Techno Press
Techno Press

Earthquakes and Structures
  Volume 28, Number 6, June 2025 , pages 507-520
DOI: https://doi.org/10.12989/eas.2025.28.6.507
 

 open access

Development of an image-based automatic reinforcement modeling and inspection (I-ARMI) technique
Jaehee Choi, Kun-Ho E. Kim, Young K. Ju, Sanghee Kim and Donghyuk Jung

 
Abstract
    Inspecting the accuracy of reinforcing bar placement in reinforced concrete (RC) structures is a critical procedure for ensuring the safety of structures. However, the current inspection methods are time-consuming and labor-intensive. Recent studies have been exploring the use of 3D scanners and depth cameras as inspection tools for reinforcing bars. Although there has been extensive research on bar length and spacing, limited numbers of studies have been carried on diameter detection, and they showed relatively low accuracy, especially for smaller bar diameters (D10 and D13). This study presents a photogrammetry-based automatic reinforcing bar information detection technique. By using readily accessible smartphones, images are acquired to generate 3D point clouds, and then automatic inspection procedures for bar diameter, length, and spacing are conducted. The efficacy of the proposed technique is experimentally investigated through the verification on laboratory-scale specimens (grid-type bar assembly and steel cage). It showed an accuracy of 97% in length and spacing the estimation of steel bars. Furthermore, it can effectively differentiate the diameter of D10 and D13 bars. This technique is expected to be utilized for accurate and rapid reinforcing bar placement inspections on construction sites.
 
Key Words
    3D modeling; image processing; photogrammetry; point cloud data; reinforcing bar inspection
 
Address
Jaehee Choi: Department of Civil, Environmental and Architectural Engineering, Korea University, Seoul 02841, Korea
Kun-Ho E. Kim: Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, ON, Canada N2L 3G1
Young K. Ju and Donghyuk Jung: School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 02841, Korea
Sanghee Kim: Department of Architectural Engineering, Kyonggi University, Suwon 16227, Korea
 

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