Standard unit and method for testing the contact state of the inner wall of concrete micro-cracks in vibration

Abstract

The invention discloses a standard unit and a method for testing the contact state of the inner wall of concrete micro-cracks during excitation, and belongs to the technical field of hidden crack detection in concrete engineering; the standard unit for testing the contact state of the inner wall of concrete micro-cracks during excitation includes concrete micro-crack standards Body, metal film, farad capacitor, battery, wire and multimeter. The metal film covers the inner wall on both sides of the crack in the concrete micro-crack standard body. The metal film, farad capacitor and battery are connected by wire to form a test circuit. The multimeter is used for Measure the voltage at both ends of the capacitor; the invention effectively solves the problem that it is difficult to judge the contact and collision of the two side walls of the unclosed concrete micro-cracks in the excitation of mechanical waves such as ultrasonic waves in the prior art; test the concrete micro-cracks whose inner wall is covered with a metal film in the standard unit When the contact state of the inner wall is stimulated to vibrate, the judgment result is obtained, and the result can be mapped to the concrete crack of the same width under the same excitation condition and boundary condition.

Description

technical field [0001] The invention relates to the technical field of hidden crack detection in concrete engineering, in particular to a standard unit and a method for testing the contact state of the inner wall of concrete micro-cracks during excitation. Background technique [0002] Microcracks in wading concrete projects not only damage the bearing capacity of the structure, but also serve as a channel for environmental corrosion factors to extend into the structure. The coupling of the two destructive effects often intensifies the structural safety risk; therefore, microcracks growing on important parts of key components are It is a serious hidden danger of inducing hydraulic structural engineering accidents, but it is very difficult to detect. When concrete microcracks are found, safety diagnosis can be carried out as early as possible, and risks can be predicted in time. In recent years, a lot of research has been done on the detection of concrete micro-cracks based ...

AI Technical Summary

Problems solved by technology

In recent years, a lot of research has been done on the discovery of concrete micro-cracks based on ultrasonic-induced infrared thermography, but this method has not been widely used in engineering. One of the important reasons is that the heat generation mechanism of concrete micro-cracks under ultrasonic excitation has not been thoroughly grasped.

The key to restricting the research on the heat generation mechanism is that the contact and collision of the two side walls of the unclosed concrete micro-cracks under ultrasonic excitation cannot be effectively tested.

Images