Reinforced concrete structure crack depth detection method and device based on horizontal shear waves

Abstract

The invention belongs to the technical field of nondestructive testing of civil engineering structures, and provides a reinforced concrete structure crack depth detection method and device based on horizontal shear waves. The method comprises the steps: firstly, detecting and obtaining the propagation speed of the horizontal shear waves in concrete in an intact area; secondly, carrying out detecting at the crack to obtain first arrival wave travel time after diffraction at the crack end; and calculating the crack depth by combining the measured wave velocity, the horizontal distance between the sensor and the transmitting end and the first arrival wave travel time after crack diffraction. A receiving end of developed equipment is provided with a plurality of sensors capable of simultaneously receiving a plurality of signals which are transmitted by the same wave source end but pass through different propagation paths, and an average value of crack depth is calculated by utilizing the plurality of signals detected once and is used as an optimal estimation value of once detection; and the accurate nondestructive testing method for the concrete crack depth is developed, and the methodhas important engineering significance for quantitatively evaluating concrete diseases and ensuring the use safety of the structure.

Description

technical field [0001] The invention belongs to the technical field of nondestructive detection of civil engineering structures, and provides a method and a detection device for crack depth detection of reinforced concrete structures based on horizontal shear waves. Background technique [0002] Concrete shrinkage, stress action, alkali-aggregate reaction, and improper maintenance can all lead to concrete cracking, which is a common disease in reinforced concrete structures in service. The development of cracks will accelerate the corrosion of steel bars inside the concrete, resulting in the reduction of structural bearing capacity and durability, and ultimately threaten the safety of the structure. Although the opening of concrete cracks is visible on the concrete surface, the openings are often too small to measure crack depth directly. Although the method of drilling samples at the cracks can accurately measure the crack depth, it will cause a certain degree of damage to...

AI Technical Summary

Problems solved by technology

[0003] Studies have shown that although the existing non-destructive testing methods for the depth of concrete cracks can detect cracks, the detection accuracy is often low, and it is usually impossible to detect when the cracks are deep

The main reason for the limitation of the existing method is that the existing method is based on the diffraction phenomenon of the compression wave at the end of the crack to detect the crack, and the compression wave attenuates quickly when propagating inside the concrete, and the compression wave will occur after diffraction at the end of the crack. Waveform conversion to generate other types of waves further reduces the signal-to-noise ratio of the detected signal

Moreover, the existing methods use a single sensor, which often requires multiple measurements to give a depth estimate, and the detection speed is too slow to achieve real-time detection.

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