Name: concrete fatigue under repeated loads
Uploaded: 2024-11-07T14:48:31.000Z
Duration: 1 min 22 s
Channel: JoVE

En el hormigón, la fatiga puede provocar dos formas distintas de fallo. La primera se produce bajo una carga constante o que aumenta gradualmente; Esto se conoce como fatiga estática o ruptura por fluencia.
La segunda forma de falla ocurre bajo cargas cíclicas o repetidas, llamada fatiga cíclica.
La resistencia a la compresión generalmente se mide en un lapso corto de 2 a 4 minutos. A medida que la tasa de carga disminuye o la duración de la prueba aumenta, la resistencia medida cae por debajo de la observada en las pruebas estándar.
Por el contrario, si la carga se aplica rápidamente o casi instantáneamente, la resistencia resultante es mayor, pero la deformación del material en caso de falla, o capacidad de deformación, se reduce.
A bajas tasas de carga, la fatiga estática en el concreto ocurre cuando la tensión supera aproximadamente el 70 al 80 por ciento de la resistencia a corto plazo. Este nivel marca el comienzo de la rápida formación de microfisuras, lo que conduce a la falla.
El hormigón se vuelve más fuerte a medida que envejece, y su capacidad para soportar cargas repetidas, o resistencia a la fatiga, aumenta proporcionalmente. Esto significa que el hormigón falla bajo fatiga a niveles de tensión proporcionales a la resistencia máxima, independientemente de la edad.

resistencia a la fatiga del hormigón

Fatigue Strength of Concrete

La fatiga, en el contexto de la ciencia y la ingeniería de materiales, se refiere al debilitamiento o falla de un material causado por cargas aplicadas repetidamente, incluso si estas cargas están por debajo del límite de resistencia del material. La resistencia a la fatiga en el hormigón es una propiedad crítica que influye en su durabilidad y longevidad. El hormigón puede fallar de dos formas debido a la fatiga. La fatiga estática o rotura por fluencia ocurre bajo una carga constante o una que aumenta lentamente. El otro modo de falla se debe a cargas cíclicas o repetidas, conocidas como fatiga.

Curiosamente, la resistencia a la compresión del hormigón, que normalmente se mide en un breve lapso de unos pocos minutos, varía con la velocidad a la que se aplica la carga y la duración de la prueba; por ejemplo, una velocidad de carga más lenta o una duración de prueba más prolongada dan como resultado una resistencia medida más baja. Al mismo tiempo, la aplicación rápida de la carga mejora la resistencia, pero reduce la capacidad de deformación del material. La fatiga estática surge a bajas velocidades de carga cuando el esfuerzo supera aproximadamente el 70 u 80 por ciento de la resistencia a corto plazo, lo que inicia la formación rápida de microfisuras y conduce a la falla. A medida que el hormigón envejece, su resistencia y resistencia a la fatiga aumentan a la vez, lo que indica que la falla por fatiga se produce en un porcentaje constante de su resistencia máxima, independientemente del número de ciclos.

Resistencia a la fatiga del hormigón

En el hormigón, la fatiga puede provocar dos formas distintas de fallo. La primera se produce bajo una carga constante o que aumenta gradualmente; A esto se le conoce ...

Education

Educación

JoVE Core

Civil Engineering

Ingeniería Civil

Unit 1

Unidad 1

Strength of Concrete

Resistencia del hormigón

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

concrete fatigue under repeated loads

Concrete fatigue describes how concrete can weaken or fail when loads are applied again and again, even when each load is below the material’s strength limit. This property matters because it affects the durability and service life of concrete structures. In materials science and engineering, fatigue is a key reason concrete may not last as long as expected under real use.

Concrete can fail in two main ways through fatigue. Static fatigue, also called creep rupture, happens under a constant load or a load that rises slowly. The other type comes from cyclical or repeated loading, which is simply called fatigue.

The measured compressive strength of concrete depends on how fast the load is applied and how long the test lasts. A slower loading rate or a longer test time gives a lower strength value. A rapid load can increase the measured strength, but it also reduces the strain capacity of the material.

Static fatigue usually begins when stress is above about 70 to 80 percent of the short-term strength. At this level, microcracks form quickly and can lead to failure. As concrete ages, both its strength and its fatigue strength increase together. This shows that fatigue failure tends to occur at a consistent percentage of the maximum strength, no matter how many loading cycles are involved.

Concrete Fatigue Under Repeated Loads

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tensile-strength-considerations-of-concrete

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behavior-of-concrete-under-compressive-load

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aggregate cement ratio

How Mix Ratio Changes Concrete Strength

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fatigue strength of concrete

Concrete fatigue describes how concrete can weaken or fail when loads are applied again and again, even when each load is below the material’s strength limit. This property matters because it affects the durability and service life of concrete structures. In materials science and engineering, fatigue is a key reason concrete may not last as long as expected under real use. Concrete can fail in two main ways through fatigue. Static fatigue, also called creep rupture, happens under a constant...

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key terms and concepts

Learn how concrete can fail under constant or repeated loads, why loading rate changes measured strength, and how aging affects fatigue strength.

Concrete Fatigue Under Repeated Loads | JoVE K12

JoVE Core Civil Engineering provides a foundational exploration of essential construction materials in civil engineering, focusing on bricks, stones, steel, wood, and concrete through easy-to-understand animated videos. This collection covers the properties, manufacturing processes, and practical applications of these materials. Additionally, the accompanied science-in-action videos demonstrate the research experiments performed in laboratories.

civil engineering

Concrete Fatigue Under Repeated Loads

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