Method for measuring absolute stress of concrete under uniaxial stress by applying ultrasonic scattering wave method

Abstract

The invention discloses a method for measuring absolute stress of concrete under uniaxial stress by applying an ultrasonic scattering wave method. The method comprises the following steps: firstly, providing a standard concrete test block which is consistent with a to-be-tested concrete member, and performing an ultrasonic scattering wave test in a first loaded mode; secondly, drawing original waveform diagrams in various load states and a relationship curve of scattering wave travel-time difference change rate and stress; thirdly, performing the ultrasonic scattering wave test on the to-be-tested concrete member in a second loaded mode, wherein the second loaded mode is contained in the first loaded mode; fourthly, drawing original waveform diagrams of the to-be-tested concrete member in various load states and a relationship curve of the scattering wave travel-time difference change rate and the stress; fifthly, finding the initial position of the relationship curve of the scattering wave travel-time difference change rate and the stress of the to-be-tested concrete member on the curve of the standard concrete test block, wherein the stress value corresponding to the initial position is the absolute stress. The method can evaluate the absolute stress of the to-be-tested concrete member.

Description

technical field [0001] The invention relates to the field of non-destructive testing of concrete, in particular to a method for measuring the absolute stress of concrete under uniaxial compression by using an ultrasonic scattered wave method. Background technique [0002] Due to the complexity of the concrete material, complex reflection, refraction, and scattering will occur when ultrasonic waves propagate in it, which brings great challenges to the accurate measurement of ultrasonic wave velocity changes. The ultrasonic scattered wave method can just solve this problem. The small stress change of concrete has the advantages of high precision and high sensitivity. [0003] The ultrasonic scattered wave method uses the scattered waves formed by multiple scattering to study the medium. Due to the long propagation path, it can amplify the small changes inside the concrete medium, so it is very sensitive to the weak changes inside the structure, while the conventional method ca...

AI Technical Summary

Problems solved by technology

At present, the degree of damage is mainly determined by detecting cracks, cavities, and internal steel corrosion, but the above parameters cannot directly reflect the real stress state of the concrete structure

The cross-sectional stress of concrete bridges under permanent action is a key indicator for assessing the bearing capacity of in-service bridges. The problem of measuring cross-sectional stress has not been effectively resolved, resulting in the inability to accurately assess the bearing capacity of in-service concrete bridges during the testing process.

Images