In Situ Monitoring of Anodic Acidification Process Using 3D μ-XCT Method

Area of Science:

• Materials Science
• Corrosion Engineering
• Civil Engineering

Background:

• Anodic acidification is a key failure mechanism in impressed current cathodic protection (ICCP) systems for reinforced concrete.
• This process can lead to anode debonding, compromising structural protection.

Purpose of the Study:

• To monitor the in situ evolution of the anodic acidification-affected zone in ICCP systems.
• To quantify the volume and analyze the spatial heterogeneity of this zone.
• To establish a relationship between the affected zone and input electrical energy for durability estimation.

Main Methods:

• Utilized 3D micro X-ray computed tomography (μ-XCT) for in situ monitoring.
• Employed gray level segmentation to identify the affected zone in μ-XCT images.
• Applied 3D reconstruction for volume measurement and spatial heterogeneity analysis.

Main Results:

• Detailed 3D information of the affected zone was successfully extracted.
• The affected zone volume was found to be proportional to the input electrical energy.
• Faraday efficiency increased after 20 days of operation.

Conclusions:

• 3D μ-XCT is effective for analyzing anodic acidification effects in ICCP systems.
• The proposed model aids in estimating the durability of ICCP systems by correlating affected zone size with energy input.
• Understanding the spatial heterogeneity is crucial for predicting system performance.