CONTACT US AiMS LOGIN

Archive

‘Out of Joint’ – Managing Corrosion in Bridge Joints

‘Out of Joint’ – Managing Corrosion in Bridge Joints

Based on the paper 'Investigation, Mitigation and Management of Corroding Bridge Joints in Leicestershire', presented at the Highways Maintenance Engineers Conference at Nottingham University, 7-9th September 1998.

Bridge structures are designed to last decades, but one persistent issue continues to threaten their durability: corrosion caused by salt-laden water leaking through joints. Over time, this accelerates the deterioration of embedded steel reinforcement, putting structural integrity at risk. A project on the M1 motorway in Leicestershire, UK, offers a compelling case study in how innovative engineering, specifically impressed current cathodic protection (ICCP), can address this challenge effectively and with minimal disruption.

The Problem: Hidden but Severe Corrosion

Bridges built in the 1970s, though innovative for their time, included design features like half-joints and concrete hinges that have proven vulnerable. Water carrying de-icing salts seeps through joints, reaching deep into the structure and triggering corrosion.

Inspections revealed:

  • Cracking and spalling concrete
  • Rust staining on soffits (undersides)
  • Severe pitting corrosion in reinforcing bars
  • High chloride concentrations deep within joints

In some cases, corrosion was occurring in areas not detectable through standard surface inspections, making the problem even more dangerous.

Engineers conducted detailed testing on the River Avon Viaduct, including:

  • Half-cell potential mapping (surface and deep-hole)

  • Chloride concentration analysis

  • Targeted drilling into critical joint areas

These tests confirmed that corrosion was most severe deep within the half-joints, especially near key structural interfaces.

To stop corrosion at its source, engineers implemented ICCP, a technique that applies a small electrical current to the steel reinforcement, preventing it from corroding.

A major challenge was delivering protection deep within the structure. The solution came in the form of conductive ceramic “discreet anodes”, inserted into drilled holes. This approach allowed engineers to target the most vulnerable zones directly, rather than relying on surface treatments.

The system didn’t stop at installation. It included a networked monitoring system that allows engineers to track corrosion rates in real time, adjust electrical current remotely, receive alerts if performance drops and manage multiple bridges from a central location. This marked an early move toward digitally managed infrastructure.

One of the most impressive aspects of the project was execution. Most work was done from beneath the bridge with minimal impact on motorway traffic and the system fully operational within schedule.

The ICCP system proved highly effective:

  • Successfully halted corrosion in critical areas
  • Provided long-term protection with minimal maintenance
  • Cost less than traditional repair methods
  • Scalable to other bridges across the network

Following this success, similar systems were installed on additional bridges along the M1.

 

Why This Matters?

This project demonstrates a shift in infrastructure management.

From reactive repairs → to proactive, long-term protection
From manual inspections → to smart, remote monitoring
From disruptive works → to minimal-impact solutions

As infrastructure ages worldwide, approaches like ICCP offer a sustainable and cost-effective way to extend the life of critical assets.

Read our full article, ‘Out of Joint’, published by Concrete Engineering International here.

Preventing an Achilles Heel

Preventing an Achilles Heel

Surface-applied corrosion inhibitors are emerging as a flexible alternative to cathodic protection for reinforced concrete structures.

Corrosion of reinforced concrete remains one of the most persistent maintenance challenges facing bridge owners and infrastructure managers. While impressed current cathodic protection (ICCP) systems have long been regarded as a proven method of corrosion control, surface-applied corrosion inhibitors (S-ACIs) are increasingly being adopted as a complementary or alternative strategy.

A corrosion inhibitor is any substance which, when introduced into an environment at relatively low concentration, reduces existing corrosion and limits the risk of future deterioration. Although inhibitors have been widely used for decades in the petrochemical and transportation sectors, their use within reinforced concrete structures is comparatively recent.

The protection provided by reinforced concrete relies heavily on the highly alkaline environment surrounding the embedded steel reinforcement. Under normal conditions, this alkalinity maintains a stable passive oxide film on the steel surface, preventing corrosion. However, when carbonation or chloride contamination reduces alkalinity, corrosion can initiate, leading to cracking, spalling and eventual loss of structural capacity.

