Non-contact type concrete resistivity testing instrument

Abstract

The invention discloses a non-contact type concrete resistivity testing instrument. The non-contact type concrete resistivity testing instrument is characterized by comprising an inner working core barrel and an outer working core barrel, wherein the inner working core barrel and the outer working core barrel are assembled into a double-shell barrel body structure by adopting bolts; the double-shell barrel body structure is provided with a ring-shaped iron core and a current testing instrument which respectively surrounds opening ends of an upper barrel and a lower barrel of the inner working core barrel and the outer working core barrel, the inner wall of the inner working core barrel and the outer wall of the outer working core barrel; the inner wall of the outer working core barrel is provided with an induction coil which is connected with a voltage testing instrument outside the outer working core barrel by a wire; and the iron core on the outer wall of the outer working core barrel is wound with a primary coil which is connected with a power supply outside the outer working core barrel by a wire. The non-contact type concrete resistivity testing instrument disclosed by the invention is based on the electromagnetic mutual inductance principle, can be used for testing the resistivity when being buried and cast in concrete, and is suitable for monitoring the change of the resistivity of the concrete for a long time and in real time.

Description

technical field [0001] The invention relates to a concrete measuring instrument, in particular to a non-contact concrete resistivity measuring instrument. Background technique [0002] Concrete structure engineering is widely used in ports, railways, national defense, industrial and agricultural production, and life, but its use is restricted by issues such as durability. At present, a wide variety of testing techniques and equipment are used in concrete detection; traditional concrete damage identification methods are difficult to reflect the damage state of in-situ concrete, and non-destructive testing technology is a better way to obtain the real damage of in-situ concrete in structures. Concrete resistivity measurement method is a relatively new non-destructive testing technology, which has the advantages of simple, fast, cost-effective and remote real-time monitoring. It will become a new technology for rapid detection, online monitoring and effective evaluation of conc...

AI Technical Summary

Problems solved by technology

However, there are still some deficiencies in the existing concrete resistivity measurement methods. The main performance is that the traditional detection techniques and methods are not only affected by the detection environment and conditions, but also the results are relatively one-sided due to the randomness of sampling. If the two-electrode method cannot eliminate the influence of contact resistance, the measured resistance is the sum of the resistance of the concrete material, the wire and the measuring instrument, the wire and the electrode, the contact resistance between the electrode and the concrete, and the contact resistance is related to the material and size of the electrode. It cannot be truly equivalent to the resistivity of concrete materials; the four-electrode method can better reduce the influence of contact resistance, but the electrodes are troublesome to make; the resistivity measured by direct current is poor in stability and repeatability, and the conclusion is of low reliability; The measurement is more complicated, and the selection of frequency also affects the resistivity

In contrast, the non-contact method can better eliminate contact resistance, but the use of direct current to measure resistance will produce capacitance and polarization effects, which will cause a large error between the measured value and the actual value; the non-contact method is currently only applicable to the laboratory In the early research of small-volume cement-based material samples, there were very few online analysis applications in actual engineering, and the required equipment was expensive, such as AC impedance spectroscopy, etc.

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