Corrosion damage assessment method for steel guardrail post roots

Steel guardrail posts are typically used on the highway system of Japan, but these can experience the corrosion damage at their root near the road surface. This damage may be particularly severe in the seaside areas or regions that experience cold weather and employ salt as a deicing agent. Therefore, this study aimed to develop a non-destructive way of estimating the extent of corrosion in the guardrail post roots. Particularly, 11 test specimens were parametrically designed to investigate the efficiency of using the impact vibration mode to assess the corrosion damage. The corrosion angle, range and thickness at the post root were the main parameters. Meanwhile, a parametric FEM analysis was executed as well to analyze the vibration behavior, the stiffness and the load-carrying capacity. In general, the study reveals that the high-order vibration modes are sensitive to the corrosion damage at the guardrail post roots, and based on this, an impact vibration method for assessing the corrosion damage was proposed.