S-ACIs operate by interfering with the electrochemical corrosion process occurring between anodic and cathodic sites on the reinforcing steel. Depending on the formulation, inhibitors may act anodically, cathodically or as mixed inhibitors. The systems evaluated in this study were mixed inhibitors, designed to suppress both anodic and cathodic reactions simultaneously through the formation of a protective film on the steel surface.

Because mixed inhibitors do not necessarily create a significant shift in corrosion potential, the study emphasised the importance of monitoring corrosion rate rather than relying solely on half-cell potential measurements. Embedded corrosion rate sensors developed by C-Probe Technologies were used alongside the AchillesIES remote monitoring system to measure steel loss over time and evaluate treatment performance.

Field applications

Three bridge structures managed on behalf of the Highways Agency were monitored to assess the effectiveness of S-ACI treatments.

Twyford Bridge, Nottinghamshire

At Twyford Bridge, S-ACIs were trialled on suspended bridge slabs alongside an ICCP installation. Two products, Sika Ferrogard and Flexcrete MCI 2020, were spray-applied to opposite sections of the bridge soffit.

The soffit application proved difficult because of poor absorption into the concrete surface. Nevertheless, areas associated with newly grouted repairs showed significant reductions in corrosion rate, suggesting that diffusion pathways through repaired concrete improved inhibitor penetration.

Wansford Bridge, Cambridgeshire

Wansford Bridge formed part of a larger pilot study comparing ICCP systems and S-ACI technology. The inhibitor was applied to the deck soffit in two treatment coats.

Unlike Twyford, the inhibitor successfully diffused through the concrete cover and produced measurable reductions in corrosion activity. The project demonstrated that S-ACI treatments can perform effectively when the concrete condition allows adequate penetration to the reinforcement level.

Ranby Canal Bridge, Nottinghamshire

Ranby Bridge provided the most comprehensive assessment of S-ACI performance. The bridge structure, including abutment walls and soffits, was treated over approximately 500m².

In areas undergoing concrete repair, the inhibitor was applied directly to exposed reinforcement before patch repairs were completed. Additional surface treatment was then applied to surrounding concrete to create a long-term reservoir of inhibitor and reduce the risk of incipient anode formation adjacent to repair zones.

This direct-to-steel application produced the most significant performance improvements, with corrosion rates reduced by as much as 100-fold in some monitored locations.

Key findings

The study demonstrated that surface-applied corrosion inhibitors can significantly reduce reinforcement corrosion in reinforced concrete structures when correctly applied and monitored.

However, performance depends heavily on several factors:

  • The inhibitor must successfully reach the reinforcement surface.
  • Concrete porosity and cover depth strongly influence diffusion.
  • Moisture and oxygen availability affect corrosion activity and inhibitor demand.
  • Severely corroded structures may require excessive quantities of inhibitor to remain effective.

Direct application onto exposed reinforcement during concrete repair proved particularly effective, while surface-applied treatments alone achieved more moderate but still meaningful reductions in corrosion rate.

The study also highlighted the importance of long-term corrosion monitoring. Without reliable monitoring systems, infrastructure owners cannot accurately assess treatment effectiveness, determine reapplication intervals or optimise maintenance strategies.

Conclusion

Surface-applied corrosion inhibitors are not a universal replacement for cathodic protection, but they offer a flexible and potentially cost-effective addition to the corrosion management toolkit for reinforced concrete structures.

Where conditions are favourable, S-ACIs can extend service life, reduce corrosion rates and enhance the durability of repair works, particularly when used alongside embedded monitoring systems and targeted repair strategies.

The projects demonstrated that successful corrosion prevention relies not only on the treatment itself, but also on understanding how inhibitors interact with the concrete environment over time. Continuous monitoring remains essential to ensuring long-term performance and informing future maintenance requirements.

Read our article ‘Preventing an Achilles Heel’, published by Concrete Engineering International

Decarbonization of Cathodic Protection for the Built Environment

Decarbonization of Cathodic Protection for the Built Environment

View our LoCem® product range, our low carbon answer to decarbonizing cathodic protection.

Repurposed industrial waste materials are offering a lower-carbon future for cathodic protection systems in reinforced concrete and masonry structures.

