH, as the increase in MP in the process of production of bioproducts, changed their chemical and physical properties such as total soluble electrical conductivity (EC), dissolved solids (TDS) and soluble solids (SS). By mini-slump test, the influence of these modifications was established in bioproduct MEF on the plasticity index and as a result was obtained that there are differences between MEF-32 and MEF-19 reference, but maintain the same trend, which highest dose used, the greater plasticity index was achieved. On the other hand, MEF-32 at pH 7, was the best presented as IP changes to pH and type MEF and MEF-3 type-6 for the changes in the production process. Also, it was confirmed that the acetic acid and sodium acetate at doses and concentrations tested, had influence on the plasticity of P-35 cement pastes. Similarly, mixtures of lactic acid and acetic acid corresponding to the highest concentration of lactic acid and lower acetic acid mixture was evaluated, it was presenting the better IP. Through isothermal calorimetry, was determined as influenced these changes on the kinetics of cement hydration as a result showing that these influence over the heat of hydration. Rheological tests performed on products modified as to pH, did not affect the normal consistency and setting times of P-35 cement pastes determined with Vicat Needle test.
The influence of variations in both the process of obtainment (increased MP), as increasing pH of the MEF bioproducts in increasing its plasticizing effect was determined. Chemical analysis to MEF-32 was performed, and it was evident that this presents chemical-physical similar to the reference MEF-19 and through its FTIR spectrum the presence of several functional groups were found, confirming the chemical complexity of these bioproducts. It was found that both the changes in pH, as the increase in MP in the process of production of bioproducts, changed their chemical and physical properties such as total soluble electrical conductivity (EC), dissolved solids (TDS) and soluble solids (SS). By mini-slump test, the influence of these modifications was established in bioproduct MEF on the plasticity index and as a result was obtained that there are differences between MEF-32 and MEF-19 reference, but maintain the same trend, which highest dose used, the greater plasticity index was achieved. On the other hand, MEF-32 at pH 7, was the best presented as IP changes to pH and type MEF and MEF-3 type-6 for the changes in the production process. Also, it was confirmed that the acetic acid and sodium acetate at doses and concentrations tested, had influence on the plasticity of P-35 cement pastes. Similarly, mixtures of lactic acid and acetic acid corresponding to the highest concentration of lactic acid and lower acetic acid mixture was evaluated, it was presenting the better IP. Through isothermal calorimetry, was determined as influenced these changes on the kinetics of cement hydration as a result showing that these influence over the heat of hydration. Rheological tests performed on products modified as to pH, did not affect the normal consistency and setting times of P-35 cement pastes determined with Vicat Needle test.
Descripción
Palabras clave
Bioproducto MEF-32, Pastas de Cemento P-35, Efecto Plastificante, Propiedades Químico -Físicas, Ensayo de la Aguja de Vicat.