Nonlinear ultrasonic detection method and detection system suitable for concrete carbonization

Abstract

The invention provides a nonlinear ultrasonic detection method and system suitable for concrete carbonization, and belongs to the field of nondestructive detection. The detection method comprises the following steps that step 1, an arbitrary waveform generator is used for generating a sinusoidal waveform electric signal and outputting the sinusoidal waveform electric signal to a broadband power amplifier, the broadband power amplifier amplifies the electric signal, and the amplified electric signal is sent to a to-be-tested piece; step 2, the PZT piezoelectric ceramic chip at the transmitting end of the to-be-tested piece emits an ultrasonic signal after being subjected to an inverse piezoelectric effect, and the PZT piezoelectric ceramic chip at the receiving end of the to-be-tested piece receives the ultrasonic signal and converts the ultrasonic signal into an electric signal; step 3, the electric signal is transmitted into an oscilloscope, the parameter of the electric signal is displayed, the parameter of the electric signal is collected, and then FFT (Fast Fourier Transform) is performed to obtain a relative nonlinear parameter beta r of the to-be-tested piece; and step 4, the relative nonlinear parameter beta r is fit with concrete carbonization data obtained by the test, and the concrete carbonization time is obtained in the detection process according to beta r, thereby realizing nondestructive detection of concrete carbonization. According to the nonlinear ultrasonic detection technology provided by the invention, nonlinear parameters are obviously changed before and after concrete carbonization, and the nonlinear ultrasonic detection technology is suitable for evaluation of concrete carbonization.

Description

technical field [0001] The invention relates to the field of nondestructive testing of concrete, in particular to a non-linear ultrasonic testing method and a testing system suitable for carbonization of concrete. Background technique [0002] Reinforced concrete, as the most widely used, most cost-effective, and most used inorganic building material in the field of contemporary civil engineering, plays an indispensable role in the construction of large-scale infrastructure in my country and plays an irreplaceable role. The strength and durability of concrete are two important indicators of concrete structures, and the actual durability of concrete with the same strength indicator may vary greatly. With the widespread use of reinforced concrete, problems such as economic loss, resource consumption, and environmental damage caused by its lack of durability have long become one of the bottlenecks for the sustainable development of civil engineering. Carbonation, as a serious ...

AI Technical Summary

Problems solved by technology

There is also a nonlinear effect in the propagation of traditional linear ultrasonic waves in the periphery, but this nonlinear effect is extremely weak and cannot be reflected in the ultrasonic parameters.

At the same time, traditional linear ultrasonic testing does not pay attention to such nonlinear signals

However, when the large-scale high-energy ultrasonic wave penetrates into the solid medium, its propagation presents a strong nonlinear effect, which causes "twisting" distortion in the process of ultrasonic wave propagation, resulting in the formation of high-order harmonics

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