Applicability of 3-D Scanning Technology for Section Loss Assessment in Corroded Steel Beams

Abstract

Corrosion at beam ends is one of the most widespread causes of damage in steel bridges. Accurate determination of the level of section loss caused by corrosion damage is critical for estimating the bearing capacity and load rating of a bridge. Current evaluation methods are labor intensive and dependent on subjective assessments by inspectors. Unique features of structured-light 3-D scanning technology offer significant potential for application in bridge inspections and corrosion damage assessment. 3-D scanners are able to provide accurate information on the pattern and amount of section loss at beam ends. However, the promise and applicability of this technology has not been investigated. In this study, a structured-light scanner was used in a trial application to evaluate its ability to create accurate, high-resolution 3-D representations of locally corroded steel beams. Scanning was performed in both a laboratory setting and on two bridges in Connecticut. The 3-D models were used to extract information such as the maximum reduction in thickness and the pattern of corrosion. This paper discusses results, observations, and recommendations for the adoption of structured-light scanning for corrosion damage assessment in bridges. The scanning data provides an enhanced form of inspection documentation including accurate representations of spatial details and colors. It is expected that the material presented in this paper facilitates the adoption of this promising technology for bridge inspection.