Method for testing linear expansion coefficient of cement concrete under temperature and humidity coupling action

Abstract

The invention discloses a method for testing a linear expansion coefficient of cement concrete under temperature and humidity coupling action, belonging to the field of road engineering. The method comprises the following steps of: mounting a vibrating wire type concrete strain meter in the center of a measuring barrel, and injecting pavement concrete into the measuring barrel; mounting the measuring barrel at 1 / 2 thickness of the cement concrete surface layer, and determining the linear expansion coefficient of the cement concrete under the temperature and humidity coupling action through the volume change of the concrete in the measuring barrel in a non-stress state along with the change of the temperature and humidity conditions of the pavement concrete. Compared with the prior art, the method for testing the linear expansion coefficient has the advantages that the accurate and reliable expansion coefficient of the cement concrete under the temperature and humidity coupling action and the deformation rule of the cement concrete along with the change of temperature and humidity conditions of a natural environment can be obtained, and the method has a high popularization and application value.

Description

Technical field [0001] The invention relates to the field of road engineering, in particular to a method for testing the linear expansion coefficient of cement concrete under the coupling effect of temperature and humidity. Background technique [0002] In my country's high-grade highways, cement concrete materials are widely used, but engineering practice shows that the cracking and joint opening of cement concrete pavement are more serious, which reduces the performance of cement concrete pavement. Cement concrete pavement cracks and open joints are the main causes of road muddy, staggered and broken slabs. In the calculation of the reinforcement ratio of the continuously reinforced cement concrete pavement and the joint spacing design of the ordinary cement concrete pavement, the expansion coefficient of the cement concrete adopts the method of consulting the reference value of the specification. Due to the difference in aggregate expansion coefficients, the expansion coeffic...

AI Technical Summary

Problems solved by technology

Due to differences in aggregate expansion coefficients, different cement concrete mix ratios, and differences in cement concrete water-cement ratios, it is impossible to know the difference between the selected reference expansion coefficient value and the actual expansion coefficient, and it is impossible to guarantee the reinforcement calculation and joint spacing design. Accuracy and Reliability of Results

Another important issue is that the volume change of hardened cement concrete materials is the result of the combined effect of ambient temperature and humidity. The existing material expansion coefficient test methods cannot obtain the change law of cement concrete volume parameters under the coupling effect of temperature and humidity.

Therefore, the expansion coefficient of cement concrete materials under actual environmental conditions has not been clarified and verified, and the problem of damage caused by excessive crack opening on cement concrete pavement has also plagued engineers and technicians in our country.

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