Experimentación y simulación numérica de tubos de hormigón con fibras

Abstract

RESUMENEn este artículo se presentan los resultados principales de un estudio experimental y numérico del comportamiento de tubos hormigón reforzado con fibras de acero (THFA). Se fabricaron y ensayaron 18 tubos de 600 mm de diámetro con cuantías de 10, 20 y 40 kg/m 3 de fibras, concluyéndo-se varios aspectos tecnológicos relacionados con la fabricación y el ensayo así como del comportamiento resistente. Por otra parte, se ha desarrollado el modelo numérico MAP que permite la simulación del comportamiento resistente de THFA sometidos al ensayo de aplastamiento. Los resultados han sido satisfactorios para cualquier régimen de carga, permitiendo concluir que el modelo es una herramienta útil para el diseño óptimo de este tipo de tubos. Se concluye que el uso del modelo conduce a una reducción del coste del armado y da un impulso al uso de fibras como elemento de refuerzo en esta tipología estructural Palabras clave: tubos de hormigón, fibras de acero, ensayo de aplastamiento y fisuración. SUMMARYThe results concerning on an experimental and a numerical study related to SFRCP are presented. Eighteen pipes with an internal diameter of 600 mm and fibre dosages of 10, 20 and 40 kg/m 3 were manufactured and tested. Some technological aspects were concluded. Likewise, a numerical parameterized model was implemented. With this model, the simulation of the resistant behaviour of SFRCP can be performed. In this sense, the results experimentally obtained were contrasted with those suggested by means MAP reaching very satisfactory correlations. Taking it into account, it could be said that the numerical model is a useful tool for the optimal design of the SFRCP fibre dosages, avoiding the need of the systematic employment of the test as an indirect design method. Consequently, the use of this model would reduce the overall cost of the pipes and would give fibres a boost as a solution for this structural typology. Keywords INTRODUCCIÓNLos tubos de hormigón armados con armadura tradicional (THA) y los tubos de hormigón con fibras de acero (THFA) son alternativas conocidas y empleadas para el transporte de agua, residuos industriales, saneamiento entre otros (1-4). Para éstos, la adición de fibras conduce a ventajas tanto técnicas, mejorando las propiedades mecánicas del hormigón (5), como económicas (2). Si se emplean además barras de acero, éstas desempeñan la tarea resistente principal (6) mientras que las fibras activan un mecanismo de puente entre los labios de las fisuras que conduce a una reducción de su separación y de su apertura (7). Desde la vertiente económica, el ahorro de armadura tradicional se traduce en una disminución de las operaciones de montaje, mano de obra, maquinaria, así como de los riesgos asociados (2).El uso de fibras para el refuerzo de tubos de hormigón (TH) no es reciente, sino que su desarrollo se inició hace prácticamente dos décadas. No obstante, su introducción en el mercado está siendo progresiva a causa de factores como riesgo de cortes durante las tareas de manipulación, falta y/o desconoc...

Flexural Performance of a New Hybrid Basalt-Polypropylene Fiber-Reinforced Concrete Oriented to Concrete Pipelines

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