Coarse aggregate degradation test device and method considering relative humidity and freeze-thaw coupling effect

Abstract

The invention discloses a coarse aggregate degradation test device and method considering relative humidity and freeze-thaw coupling effect. The coarse aggregate degradation test device comprises a pressure chamber system, a temperature control system, a humidity control system, a loading system, a computer and a data acquisition system. The temperature control system comprises a constant-temperature chamber, two mosquito-repellent incense type flow channels, a columnar spiral flow channel and three constant-temperature circulating baths; the constant-temperature chamber is arranged at the peripheries of the pressure chamber system and the loading system in a surrounding manner; the temperature of the constant-temperature chamber, the temperature of the lower mosquito-repellent incense type flow channel at the bottom of the sample, the temperature of the columnar spiral flow channel in the middle of the sample and the temperature of the upper mosquito-repellent incense type flow channel at the top of the sample form a gradually decreasing temperature gradient; and the humidity control system is arranged in the constant-temperature chamber, and the generated humidity gas flows in the sample along the gradually decreasing temperature gradient direction. The method can truly reflect the real action mechanism of the high earth and rockfill dam material in high-altitude and alpine regions, and enhances the credibility of the test result while improving the test precision.

Description

technical field [0001] The invention relates to the technical field of geotechnical tests, in particular to a device and method for a coarse-grained material deterioration test considering relative humidity and freeze-thaw coupling effects. Background technique [0002] Coarse aggregates are widely used in roadbeds, railway gravel ballasts, landfill cushions, nuclear waste storage cushions and earth-rock dam projects. For earth-rock dam projects, when the reservoir is impounded or the climate environment changes, the coarse-grained material will cause performance degradation due to the action of water, specifically manifested as a decrease in strength and an increase in compression, which will affect the safe operation of the dam in severe cases. [0003] Compared with conventional concrete dams, earth-rock dams have been widely used in water conservancy and hydropower construction due to their irreplaceable advantages in technology and economy under complex topographic and ...

AI Technical Summary

Problems solved by technology

[0013] Due to the integral temperature control, the instrument cannot simulate the real one-way freezing method, which does not meet the temperature boundary conditions of the actual working conditions

[0014] The temperature of the upper and lower ends of the sample is the same, and there is no temperature gradient, so the water vapor migration process under freezing cannot be completed, and it is difficult to truly consider the coupling effect of relative humidity and freeze-thaw

[0015] There is a large error in the volume variable measurement during the shearing process, and the thermal expansion and contraction effect of the liquid medium in the pressure chamber caused by the temperature difference between the ambient temperature and the test temperature is difficult to eliminate

Images