Quantitative scaling evaluation of concrete structures based on terrestrial laser scanning

• Laser scanning is practical in scaling evaluation of concrete structures.
• Total scaling depth can be evaluated with approximately 2 mm accuracy.
• Secular change can be evaluated by aligning and comparing time series scans.

Scaling of old concrete structures, such as road bridges, is especially conspicuous in cold districts. It is a type of damage where near-surface portions of structures have locally flaked or peeled away, caused mainly by freeze–thaw cycles and deicing chemicals. In this paper, we propose effective methods for the quantitative evaluation of the scaling of concrete structures based on terrestrial laser scanning. We first present a method for evaluating the total scaling depth of concrete structures from their original states based on our customized region growing algorithm. We also present a method for evaluating secular changes in scaling depth based on iterative closest point algorithm combined with a novel feature sampling technique from the time-series scans of structures, and demonstrate the effectiveness and accuracy of the proposed methods through various experiments.