Steel beam with corrosion defects

As industries worldwide respond to increasing pressure to reduce carbon emissions and meet net-zero targets, corrosion protection technologies are also undergoing significant change. Cathodic protection (CP), long recognised as one of the most effective methods of preserving reinforced concrete and steel-framed structures, has traditionally relied on non-renewable materials and energy-intensive manufacturing processes.

A new generation of sustainable alkali-activated cementitious materials (AACMs), often referred to as geopolymers, is now being developed to reduce the environmental impact of CP systems while maintaining long-term durability and performance.

The approach centres on repurposing industrial waste streams from sectors such as steel production, mining and fossil fuel generation to create conductive cementitious materials capable of functioning as both repair mortars and cathodic protection anodes.

Moving beyond traditional cathodic protection materials

Conventional sacrificial anodes used in cathodic protection systems gradually corrode during service and cannot be recycled once consumed. Similarly, impressed current cathodic protection (ICCP) systems often depend on titanium substrates coated with rare earth metal oxides, materials associated with significant environmental and resource pressures.

At the same time, ordinary Portland cement remains a major contributor to global carbon emissions, accounting for approximately 8% of worldwide CO₂ output.

AACMs offer an alternative route. Produced through ambient blending rather than high-temperature processing, these materials can reduce carbon emissions by more than 90% when compared with conventional Portland cement production.

In addition to their sustainability benefits, AACMs demonstrate strong engineering performance, including high compressive and flexural strength, low shrinkage, excellent chemical resistance and fire resistance exceeding 1,200°C.

Conductive geopolymer anodes

One of the most significant developments is the use of conductive AACMs as cathodic protection anodes.

The highly alkaline nature of the material allows it to activate zinc galvanic anodes and support impressed current systems while also functioning as a structural mortar or concrete. The material can therefore be sprayed, cast, chased into bridge decks or applied within masonry joints, allowing it to integrate directly into repair and preservation strategies.

Laboratory testing demonstrated that the material could support protection current densities substantially higher than those typically required for reinforced concrete structures before acid generation became problematic.

This stability provides confidence for long-term use at lower operational current densities and supports the durability of the overall protection system.

Extending the life of existing structures

The technology has already been applied to several existing structures in both the United Kingdom and the United States.

Edinburgh parking structure

An underground parking structure in Edinburgh utilised a combination of repair strategies designed around condition assessment data and risk profiling.

Conductive geopolymer ICCP anodes were chased into parking decks and sprayed onto structural beams and walls, while galvanic zinc anodes activated by AACM mortars were incorporated into concrete repairs.

Additional areas were treated with surface-applied corrosion inhibitors before waterproofing systems were installed.

The entire structure was divided into 44 controllable cathodic protection zones, alongside additional monitoring zones used to assess corrosion inhibitor performance and future maintenance requirements.

The project aimed to extend the service life of the structure by at least 25 years while significantly reducing embodied carbon compared with demolition and reconstruction.

Masonry-clad steel frame buildings

The technology has also been adapted for transitional steel frame buildings dating from the early twentieth century.

These structures, commonly found in major cities, often suffer from corrosion of embedded steel sections concealed behind brick, stone or terracotta cladding. Corrosion products expand over time, causing cracking, displacement and eventual structural instability.

At a major property on Park Avenue in New York City, conductive anode systems were installed behind terracotta cladding to protect corroding steel elements at upper levels of the building.

The modular nature of the power, monitoring and control systems allows future expansion across additional areas of the structure as required.

Cathodic preservation in new construction

The article also highlights the advantages of incorporating cathodic protection during the construction phase itself.

In so-called cathodic preservation systems, modular anode units manufactured from sustainable AACM materials can be attached directly to reinforcement before concrete placement.

These units are interconnected through plug-and-play wiring systems linked to remote monitoring and control equipment. Concrete can then be cast in-situ or precast around the protected reinforcement.

Research suggests that incorporating cathodic protection at the point of construction can provide significantly enhanced durability and resilience throughout the structure’s intended design life.

Monitoring and service life management

A key aspect of the systems described is the integration of embedded corrosion monitoring technology.

Remote monitoring systems allow engineers and asset owners to track corrosion rates, assess protection performance and estimate future service life without requiring frequent site visits.

This continuous monitoring capability provides owners with measurable evidence of performance while also reducing maintenance-related travel and operational carbon impacts.

