Device and method for measuring the decrease rate of concrete thermal conductivity during uniaxial compression

Abstract

The invention discloses a device and method for measuring the decrease rate of concrete thermal conductivity in the process of uniaxial compression. The concrete specimen is placed in a bracket and subjected to compression load, and at the same time, a heating unit and a refrigeration unit establish a temperature difference between two planes of the concrete specimen; the bracket is used It is used to fix the relative position of the concrete specimen and the heating unit, refrigeration unit, thermal insulation material, and heat-conducting silica gel; the concrete specimen is deformed after being compressed, and the insulation material, heat-conducting silica gel, refrigeration unit, and heating unit are extruded to move outward. The surrounding pillars of the bracket are used to determine the moving track of the surrounding materials. The spring plate and spring on the pillars provide an appropriate confining pressure that does not affect the mechanical experiment, so as to ensure that the refrigeration unit and heating unit are attached to the surface of the concrete specimen, and the contact heat is minimized. resistance. When the concrete specimen bears a certain compressive load, the heat flux density of the concrete specimen inside the concrete specimen reaches a steady state, and the temperature in the concrete specimen exhibits a one-dimensional stable distribution.

Description

technical field [0001] The invention relates to a device for measuring the decrease rate of concrete thermal conductivity during uniaxial compression, belonging to the technical field of concrete construction. Background technique [0002] In the field of mass concrete engineering, the heat of hydration of cement, sudden changes in external temperature, and external loads on the structure may cause cracks in concrete. The existence of cracks will lead to a decrease in the thermal conductivity of concrete, which in turn affects the expansion of cracks. Therefore, it is extremely important to understand the influence of concrete cracking on thermal conductivity for thermal-mechanical coupling analysis and to prevent further crack expansion. However, at present, people do not have a quantitative understanding of the variation law of the thermal conductivity of damaged concrete, and there is no experimental device for studying the thermal conductivity of cracked concrete. For t...

AI Technical Summary

Problems solved by technology

Although the transient method has the advantages of high efficiency and convenience, it is not suitable for the present invention because the location and quantity of cracks in the concrete are uncertain during the cracking process.

Images