Detection of sleeve grouting connection defects in fabricated structural joints based on ultrasonic guided waves

Sleeve grouting is widely used for connecting prefabricated building components. Grouting defects have become an important factor affecting the application of grout sleeves. However, there is still a lack of monitoring methods for grouting defects in grout sleeves. In this paper, the ultrasonic guided wave method is used to detect grouting defects in the grout sleeve. The influence of the grouting defects on the guided wave signal is studied through experiments and simulations. Based on the differences between the guided wave signals of a healthy specimen and defective specimens, damage index values are proposed. The relation between the damage indexes and the mechanical properties is established via grouting sleeve monotonic tensile tests. The idea of using the analytic hierarchy process to complete a structural health evaluation is advanced. Both the experimental results and the simulated results show that there is relevance between the damage index and grouting defects. When the defect increases, the damage index value will increase significantly. The ultrasonic guided waves can effectively detect grouting defects in grout sleeves. (paper)