Testing device and method of comprehensive deformation performance of pressed concrete and similar materials

Abstract

Provided is a testing device of comprehensive deformation performance of pressed concrete and similar materials. The testing device comprises a cushion plate arranged at the top of a test piece, axial electronic displacement meters are arranged at different positions below the cushion plate, horizontal fixing frames are arranged at the positions corresponding to the axial electronic displacement meters, fixing devices for fixing the horizontal fixing frames to the test piece are arranged on the horizontal fixing frames, radial electronic displacement meters are further fixed to the horizontal fixing frames, and the radial electronic displacement meters and the axial electronic displacement meters are connected with a strain collecting instrument. Axial deformation and radial deformation of the test piece at different heights are fully considered, the size deformation and other comprehensive deformation features of the test piece are measured in real time in the load applying process, the whole process of axial and radial deformation development of the test piece at different heights can be analyzed in details in the load applying process, the size change process of the test piece can be analyzed, and the precision of test piece size measurement is improved.

Description

technical field [0001] The invention belongs to the technical field of material mechanics test, in particular to a test device and method for comprehensive deformation performance of concrete and similar materials under compression. Background technique [0002] Concrete and similar materials (e.g. rock, earth) are widely used in industrial and civil construction. These materials have a typical characteristic of high compressive strength but low tensile strength. The compressive performance of this type of material is one of the main manifestations of its excellent mechanical properties, the main parameter to characterize its mechanical properties, and an important aspect for in-depth understanding of this type of material, which is extremely important for theoretical research and engineering applications. The elastic modulus (deformation modulus) and Poisson’s ratio of ordinary concrete and similar materials (such as rocks) have clear test methods and calculation formulas i...

AI Technical Summary

Problems solved by technology

[0006] There are four main disadvantages of the first method of measuring the volume deformation of the test piece by the sticking strain method: 1. The length of the axial strain gauge is limited and cannot reflect the deformation within the effective range of the test piece; 2. The radial strain gauge is mainly located in the middle of the test piece. , only the radial deformation of this part can be tested

The research results show that the radial deformation of the test piece at different heights is not uniform, and the radial deformation of the middle part cannot be equal to the radial deformation of the test piece, sometimes the difference is large, so the calculation of the volume deformation by this method will inevitably lead to errors 3. After cracks are formed on the surface of the specimen, the strain gauge is partially separated from the specimen, and the strain gauge fails and cannot be used any longer; 4. Some special concretes are not suitable for testing deformation by the sticking strain method, such as those with low strength, Plastic concrete with large deformation, poor surface properties, and weak adhesion of strain gau

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