A method for predicting the impact range of surface cracks on the internal temperature field of concrete

Abstract

The invention discloses a method for predicting the influence range of surface cracks on the internal temperature field of concrete. On the basis of temperature response tests, ANSYS finite element software is used to carry out numerical simulation analysis of concrete temperature response, and a finite element model of concrete specimens with surface cracks is established. , study the one-dimensional temperature response process of the model, consider the thickness of the actual concrete structure protective layer and the crack situation, extract the temperature of the nodes at different depths from the upper surface of the concrete for analysis, and obtain the temperature response equilibrium time of the concrete with surface cracks, and take the distance from the far end of the crack The temperature response equilibrium time at the position is used as the reference quantity, and the ratio of the temperature response equilibrium time at different coordinate positions to this reference quantity is calculated, so as to obtain the relative value of the concrete temperature response equilibrium time at different coordinate positions, and define the corresponding coordinates within a certain relative value The area is the influence range of cracks, and the calculation model of the influence range of concrete cracks is obtained through regression fitting analysis.

Description

technical field [0001] The invention relates to the field of concrete heat transfer, in particular to a method for predicting the influence range of surface cracks on the internal temperature field of concrete. Background technique [0002] The internal temperature field of concrete has an important influence on the durability of concrete structures. Durability problems such as concrete carbonation, chloride ion erosion, and steel bar corrosion in concrete are closely related to the internal temperature field of concrete. Most of the existing prediction models for concrete carbonation, chloride ion erosion and steel corrosion rate take into account the natural environment temperature and relative humidity, and the direct factors affecting the above concrete durability should be the internal temperature and water content of the concrete. In the actual concrete structure, the effect of temperature and load will lead to the cracking of the concrete surface, which will cause th...

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Problems solved by technology

[0003] Since the concrete temperature response test process can only study the influence of cracks on the temperature response of specific points inside the concrete, it cannot reflect the influence of cracks on the internal temperature field of concrete

[0004] At present, there have been patents proposing a practical method for measuring the internal temperature of concrete. Chen Zhanlong and Li Shihua of China Gezhouba Group Co., Ltd. have used a telescopic concrete temperature measuring device in the authorized announcement number: CN202372267U "Telescopic Concrete Temperature Measuring Device" , fix the temperature sensor at the end of the telescopic adjustment rod, adjust the length of the telescopic rod according to the needs, and detect the concrete temperature. This method can only realize the temperature measurement of a specific point inside the concrete, and it is difficult to reflect the boundaries such as cracks on the concrete surface. Changes in the temperature field inside the concrete when conditions change

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