Detection of Sleeve Grouting Compactness Based on Acoustic Emission Technology
Aiping Yu1,2,3,4, Xianghao Li1, Feng Fu1,5
1College of Civil and Architecture Engineering, Guilin University of Technology, Guilin 541004, China.
Materials (Basel, Switzerland)
|February 25, 2023
Summary
This study introduces acoustic emission (AE) technology to detect sleeve grouting compactness. The method effectively identifies defects, with signal characteristics correlating to grout quality and defect size.
Area of Science:
- Civil Engineering
- Materials Science
- Non-destructive Testing
Background:
- Sleeve grouting compactness is crucial for rebar connection mechanical properties.
- Current methods for detecting internal sleeve grouting compactness are insufficient.
Purpose of the Study:
- To propose a novel acoustic emission (AE) detection technology.
- To assess AE signal characteristics for identifying horizontal and vertical defects in sleeves with varying grout compactness.
Main Methods:
- Analysis of basic AE signal waveform characteristics.
- Wavelet packet decomposition of AE signals.
- Construction of a grouting compactness index based on wavelet packet energy ratio.
Main Results:
- AE signal count decreases with increased grouting compactness.
- Defect reduction rates differ between horizontal and vertical defects.
- Acoustic emission signal frequency composition shifts with increasing compactness.
- The developed compactness index shows an exponential decrease with rising compactness and correlates with defect size.
Conclusions:
- The proposed AE method is effective for detecting sleeve grouting defects.
- The technique offers a new approach for assessing grout compactness and identifying internal defects in sleeves.
Related Concept Videos
01:23Measurement of Air Content in Concrete
218
Air content measurement in concrete is critical for ensuring structural integrity and durability of concrete structures, especially in environments prone to severe weather conditions. Accurate air content analysis optimizes concrete's resistance to freeze-thaw cycles and enhances its workability and strength. Several methods are standardized under ASTM guidelines to measure the air content in fresh concrete, each suitable for different concrete types and conditions.
The pressure method,...
The pressure method,...
218
01:17Soundness of Cement
213
The soundness of cement refers to the ability of cement paste to retain its volume after setting. Unsound cement can lead to expansion and structural damage due to the presence of free lime, magnesia, and calcium sulfate. Free lime hydrates very slowly, expanding and causing unsoundness, which is difficult to detect because it intercrystallizes with other compounds. Magnesia also reacts with water, forming crystals that can disrupt the cement's structure. Calcium sulfate can create...
213
01:20Microcracking in Concrete
173
Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30...
173
01:12Non-destructive Tests for Concrete Strength
165
The rebound hammer test, also known as the Schmidt hammer test, is a non-destructive technique for evaluating the hardness of concrete and, indirectly, the strength of concrete. It operates on the principle that the rebound of a spring-driven mass from a concrete surface correlates to the surface's hardness. The device comprises a mass within a tubular housing, a spring mechanism, and a plunger that strikes the concrete. Upon release, the energy imparted to the mass by the spring causes it...
165
01:16Dynamic Modulus of Elasticity of Concrete
451
The dynamic modulus of elasticity assesses how a concrete structure deforms under impact or dynamic loads. It is typically higher than the static modulus of elasticity, measured under slow, steady loading conditions.
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by...
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by...
451
01:23Abrasion Resistance of Concrete
173
Abrasion resistance is an essential characteristic of concrete that determines its durability and longevity under various wear conditions. Concrete surfaces are vulnerable to different types of abrasion. For instance, surfaces may wear down due to the constant movement of vehicles or be eroded by solids carried in water, as seen in concrete canal linings. Specific tests are conducted to measure the abrasion resistance of concrete.
One such test is the revolving disc test, where three plates...
One such test is the revolving disc test, where three plates...
173