Constraint handling device for biaxial tension and compression concrete test piece

Abstract

The invention discloses a constraint handling device for a biaxial tension and compression concrete test piece. The device comprises two first structural unit sheets, two second structural unit sheetsand a first third structural unit sheet. The third structural unit sheet is arranged horizontally as a bottom structure of the device, and a reserved test piece position line is arranged in the middle for positioning and placing the concrete test piece; snap joints connected to the third structural unit sheet are arranged on the bottom edges of the first structural unit sheets and the second structural unit sheets; two side edges of the first structural unit sheets are detachably connected to one side edges of the two second structural unit sheets, separately, to form a square side frame structure, and sticky gypsum pouring space is formed among the concrete test piece, the first structural unit sheets and the second structural unit sheets. By attaching a protecting layer to the tensionedand compressed surface of the concrete test piece, the anti-attrition constraint action of a loading plate on concrete can be improved effectively, so that the testing accuracy of a test is improved.

Description

technical field [0001] The invention relates to the technical field of concrete tests, in particular to a restraint processing device for concrete biaxial tension and compression test pieces. Background technique [0002] As we all know, concrete is a composite material prepared by cementitious material, fine aggregate, coarse aggregate, water and admixture in a certain proportion. Compared with other building materials, concrete has the advantages of convenient materials, easy pouring, good fire resistance, good resistance to cyclic loads, economical benefits, and low maintenance requirements. Therefore, it has been widely favored since its inception, and is widely used in buildings and structures such as industrial and civil buildings, bridges and tunnels, concrete dams, coastal engineering and nuclear containment. During the service period, in addition to static loads, concrete structures may also be subjected to dynamic loads, such as earthquake loads, explosion loads, ...

AI Technical Summary

Problems solved by technology

In 2015, Zhou Jiajia, a doctoral student of Southeast University, "Mechanical Performance Test and Theoretical Research of High-strength and High-performance Concrete under Multiaxial Stress State", in the biaxial tension and compression test, a prism specimen of 150mm ´ 150mm´ 50mm was used. Structural glue bonded the specimen to the load-transmitting plate (aluminum block), and obtained the bonding strength after curing for 24 hours, and the connection method of the externally attached steel block was used for loading, but in the tensile direction of the specimen, the surface of the specimen was not Flat, and the loading plate on the compression surface will cause friction to the specimen, which will affect the experimental results

In "Experimental Research on Dynamic Biaxial Tension and Compression Performance of Large Aggregate Concrete" published by Chen Renjin in 2015, the specimen used was a 250mm´ 250mm´ 400mm prism, and bolt holes were reserved on the tensile surface of the specimen to connect with the loading plate. A layer of plastic film and glycerin is attached to the pressure surface for friction reduction treatment. However, bolt holes are reserved for the tension surface. This area is prone to stress concentration during the test, which affects the test results. Lubrication will not reduce the restraint of the loading plate on the free deformation of the specimen

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