Steel shell-concrete stripping detection device

Abstract

The invention discloses a steel shell-concrete stripping detection device which comprises a thermal neutron detector, a steel plate and a concrete simulation marking block, wherein the steel plate isarranged above the concrete simulation marking block; a gap of which the size can be adjusted is formed between the steel plate and the concrete simulation marking block; the concrete simulation marking block comprises clamping plates, metal standard plates and organic material standard plates; the metal standard plates and the organic material standard plates are in identical lengths and widths;the metal standard plates and the organic material standard plates are vertically or transversely clamped and overlapped between the clamping plates in an alternative manner; the ratio of the metal standard plates to the organic material standard plates is adjusted according to expected concrete water contents and densities. The principle that the retarding and speed reduction action of fast neutrons is determined by the content of hydrogen atoms in concrete is smartly utilized, the detachable concrete simulation marking block is creatively manufactured, concrete of different water contents israpidly simulated, the manufacturing cycle is short, furthermore the indoor calibration cycle is short, and stripping depths of concrete of different water contents under steel shells can be calibrated.

Description

technical field [0001] The invention relates to the application field of radioisotope technology, in particular to a detection device for the void theorem between two heterogeneous media, steel shell and concrete. Background technique [0002] Large-scale hydropower and subsea tunnel projects often have some steel shell-concrete structures, such as pressure pipes of hydropower generating units, turbine volutes, runner chambers, nuclear power plant nuclear islands and large immersed tubes of subsea tunnels. When these concrete structures with steel plate lining are poured, due to the existence of the steel lining and the dense steel bars inside, the pouring construction is very inconvenient, the vibration is quite difficult, and the concrete is difficult to fill. Therefore, concrete and steel plates Void defects often exist between linings, which affect the safety and durability of structures. [0003] In view of this, it is necessary to use certain detection methods to dete...

AI Technical Summary

Problems solved by technology

[0006] 1. The production cycle of the concrete slab module is long, such as after the pouring is completed, it needs to be placed for more than 28 days, etc., which will affect the calibration cycle

[0007] 2. After the production process and completion of the concrete slab module, the actual water content in the concrete slab module will change due to the influence of the ambient temperature and humidity at that time, resulting in a large deviation between the actual water content in the concrete slab module and the set water content

[0008] 3. A concrete slab module can only correspond to one water content. When the water content of concrete changes, a new concrete slab module needs to be made

In the patent application number 92112969.6, when calibrating the correlation curve between the cavity depth and the thermal neutron count rate, the variation of the void depth caused by the difference in concrete water content is not considered, so the calibration result is inaccurate

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