Conclusion

The development of sustainable conductive geopolymer materials represents a significant step towards decarbonising cathodic protection for the built environment.

By repurposing industrial waste streams into functional repair and protection materials, these systems offer the potential to reduce embodied carbon, preserve existing structures and support long-term infrastructure resilience.

The projects highlighted demonstrate that sustainable cathodic protection systems can provide effective corrosion control across a range of reinforced concrete and masonry applications while contributing to broader environmental and net-zero objectives.

Combined with integrated remote monitoring and service-life assessment technologies, such systems may form an increasingly important part of future asset management and structural preservation strategies.

Read our article ‘Decarbonization of Cathodic Protection for the Built Environment’, published by Materials Performance Magazine.

Making Bridges More Resilient from ICCP

Making Bridges More Resilient from ICCP

How do we futureproof historic infrastructure while meeting modern sustainability targets? A brilliant example can be found in north-east Scotland with the restoration of the Bervie Jubilee Bridge. Built in 1935, this iconic landmark carries the A92 from Aberdeen to Dundee. Faced with severe environmental degradation, Aberdeenshire Council opted for an innovative repair strategy that was well ahead of its time.

The Challenge: Severe Marine Corrosion

The bridge was suffering from severe chloride-accelerated corrosion on its reinforced concrete support beams and half-joint elements. This was caused by the harsh, circulating marine environment and water leakage, which led to:

  • Pitting of the structural steel reinforcement.

  • Cracking and spalling of the concrete cover.

  • A high risk of reduced load capacity, which could have forced a full bridge closure—severely impacting local trade and the economy.

To complicate matters, the bridge had to remain open to traffic during repairs. Access was a major hurdle, requiring the workforce to operate from a complex, full-height scaffolding platform built over the water.

The Solution: Impressed Current Cathodic Protection (ICCP)

Rather than opting for disruptive, traditional reconstruction, the council implemented an Impressed Current Cathodic Protection (ICCP) system alongside standard concrete repairs (compliant with BS EN 1504 and BS EN ISO 12696).

Because surface-mounted systems would ruin the bridge’s historic aesthetic, engineers used an innovative, internal approach:

  • Drilled-In Ceramic Anodes: Over 8,500 compact, star-shaped conductive ceramic anodes were inserted into the structure at variable depths to target complex 3D steel configurations.

  • Zonal Control: The installation was split into 20 distinct zones to separate the management of the beams and half-joints, all networked to a single communication point to minimise cabling.

  • Remote Performance Management: The system uses internet connectivity to track data from 80 monitoring locations weekly and monthly, assessing potential decay and corrosion rates.

The Results and ESG Benefits

Thirteen years after the installation was completed, data shows the ICCP system has successfully controlled and mitigated corrosion, keeping rates at negligible levels. The project stands as a textbook example of modern Environmental, Social, and Governance (ESG) policy in action:

Preserving Embodied Carbon: By repairing and protecting the existing asset rather than rebuilding it, the project achieved massive savings in embodied carbon and reduced greenhouse gas emissions.

  • Historic Preservation: Approved by Historic Scotland, the intrusive works left the bridge’s historic visual appearance completely unharmed.

  • Predictive Maintenance: Continuous remote data allows for proactive maintenance decisions, extending the service life of this vital asset indefinitely.

By embracing forward-thinking technology, Aberdeenshire Council successfully secured the future of a vital transport link while meeting the low-carbon, sustainable objectives outlined in today’s Construction Playbook.

Read our article ‘Making Bridges More Resilient from ICCP’, published by Concrete Magazine

Sustainability Champions: Case Study Compilation (Ciria)

Sustainability Champions: Case Study Compilation (Ciria)

Originally published on: https://www.ciria.org/CIRIA/Item_Detail.aspx?WebsiteKey=3f18c87a-d62b-4eca-8ef4-9b09309c1c91&iProductCode=SP172F&Category=FREEPUBS&OrderLineId=36943e20-3e9c-4580-a315-8760f75d94a1

How is the construction industry moving past corporate rhetoric and transforming sustainability into "business as usual"?A brilliant resource answering this is the Sustainability Champions: Case Studies Compilation (SP172F), published by CIRIA. This compilation profiles ten real-world initiatives across the UK, highlighting how forward-thinking individuals, collaborative teams, and pioneering technology are delivering tangible environmental, social, and financial benefits.

