A capacitive cement-based humidity sensor and its preparation method

Abstract

The invention discloses a capacitive cement-based humidity sensitive element and a preparing method thereof. The element is composed of a cylindrical cement-based blank and ring-shaped electrodes, wherein the ring-shaped electrodes are located at the positions which are spaced from two end openings of the cylindrical cement-based blank by 10-20 cm and are inwards parallel to the two round faces, the cylindrical cement-based blank and the ring-shaped electrodes are bonded in a sealed mode through copper powder mixed with conductive adhesive, and the ring-shaped electrodes are connected with a wire. The element is good in durability, a certain quality of porous adsorbing materials are doped, the element makes close contact with a building and can synchronously detect the relative humidity in a building structure in time, and measurement results are timely and reliable. Durability of the building structure will not be affected by burying the measuring element, the humidity sensitive element is low in price, and therefore construction cost can be reduced greatly.

Description

technical field [0001] The present invention relates to a relative humidity sensing test element, in particular, relates to a hydration process of cement-based materials (such as cement mortar, concrete, etc.) A capacitive cement-based humidity sensor and a preparation method thereof belong to the field of engineering material detection. Background technique [0002] Under normal conditions, the mechanical properties of cement-based materials such as drying shrinkage, creep and crack formation are closely related to their internal relative humidity conditions; for cement-based materials that have been in a dry and wet environment for a long time, the internal environmental humidity changes It is inseparable from its durability. Therefore, accurate detection of humidity changes inside cement-based materials can provide insight into the health of civil and architectural structures. At present, the commonly used test method is the embedded pipeline method. This method is to e...

AI Technical Summary

Problems solved by technology

Invention patents CN101603937B "Cement-based material internal relative humidity testing device and its testing method" and CN103163285A "a device for measuring relative humidity and temperature inside cement concrete" overcome the above-mentioned shortcomings of traditional pre-buried pipelines, but the above two methods still cannot It is very good to test the internal relative humidity in the early stage of cement pouring. At the same time, the gap between the digital humidity measuring element in the device and the cement-based material is too large, which makes it difficult to synchronize the relative humidity of the space where the two are located.

In addition, civil buildings have different shapes, and there are often multiple parts that need to be measured for humidity. A humidity measurement device can only measure the humidity of a specific part. Measuring device, which will cause the stress of the entire building structure to be greatly reduced, seriously affecting its durability; and the humidity measuring device has a short service life and needs to be replaced during service, and the cost is relatively high, which greatly increases the project cost

Images