Research Progress on Defect Detection Methods for Rebar Grouting Sleeve Connections

Abstract

Against the backdrop of the rapid development of prefabricated buildings, internal defects in rebar grouting sleeve connections pose a serious threat to structural safety and durability. This paper systematically reviews key research directions concerning grouting sleeve connections with defects, with a particular focus on defect detection technologies. The study organizes and comparatively analyzes current mainstream non-destructive and semi-destructive testing methods, including ultrasonic testing, impact echo method, embedded sensor method, X-ray testing, piezoelectric impedance method, embedded steel wire pull-out method, and drilled bore endoscopy method. The research indicates that each method has its own characteristics and applicable scenarios: the piezoelectric impedance method can achieve quantitative evaluation of defect severity and is suitable for monitoring critical nodes; the impact echo method is sensitive to density but its positioning accuracy is influenced by sleeve arrangement; X-ray testing provides intuitive imaging but is costly and limited to laboratory use; drilled bore endoscopy allows direct observation of defect location and size, guiding repairs; the embedded steel wire pull-out method is easy to operate but only allows qualitative judgment. The study points out that a single detection method is difficult to meet complex engineering requirements. It is necessary to select or combine multiple methods according to specific application scenarios to leverage their complementary advantages, providing theoretical basis and technical support for improving acceptance standards for grouting sleeves, determining defect repair thresholds, and ensuring the safe application of prefabricated structures.