Locem corrosion protection

The report explores key themes like carbon reduction, circular economy frameworks, and smart technology. Here are five major takeaways from the case studies:

1. Scaling Corporate Change (Kier Group)

To implement an organisation-wide strategy across multiple sectors (highways, utilities, housing), Kier established cross-functional leadership forums and targeted working groups. By empowering individual business streams to develop localized plans, they successfully broke down traditional departmental silos and turned corporate sustainability goals into measurable everyday metrics.

2. Mining Capital Assets for Waste (Transport for London)

TfL spearheaded a proof-of-concept study focused on redundant power cables left behind in the London Underground network. Historically viewed as “waste,” the study shifted perceptions to view these assets as a “resource”. By calculating the perpetual structural risks, spatial constraints, and long-term costs of leaving redundant materials in situ, TfL highlighted how supply chains can close the material loop and recoup value through recycling.

3. Exploiting Material Exchange (Costain & National Highways)

In South Tyneside, two major road schemes situated just six miles apart capitalized on an infrastructure deficit and surplus. Despite a two-year gap between the project schedules, the teams collaborated to store and reuse 73,350 m³ of “waste” soil. This collaborative resource management saved up to £1 million in aggregate costs, cut haulage distances by 50,000 lorry miles, and prevented 90,000 kg of $\text{CO}_2\text{e}$ emissions.

4. Overcoming Specification Barriers for New Materials

A common blocker to sustainable innovation is a lack of industry standards, which leaves designers hesitant to adopt green alternatives. The compilation details how:

  • Alkali Activated Cements (AACMs): Collaborative efforts led to a Publicly Available Specification (PAS 8820:2016), accelerating market confidence and enabling low-carbon cements to move from university labs onto major sites like HS2.

  • Biodiversity Net Gain (BNG): The journey of BNG is tracked from a novel policy concept through to a structured British Standard, establishing consistent design frameworks well ahead of mandatory legislation.

5. Smart Resilience and Extending Life Cycles (C-Probe Systems)

Extending the lifespan of existing structures is a foundation of the circular economy. Through an academic partnership with Sheffield Hallam University, C-Probe developed low-carbon, geopolymer-based repair mortars utilizing industrial waste by-products. These alternative binders produce 80% less $\text{CO}_2$ than traditional Portland cement. When integrated with networked corrosion sensors and remote internet tracking, they provide asset owners with predictive, whole-life performance data to protect embedded carbon indefinitely.

The Blueprint for Industry Change

Ultimately, CIRIA’s compilation underscores that the green transition relies heavily on early stakeholder engagement and building cross-departmental bridges. When clients, suppliers, and engineers are equipped with the right data, guidance, and collaborative mindsets, the construction industry proves it can deliver scalable, low-carbon outcomes across projects of any size.

We have a featured case study in ‘Sustainability Champions: Case Study Compilation’, published by Ciria.

Achieving Sustainable Resilience in New Precast Concrete Structures (Buildoffsite/Ciria)

Achieving Sustainable Resilience in New Precast Concrete Structures (Buildoffsite/Ciria)

Originally published on: https://www.buildoffsite.com/publicationsguidance/publications/

Sustainable Resilience in Precast Structures

As climate change accelerates, rising temperatures and extreme weather are set to worsen the impact of structural corrosion, an issue that already costs trillions globally. We are proud to have sponsored the CIRIA X535 guide, which offers concrete solutions to this growing problem. The report provides vital signposts for designing more resilient precast concrete structures using sustainable materials that protect both your financial investment and the environment. If you are a contractor, engineer, or client looking to optimize whole-life asset value and reduce carbon impact, you can purchase your copy of this essential industry guide here.

We sponsored and contributed to ‘Achieving Sustainable Resilience in New Precast Concrete Structures’ (Buildoffsite/Ciria) – Purchase Here.

