Assessment of Corrosion in Prestressed Concrete Piles in Marine Environment with Acoustic Emission

摘要

Corrosion of prestressed concrete (PC) piles in splash zones is one of the main causes of bridge deterioration in marine environments. Acoustic Emission (AE) monitoring is a promising technology for detecting corrosion damage in concrete nondestructively. The monitoring of corrosion and associated cracking in PC piles is facilitated by the service load conditions, where compressive loads from the prestressing forces combined with dead loads are predominant, and flexural cracking becomes less relevant, thereby reducing sources of AE. This paper presents the experimental design for a pilot research investigation aimed at investigating the capabilities of AE to detect, characterize, and locate corrosion of longitudinal reinforcement in PC piles in marine environments. Scaled PC specimens representative of prestressed piles were designed to produce damage mechanisms and AE sources in the laboratory similar to those encountered in actual PC piles in contact with salt water. A chloride-penetration model was used to design the concrete cover to minimize the corrosion initiation. An experimental setup was designed to have the specimens in direct contact with salt water simulating tidal action. The setup includes an AE monitoring system, with benchmark corrosion measurements being provided through standard half-cell potential and linear polarization resistance measurements.