scholarly journals Studies on Characteristics of Fracture Mechanics of Fiber Reinforced Concrete

1994 ◽  
Vol 5 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Kiyoshi Murakami ◽  
Toshio Urano ◽  
Yoshiyuki Mitsui ◽  
Terumi Nishizawa

The study of fracture mechanics was very much essential because it gives clear idea of arising and propagation of cracks, cause for failure, life of structure, etc. The main aim of this research was to study the fracture behavior of fiber reinforced concrete which was reinforced with polypropylene fiber. The fiber used in concrete with different volume fraction like 0.5%, 0.75% and 1% of total volume of cementitious material. The specimens were prepared with different grades of concrete with different dosage of fiber and then subjected to three point bending test. Using test results the fracture properties like fracture energy, flexural strength; stress intensity factor, fracture toughness and stiffness were found. The experimental results showed that effectiveness of polypropylene fiber for different grades of concrete that is normal, medium and high strength concrete increases with increase in fiber volume and also the fracture properties of fiber reinforced concrete increases with increase in fiber volume and effectiveness of fiber was found for dosage of about 0.75-1% volume


2020 ◽  
Author(s):  
Jacinto Ruiz Carmona ◽  
Juan Rey Rey ◽  
Gonzalo Ruiz López

Este trabajo presenta un modelo para evaluar el comportamiento a flexión de secciones de hormigón reforzado con fibras (FRC). El comportamiento a tracción del hormigón con fibras se representa mediante un modelo cohesivo a través de la ley de ablandamiento lineal incluida en el Código Modelo-2010. Como ecuación de compatibilidad se hace uso de la hipótesis de fisura plana, es decir, se asume que las caras de la fisura permanecen planas durante todo el proceso de fractura, hipótesis que ha sido contrastada recientemente mediante correlación digital de imágenes [1]. El comportamiento a compresión del hormigón se representa a través de un modelo elástico, usando la hipótesis de Navier. La apertura de fisura se evalúa a partir del momento aplicado en la sección y de la profundidad de la fisura a través de la expresión propuesta por Tada et al. [2]. El modelo reproduce el efecto de escala existente en la resistencia a flexotracción (módulo de ruptura) en hormigón y hormigón con fibras. Asimismo se define un número de fragilidad que permite caracterizar el comportamiento de las secciones tanto de hormigón en masa como FRC. La metodología presentada propone el análisis de secciones de FRC a través de diagramas que representen el momento aplicado frente a la apertura de fisura, en vez de la curvatura. Esta metodología, extensible a hormigón armado, se considera una aproximación más física al análisis de secciones fisuradas y plantea a la hipótesis de fisura plana como ecuación de compatibilidad alternativa a la hipótesis de Navier, que es la normalmente incluida en las normativas. Referencias: [1]        S. Gali, K.V.L. Subramaniam. 2018. Multi-linear stress-crack separation relationship for steel fiber reinforced concrete: Analytical framework and experimental evaluation, Theoretical and Applied Fracture Mechanics, 93, 33-43 [2]        Tada, H. et al. 1973. The stress analysis of cracks handbook. Del Research Corporation


2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


PCI Journal ◽  
2012 ◽  
Vol 57 (3) ◽  
pp. 33-46 ◽  
Author(s):  
Nemkumar Banthia ◽  
Vivek Bindiganavile ◽  
John Jones ◽  
Jeff Novak

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