Linear Infrastructure Overbuild Guide (Buildoffsite/Ciria)

Linear Infrastructure Overbuild Guide (Buildoffsite/Ciria)

Originally published on: https://www.ciria.org/ItemDetail?iProductCode=X536&Category=BOOK&WebsiteKey=a90983f2-1465-42c2-b2f3-70ca25db674a

Linear Infrastructure Overbuild Guide

The CIRIA Linear Infrastructure Overbuild Guide (X536) is a practical, collaborative roadmap designed to unlock the massive development potential of urban “airspace”, specifically the areas directly above active railway lines and major roadways. Inspired by research showing that building over London’s rail tracks alone could yield up to 250,000 new homes, this guide addresses the extreme logistical and structural complexities that have traditionally made these air-rights projects high-risk. By focusing heavily on Modern Methods of Construction (MMC) and offsite manufacturing, the publication demonstrates how lightweight, prefabricated modular systems can minimize community disruption, shorten construction windows, and significantly reduce safety risks over live transportation corridors.

Authored by industry experts from the Buildoffsite Rail Hub, the 82-page guide serves as an essential resource for urban developers, structural engineers, and transport authorities. It bridges the gap between complex engineering requirements, such as managing multi-layered stakeholder agreements and building structural podiums, and commercial viability. Ultimately, the guide provides strategic frameworks to lower the entry barrier for air-rights developments, making it easier for mid-sized developers and offsite specialists to confidently plan, fund, and execute high-density, sustainable urban overbuild projects.

Purchase the ‘Linear Infrastructure Overbuild Guide’ here.

Bridges and Viaducts DfMA Guide (Buildoffsite / Ciria)

Bridges and Viaducts DfMA Guide (Buildoffsite / Ciria)

Originally published on: https://www.buildoffsite.com/publicationsguidance/publications/

Major bridge and viaduct projects are under increasing pressure to deliver more — faster construction, lower costs, improved sustainability, reduced disruption and infrastructure that lasts longer. A new industry guide explores how combining Design for Manufacture and Assembly (DfMA) with Offsite Construction can help achieve all of these goals.

Our team was proud to contribute to this guide, which examines how these approaches work together across the entire lifecycle of bridge and viaduct infrastructure — from early design and procurement through to assembly, operation and long-term maintenance.

Bridges and Viaduct DfMA Guide

Why DfMA and Offsite Construction Matter

Traditionally, large infrastructure projects have been heavily dependent on extensive on-site construction. The guide highlights how Offsite Construction changes this model by shifting much of the manufacturing and assembly process into controlled factory environments.

This enables:

  • Greater precision and quality control
  • Faster assembly on site
  • Reduced disruption to surrounding communities
  • Improved safety and productivity
  • More efficient long-term maintenance

By designing components specifically for manufacture and assembly, project teams can also reduce complexity, streamline logistics and minimise waste throughout the delivery process.

Building for the Full Lifecycle

One of the key themes explored in the guide is designing infrastructure with longevity and adaptability in mind.

Offsite-manufactured components can incorporate additional built-in functionality, including:

  • Utility services such as electricity, water and wastewater systems
  • Embedded monitoring technologies
  • Future-proofed maintenance access
  • Enhanced durability and lifecycle performance

This approach supports smarter asset management and more efficient maintenance strategies over the lifetime of the structure.

Smarter Design Through Collaboration

The guide also demonstrates how closer collaboration between designers, manufacturers, suppliers and clients encourages innovation from the earliest project stages.

Through modularisation and mass customisation, teams can develop product families that meet strict requirements around:

  • Cost efficiency
  • Structural performance
  • Safety
  • Aesthetics
  • Logistics and transportation
  • Assembly sequencing

Importantly, this collaborative approach helps projects apply Lean principles more effectively, reducing waste, improving predictability and supporting better programme outcomes.

Reducing Disruption and Improving Safety

For bridge and viaduct projects spanning existing roads, railways or waterways, minimising disruption is critical.

Because many components are manufactured and pre-assembled offsite to precise tolerances, on-site installation becomes significantly faster and more controlled. This reduces:

  • Traffic disruption
  • Construction risk
  • Site congestion
  • Environmental impact on local communities

The guide also highlights how controlled manufacturing environments create better opportunities for continuous improvement, long-term learning and safer working practices.

Better Infrastructure, Better Outcomes

Ultimately, the guide demonstrates that designing for manufacture and assembly is about much more than construction efficiency. It represents a more integrated, forward-thinking approach to infrastructure delivery, one that delivers benefits for funders, contractors, local communities and end users alike.

