Test device of load-deformation complete curve for testing four-point flexural-tensile concrete sample

Abstract

The present invention discloses a test device of a load-deformation complete curve for testing a four-point flexural-tensile concrete sample. The device comprises a steel plate, first round steel, second round steels, third round steel and a pressure sensor. The second round steels are fixed at two sides of the steel plate, the pressure sensor is arranged between the second round steels, the pressure sensor is fixed on the steel plate through the third round steel, and the top portions of the second round steel and the pressure sensor are provided with the first round steel configured to put aconcrete sample. The device is simple in processing, and low in manufacturing cost, can be customized according to the size of the concrete sample, namely can be used for measuring the whole curve ofa wet sieving concrete small sample, and can be also used for measuring the whole curve of a full-level matched concrete large sample; and moreover, the device provided by the invention can perform test in a common concrete test machine having no limitation for the ultimate load and the clearance of the test machine to achieve stable damaging of the concrete sample, and therefore, the test deviceof the load-deformation complete curve for testing the four-point flexural-tensile concrete sample is specially suitable for test rooms short of test conditions (implosion test machines).

Description

technical field [0001] The invention relates to the technical field of concrete specimen experiments, in particular to a test device for testing the full load-deformation curve of a four-point bending-tension concrete specimen. Background technique [0002] The full load-deformation curve (including the rising section and the falling section) of the concrete tensile failure process can macroscopically reflect a series of processes such as its deformation at each stress stage, the development of internal micro-cracks, damage accumulation, and final failure. The development process and failure mechanism of concrete internal damage are of great significance. At the same time, it is an important parameter for analyzing and calculating the bearing capacity and deformation of concrete structures. Testing the full load-deformation curve of concrete specimens can obtain the fracture energy and The ultimate tensile value provides reliable mechanical parameters for the analysis and re...

AI Technical Summary

Problems solved by technology

[0003] However, testing the full load-deformation curve of concrete specimens has high requirements on the stiffness of the testing machine. Even ordinary concrete specimens (wet screened specimens) are difficult to obtain full load-deformation curves and fully graded concrete loads on ordinary testing machines. - It is even more difficult to test the full curve of deformation, so in the research history of the full curve, how to improve the stiffness of the test device was once the most concerned by researchers

[0004] At present, the modified testing machines with rigid components connected in parallel to ordinary testing machines can achieve good results in the testing of small-sized concrete specimens, but the testing of large-sized fully graded concrete components is obviously insufficient. These testing machines cannot guarantee the overall During the experiment, the elastic energy stored in the testing machine will not be released suddenly, and the cracking process of the concrete specimen will be delayed, and the stable failure of the concrete specimen cannot be achieved.

Although some servo universal testing machines imported from abroad can test the full load-deformation curve, due to the high cost of imported testing machines, and the limit load and headroom of the testing machine are limited, the headroom is too small, so only the end-glued steel plate can be used. The test is very prone to end damage, resulting in test failure

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