X-ray analysis as a fast validation tool for in-situ connections in modular wooden buildings

The global demand for sustainable, efficient, and rapid construction solutions has driven the increasing adoption of modular building systems, particularly in response to urban development and housing shortages. In this context, modular wooden construction has emerged as a promising alternative, offering environmental benefits and streamlined assembly processes. However, ensuring the structural integrity of inter-module connections remains a critical challenge, especially in multi-story buildings, due to practical constraints on construction sites. Therefore, this short communication aims to evaluate the use of digital X-ray analysis as a fast, non-destructive, in-situ method for validating the self-locking connectors in modular wooden buildings. For this experiment, a full-scale two-story structure was built and assembled using prefabricated volumetric wooden modules with steel self-locking connectors. Post-assembly, a SENTINEL 880 Series Delta Gamma-Ray Source Projector (Iridium-192) and an HPX-DR non-glass detector were used to scan the connections. High-resolution radiographic images revealed secure engagement of all inspected connectors, including those initially suspected of improper connection. First-floor connectors showed consistent integrity, likely due to compressive forces from upper modules aiding the connection. Digital X-ray analysis proved to be a rapid and effective tool for on-site verification, offering advantages in space efficiency, simplified assembly, and scalability.