Concrete self-shrinkage deformation and thermal expansion coefficient measuring device and measuring method

Abstract

The invention discloses a concrete self-contraction deformation and thermal expansion coefficient measuring device and a measuring method. The device comprises: a mold and a lining template, wherein the mold is a square container with an opening in the upper portion, the lining template comprises a lining plate attached to the periphery of the inner wall of the mold and a polytetrafluoroethylene layer arranged on the bottom face of the inner side of the mold, and ducts are formed in the two ends of the mold respectively; a displacement testing system which comprises a data acquisition module,measuring heads, displacement sensors and guide rods, wherein the measuring heads, the displacement sensors and the guide rods are arranged corresponding to the ducts, the measuring heads and the ducts are correspondingly pre-buried at the end of a concrete test piece, one ends of the guide rods are connected with the measuring heads, the other ends of the guide rods are connected with the displacement sensors, and the data acquisition module is connected with the displacement sensors; a temperature control system which comprises a temperature sensor, a temperature control soft body layer anda temperature control module, wherein the temperature sensor is pre-buried in concrete, the temperature control soft body layer is attached to the inner side of the lining template, a plastic film isfurther attached to the inner side of the lining template, and the temperature control module collects and controls the temperature of the temperature control soft body layer in real time.

Description

technical field [0001] The invention relates to the field of civil engineering materials, in particular to a measuring device and method for measuring self-shrinkage deformation and thermal expansion coefficient of concrete. Background technique [0002] Concrete cracking is an unavoidable problem that has not been fundamentally resolved. Modern high-performance concrete requires concrete to have high durability, but the generation of cracks is bound to be detrimental to the durability of concrete. Cracks provide a way for external substances (such as various ions, water, air, etc.) to corrode concrete. These substances will trigger various reactions, accelerate the deterioration of concrete quality and rust the steel bars, and the deterioration of concrete quality will accelerate the above process. Therefore, the cracks Presence greatly reduces the service life of the structure, reducing durability. From the perspective of the mechanical principle of concrete cracks, the ...

AI Technical Summary

Problems solved by technology

[0002] Concrete cracking is a problem that has not been fundamentally solved but cannot be avoided

Existing measuring devices and measuring methods are difficult to achieve

Such as CN101701925A, CN101865865A, CN202066814U, CN101000338A, CN103558246A, CN108181346A, CN108226215A patent disclosed measuring method can only measure the concrete thermal expansion coefficient after hardening, can't measure the thermal expansion coefficient of super-early age fresh concrete since pouring moment

The measurement methods disclosed in CN102608152A and CN103293179A patents make the actual temperature inside the concrete different from the ambient temperature, that is, there is a temperature gradient field inside the concrete, so that the calculated temperature difference is not the real temperature difference, and the measurement method does not peel off the self-shrinkage

But in fact, when the thermal expansion of concrete occurs, it is not about -2 ~ 3 ℃, which is not consistent with the actual situation.

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