Test on Detection of Grouting Compactness of Grout Sleeve by Impact-echo Method

A series of experiments on grout sleeve specimens with different types and different grouting compactness were carried out based on impact-echo method. Test results show that the impact-echo method is able to give a good qualitative judgment for specimens with the steel sleeve in the middle, with or without reinforced bars, but there are some errors in the quantitative analysis between the test result and the actual situation. For specimens with grout sleeve double row arrangement, it is difficult to distinguish the grouting zone and the non-grouting zone based on the test results. Overall, the impact-echo method is feasible to detect the grouting compactness of grout sleeve to some extent, but some further research on the testing and analysis method is still needed for its accuracy and reliability to be improved.