Thesis CARACTERIZACION DE PROPIEDADES DE HORMIGONES CON FIBRAS SINTETICAS MODIFICADOS CON POLIMEROS
Loading...
Date
2016
Authors
LARA ALFARO, ANDRÉS VALENTINO
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
En los últimos años, la irrupción en el mercado nacional de las fibras sintéticas estructuralespara el refuerzo del hormigón ha provocado cambios significativos en las faenas de construcción detúneles, especialmente en la minería, donde se han reemplazado los shotcrete reforzados con mallasde acero por shotcrete reforzados con estas fibras. Este reemplazo obliga al uso de hormigones dealta fluidez y con mayores contenidos de finos, para compensar la presencia de las fibras, las que seconsideran como un agregado con un bajo coeficiente volumétrico. Esto se logra con laincorporación de polímeros que mejoran la trabajabilidad, disminuyen las perdidas por rebote,incrementan la resistencia a la compresión y disminuyen la permeabilidad, logrando una mayordurabilidad del sostenimientos de túneles.Considerando lo anterior, el objetivo de esta memoria es determinar el efecto que produce eladitivo polimérico ETONIS 850 en las propiedades de mezclas diseñadas para ser utilizadas como“shotcrete” reforzados con fibras sintéticas.Para lograr el objetivo propuesto, se elaboraran tres dosificaciones de iguales características,reforzadas con 6 kg/m3 de fibras sintéticas estructurales tipo Barchip 54, las que serán modificadascon diferentes cantidades del aditivo polimérico en estudio.El efecto del aditivo se evaluara a través de la resistencia a la compresión, el módulo deelasticidad y la capacidad de absorción de energía de los hormigones reforzados con fibrasestudiados, las que serán contrastadas con los resultados obtenidos con una mezcla patrón sinaditivo.
In recent years the outbreak of the recent crisis of the national reinforcement synthetic fibershas made significant changes for the tunnel construction work, especially in the mines where it’sbeen replaced the shotcrete reinforce with steel meshes for shotcrete with synthetic fibers. Thisreplacement forces us to use the concrete with very high fluidity levels and with higher contents offine soils to compensate the presence of fibers, which are considered as an adjunct with lowvolumetric coefficient. This is done by incorporating polymers to improve workability, decrease therebound effect, increase compressive strength resistance and decrease the permeability, to improvedurability tunnel roof supports.With that said, the objective of this report is to determine the effect produced by thepolymeric additive Etonis 850 in the properties of mixtures designed to be used as shotcretereinforced with synthetic fibers.In order to achieve the objectives, three dosages of the same characteristics are developedand reinforced with 6 kg/m3 of synthetic fibers structural type Barchip 54, which are modified withdifferent amounts of polymer additive.The polymer effect is been evaluated by the compressive strength resistance, elasticmodulus and its capacity to absorb the energy from concrete reinforced with synthetic fibers, tofinally be compared with the results obtained with a standard mixture without additive.
In recent years the outbreak of the recent crisis of the national reinforcement synthetic fibershas made significant changes for the tunnel construction work, especially in the mines where it’sbeen replaced the shotcrete reinforce with steel meshes for shotcrete with synthetic fibers. Thisreplacement forces us to use the concrete with very high fluidity levels and with higher contents offine soils to compensate the presence of fibers, which are considered as an adjunct with lowvolumetric coefficient. This is done by incorporating polymers to improve workability, decrease therebound effect, increase compressive strength resistance and decrease the permeability, to improvedurability tunnel roof supports.With that said, the objective of this report is to determine the effect produced by thepolymeric additive Etonis 850 in the properties of mixtures designed to be used as shotcretereinforced with synthetic fibers.In order to achieve the objectives, three dosages of the same characteristics are developedand reinforced with 6 kg/m3 of synthetic fibers structural type Barchip 54, which are modified withdifferent amounts of polymer additive.The polymer effect is been evaluated by the compressive strength resistance, elasticmodulus and its capacity to absorb the energy from concrete reinforced with synthetic fibers, tofinally be compared with the results obtained with a standard mixture without additive.
Description
Catalogado desde la version PDF de la tesis.
Keywords
ADITIVO POLIMERICO , FIBRAS SINTETICAS ESTRUCTURALES , SHOTCRETE REFORZADOS CON FIBRAS SINTETICAS.