CARACTERIZACIÓN DE LA CAPACIDAD DE ABSORCIÓN DE ENERGÍA DE HORMIGONES REFORZADOS CON FIBRAS

Abstract

metálicas, para el primer caso se utilizará fibra Barchip 54 en cantidades de 4, 8 y 12 kg/m³ y en segundo lugar se utilizarán fibras Dramix 3D 65/36 BG cuya dosificación presenta 25 y 40 kg/m³. Estos datos nos permitirán comparar el comportamiento que tiene el hormigón para distintas dosificaciones y distintos tipos de fibra.Los resultados de estos ensayos nos permitirán ver un aumento de la capacidad de absorción de energía del hormigón a medida que se aumenta la cantidad de fibra por metro cúbico, además de establecer curvas de tendencia, con las cuales se podrá estimar la cantidad de fibra necesaria para alcanzar un nivel de energía de acuerdo a la condición del terreno.Por último se observará un distinto desempeño de acuerdo a la cuantía de fibra utilizada, donde al utilizar una baja dosificación, las fibras sintéticas presentan mejores resultados, no así para grandes cuantías, donde la fibra metálica presenta una mayor cantidad de energía absorbida.The Fibers as reinforcement are commonly used in tunnel construction, since their addition in shotcrete allow to replace the welded meshes, achieving reductions in costs and time.For this reason, concrete must check its structural capacity, through the static test of panel rupture, which is realized under the EFNARC 1996 recommendation and the Spanish standard UNE EN-14488-5. This test simulates the behavior of the concrete cladding under the rock pressure around an anchor bolt, giving as a result a displacement load curve with which the absorbed energy will be calculated. This energy will allow us to determine the degree of resistance of the concrete, indicating for which types of terrain it is suitable.This research will characterize the performance of concrete reinforced with synthetic and metallic fibers. For the first case, Barchip 54 fiber will be used in quantities of 4, 8 and 12 kg/m³, and secondly Dramix 3D 65/36 BG fibers will be used in dosages of 25 and 40 kg/m³. These data allow us to compare the behavior of concrete for different dosages and different types of fiber.The results of these tests will allow us to see an increase in the energy absorption capacity of the concrete as the amount of fiber per cubic meter is increased, in addition to establishing trend curves, with which it will be possible to estimate the amount of fiber needed to reach an energy level according to the condition of the terrain.Finally, a different performance will be observed according to the amount of fiber used, where using a low dosage, the synthetic fibers present better results, but not for large amounts, where the metallic fiber presents a greater amount of energy absorbed.