Device and method for testing material creep under coupling action of tensile stress and environment

Abstract

The invention discloses a device for testing material creep under the coupling action of tensile stress and the environment. The device comprises a support, a weight, a heating jacket, a container containing a saturated inorganic salt solution, a strain demodulator, a power supply, a temperature controller, a strain sensor and a test piece, wherein the support comprises a positioning plate, an upper spherical hinge, an upper clamping head, a supporting rod, a bearing plate, a base plate, a lower clamping head and a lower spherical hinge; the supporting rod is connected with the bearing plate through a sliding bearing; the test piece is embedded in a groove in the upper clamping head and a groove in the lower clamping head; the weight is positioned on the bearing plate; the heating jacket covers on the outer side of the support; the container is positioned between the support and the heating jacket; the strain sensor is adhered to the outer wall surface of the test piece; and the temperature controller is connected with the ring-shaped heating jacket. By adopting the device, the reliability of the test process can be improved, and the accuracy of results is ensured. Meanwhile, the invention also discloses a test method for the test device. The method is simple and easy to operate, and can keep that the test piece does not generate stress relaxation in the process of long-term load application, and the stress is uniformly distributed.

Description

technical field [0001] The invention belongs to the technical category of material durability testing, and specifically relates to a testing device and a testing method for material creep under the coupled action of tensile stress and environment. Background technique [0002] For half a century, accidents caused by insufficient durability of cement-based materials have continued to increase, especially major projects such as dams, roads, bridges, ports, and high-rise buildings that have not reached the design life. Economic losses and casualties. The creep phenomenon of cement-based materials is one of the main reasons for the decrease of structural bearing capacity, premature structural failure and shortened service life. Although there have been decades of research on the creep of cement-based materials, most of the research work is to consider the creep development law under the action of a single environmental damage factor, and most of the creep loads are compressive ...

AI Technical Summary

Problems solved by technology

[0005] Combining the existing literature on the creep and deformation of cement-based materials, it is not difficult to find that most of the existing loading devices use spring loading, and there is no effective method to keep the stress constant during the test.

There are two main reasons: ①During the test, the material is constantly deformed, which directly affects the stress that the spring can provide, and what actually occurs is the relaxation of the material; ②Because of the loading stress, it is difficult to use gravity or leverage to load Way

[0006] The above shortcomings limit the correlation between laboratory studies and the creep and deformation laws of cement-based materials in the actual state

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