Tester for concrete free deformation

Abstract

The invention discloses a tester for concrete free deformation which has low manufacturing cost, high measuring precision, and easy operation for engineering personnel, and comprises a test box assembly, a temperature controlling assembly, a displacement sensing device, and a computer assembly. The test box assembly is a detachable closed container, and is composed of six movable assembled side plates; the temperature controlling assembly comprises an AC electric power regulator which can be controlled by the computer assembly, a silicone rubber heating film, a temperature signal conditioner, and a temperature sensor; the displacement sensing device is a displacement sensor which is disposed at the end part of a concrete test object and is in intimate contact with the object. The invention can simulate the in situ temperature of the concrete structure and measure the free deformation, has the advantages of low manufacturing cost, high measuring precision, and easy operation for users, can provide experimental basis for the optimization of mix proportion of concrete, and can furthest ensure the prevention or the inhibition of the expansion of concrete cracks so as to achieve the purpose of improving the control level and durability of concrete temperature cracks.

Description

Technical field [0001] The invention relates to a test instrument for experiments in the field of building materials, which is mainly used to measure the free deformation of concrete experimental equipment, in particular to a test instrument that simulates the temperature development of various volume concrete structures in a laboratory and measures the free deformation thereof. Background technique [0002] The free deformation of concrete is one of the important indicators to measure whether the concrete mix ratio is beneficial to reducing the risk of cracking of large-volume concrete structures. It is composed of temperature deformation, autogenous shrinkage and drying shrinkage. It also includes artificial expansion and deformation when an expansion agent is added. Only under the premise of understanding the free deformation of concrete, can we combine the actual degree of restraint and the influence of concrete elastic modulus and creep and other physical characteristics to d...

AI Technical Summary

Problems solved by technology

The reliability and accuracy of the test results depend on whether the heat release rate can be well controlled. However, the existing instruments only measure concrete at room temperature, and cannot give the concrete test object a test environment that meets the semi-adiabatic temperature rise condition.

[0005] The second is the limitation of measurement materials: some existing shrinkage testers are mainly used for mortar tests, or to limit the particle size of aggregates. Obviously, this measurement and simulation method does not consider the influence of stones in concrete on the deformation of concrete itself. Therefore, it is not practical to measure the shrinkage deformation value of concrete

[0006] The third is the lack of concrete simulation state: some existing concrete deformation instruments are tested after the concrete is hardened and demoulded, and cannot measure the complete free deformation

Current concrete deformation testing instruments cannot measure these deformations

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