Concrete-filled steel tubular (CFST) structures are essential load-bearing components in
many civil engineering structures. Subsurface voids between the contacting surface of the
concrete and steel in a CFST structure reduce the load-bearing capacity of the CFST
structure. This paper presents a novel, non-destructive, percussion-based approach to
detect subsurface voids in CFST structures. In our approach, we exploit the contrasting
sound produced by the percussion of surfaces with and without subsurface voids …

The void defects significantly threaten the integrity of concrete-filled steel tubular (CFST)
structure. Along with detecting the presence of subsurface voids, the knowledge of the
geometry of voids can provide meaningful information to determine the overall structural
health. This study develops a method to determine the depths of subsurface voids by
integrating the percussion technique with a machine learning algorithm. A decision tree
model is trained to detect different depths of subsurface voids in a CFST specimen. The …