Project 35.003 – Structure and Sub-Grade Corrosion Management

Development of a Web-Based Steel Pole Strength Loss Calculator: Utilization ratios are a key metric for determining whether corrosion-related section loss has rendered a steel pole unacceptable for continued service. This task will deliver a structure health assessment tool in the form of a web-based calculator designed for asset managers, engineers, and maintenance personnel. The calculator will integrate inspection data describing corrosion damage, structural loading criteria, original design parameters, and environmental inputs related to soil corrosion rates to evaluate remaining structural capacity. EPRI plans to deploy this tool on the Transmission Resource Center in 2027.

Evaluation of New and Emerging Coating Systems for Atmospheric, Subgrade, and Marine Environments: EPRI annually evaluates new and emerging coating systems for potential inclusion in its coating library. While many systems are intended for factory applications, others are suitable for field repair and refurbishment. This task enables utilities to select coating systems optimized for performance within their specific service environments. Results will be incorporated into updates of the web-based Coating Selection and Application tool hosted on the Transmission Resource Center.

Fleet Management of Overhead Transmission Line Structures: Effective fleet management requires not only inspection and maintenance practices, but also analytical auditing to identify optimal approaches for modeling degradation and extending structural service life. This task will enhance existing modeling capabilities by incorporating the effects of topography, surface water, and groundwater into soil corrosivity maps and predictive models.

Engineered Backfills and Conductive Concrete: Research conducted to date indicates that electrical conductivity and compressive strength exhibit an inverse relationship as the water-to-cement ratio is varied. This finding enables both grounding and structural engineers to identify balanced design solutions that optimize cost and performance. The task involves aging concrete cylinders containing embedded steel coupons representative of reinforcing steel, followed by periodic corrosion rate measurements. These measurements are validated through coupon removal and mass loss determination using gravimetric analysis.

Corrosion from Stray Direct Currents and Circulating Alternating Currents: This task continues research initiated in 2025 to evaluate emerging methods and technologies for identifying and quantifying corrosion currents associated with stray DC and induced AC interference. The resulting insights will enable utility advisors to implement more effective mitigation strategies and extend the service life of affected assets.

Investigate Degradation of Anchors and Helical Piles: This task explores the mode of failure for various anchor designs and helical piles to determine if that anchor is at risk due to stray or circulating current corrosion. This task is based upon new learning that will allow utilities to understand why anchor systems degrade and how to mitigate that corrosion. EPRI intends to focus research in 2027 on understanding circulating and stray currents in high soil resistivity and high ground water levels and publish the Anchor Management Guidelines.

Update the Corrosion Management Reference Book (The Rust Book): This reference book contains asset management information for inspection, assessment, mitigation, and remediation of corrosion on transmission lines. The reference book contains the fundamentals of corrosion, guidance for inspection and assessment, and mitigation methods that align with environmental conditions. EPRI intends on adding a new chapter focused upon the development and operation of the EPRI developed Corrosion Monitoring System (CMS) in 2027.

Corrosion and Corrosion Control Workshop: This workshop provides an understanding of corrosion fundamentals and the best-in-class methods for corrosion management. The fundamentals of corrosion include why corrosion initiates, what governs the severity and quantifies the environments in terms of corrosion rates. Hands on experiments are conducted to understand cathodic protection and how to inspect and quantify a condition assessment. The last segment focuses upon mitigation methods and how to effectively apply the appropriate method in each environment.

Provide Tools and Resources on the Transmission Resource Center: The following calculators, tools, result summaries and references are planned to be available on the Structure and Subgrade Corrosion Management Transmission Resource Center: