Reinforced concrete structure fatigue test method and device based on piezomagnetic effect

Abstract

The invention relates to the field of research on basic performance of reinforced concrete structures in civil engineering, in particular to a reinforced concrete structure fatigue test method and device based on a piezomagnetic effect. The crack initiation and propagation stage can be clearly defined by testing the magnetic field intensity of a reinforced concrete structure, the fatigue damage process, especially the later rapid degradation process can be grasped, and the fatigue damage form of the structure can be estimated.

Description

technical field [0001] The invention relates to the field of basic performance research of reinforced concrete structures in civil engineering, in particular to a method and device for fatigue testing of reinforced concrete structures based on piezomagnetic effect. Background technique [0002] Fatigue problems exist in the field of civil engineering such as high-rise buildings, long-span space structures, bridges, sleepers, crane beams, airport runways, offshore platforms, and nuclear reactor containment shells, especially with the application of high-strength concrete and high-strength steel bars. The fatigue of concrete structures is increasingly critical to their safety and durability. The fatigue damage of reinforced concrete structures accumulates continuously during the service process, and when a certain limit is reached, sudden brittle failures will occur without obvious warning, which is likely to cause heavy losses. [0003] Due to the complex system of reinforce...

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Problems solved by technology

The fatigue damage of reinforced concrete structures accumulates continuously during the service process, and when a certain limit is reached, sudden brittle failures will occur without obvious warning, which is likely to cause heavy losses

[0003] Due to the complex system of reinforced concrete structures, its fatigue research requires a large number of test supports, and fatigue is affected by factors such as load, material composition and environment, and the damage process is very complicated. The macroscopic physical quantities measured by traditional testing methods such as strain, deflection, stiffness, Cracks cannot effectively reflect the fatigue damage process. At the same time, the fatigue damage mechanism of reinforced concrete structures has not been well resolved, and there is no effective method for monitoring the fatigue damage state of reinforced concrete structures: (1) early fatigue, Due to the absence of obvious changes in micro- and macro-physical quantities, conventional methods are difficult to use, and the stages of crack initiation and crack growth cannot be clearly defined; (2) Fatigue process analysis based on traditional stress-strain hysteretic curves cannot reveal fatigue damage from a microscopic perspective On the other hand, the hysteretic curve is monotonous, and it is difficult to grasp the evolution process of fatigue damage, especially the process of rapid deterioration in the later stage; (3) Under the action of reciprocating loads, the stress state of reinforced concrete structures is very complicated, and the strain, stiffness, crack width, etc. It is also difficult to reveal its microscopic fatigue damage mechanism; (4) Most of the life prediction methods of reinforced concrete structures at this stage are based on their own experiments, and there is no theoretical basis for predicting fatigue life. (5) Existing technologies cannot Prediction of Failure Modes of Reinforced Concrete Beams

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