By reducing component counts, increasing functionality and simplifying logistics, DfMA and Offsite Construction can help create infrastructure that is more resilient, more efficient and better suited to future demands.

Read our contribution to the ‘Bridges and Viaducts DfMA Guide’ – Buildoffsite and Ciria publication.

Predicting Service Life from Site-Accessed Corrosion Rate Data

Predicting Service Life from Site-Accessed Corrosion Rate Data

Infrastructure assets are expected to perform safely and efficiently for decades, often in highly aggressive environments. Yet corrosion remains one of the biggest threats to the long-term durability of reinforced concrete and masonry structures.

Our paper, Predicting service life from site-accessed corrosion rate data, explores how long-term corrosion monitoring can provide a more accurate and practical understanding of structural deterioration, enabling owners and engineers to make better-informed decisions around maintenance, repair and life extension.

The paper draws on more than 20 years of data collected from over 60 structures across the UK and internationally, including bridges, tunnels, marine structures, car parks and historic buildings.

Moving Beyond Theoretical Modelling

Traditional service life prediction models often rely heavily on assumptions and theoretical deterioration rates. While these models remain valuable, our work demonstrates the benefits of combining them with continuous, real-world monitoring data.

By embedding corrosion rate probes directly within structures, engineers can:

  • Continuously assess corrosion activity over time
  • Identify when deterioration transitions from initiation to propagation
  • Track the effectiveness of repair and protection strategies
  • Improve confidence in service life predictions
  • Support proactive maintenance planning

Rather than relying solely on periodic inspections or isolated measurements, this approach creates a continuously evolving picture of structural health.

Understanding Corrosion in Real Structures

The paper examines the development and deployment of embedded corrosion monitoring systems installed across a wide range of environments and asset types.

These monitoring systems have been used to assess:

  • Reinforced concrete bridges
  • Marine jetties
  • Car parks
  • Tunnels
  • Historic masonry structures
  • Post-tensioned and pre-stressed systems

In many cases, probes have collected data remotely over periods spanning many years, enabling engineers to understand how corrosion behaviour changes over time under real environmental conditions.

From Monitoring to Service Life Prediction

A key focus of the paper is how corrosion data can be used to develop more meaningful service life predictions.

Rather than assessing a single corrosion rate measurement in isolation, the paper demonstrates how accumulated corrosion penetration data (Pcorr) can be used alongside established service life models, including the Tuutti model, to:

  • Predict residual service life
  • Identify optimum intervention points
  • Evaluate long-term deterioration trends
  • Quantify the impact of mitigation measures

This provides asset owners with a far more practical basis for planning maintenance and investment strategies.

Evaluating Repair and Protection Strategies

The paper also explores how corrosion monitoring can be used to assess the effectiveness of intervention methods in real time.

Mitigation measures assessed include:

  • Surface-applied corrosion inhibitors
  • Cathodic protection systems
  • Waterproofing solutions
  • Different concrete repair materials and cover systems

Long-term monitoring demonstrated significant differences in performance between repair strategies, including examples where service life extensions exceeded 50 years when appropriate repair materials were selected.

Supporting Smarter Asset Management

Ultimately, the paper highlights how embedded corrosion monitoring can support a more proactive and data-driven approach to infrastructure management.

By combining continuous monitoring with established service life modelling, engineers and asset owners can:

  • Better understand deterioration mechanisms
  • Reduce uncertainty in maintenance planning
  • Optimise intervention timing
  • Improve whole-life performance
  • Extend the serviceable life of critical infrastructure

As infrastructure networks continue to age, approaches that improve long-term decision-making and reduce lifecycle risk will become increasingly important.

Read ‘Predicting Service Life from Site-Accessed Corrosion Rate Data’ published by Institute of Civil Engineers (ICE) Academic Journal

Optimised Cathodic Protection Design for Maximum Bond Performance in Reinforced Concrete

Optimised Cathodic Protection Design for Maximum Bond Performance in Reinforced Concrete

Reinforced concrete structures in marine and chloride-rich environments face a persistent challenge: corrosion of embedded steel reinforcement. Left untreated, corrosion can reduce structural performance, shorten service life, and lead to costly repairs or premature replacement.

That’s why we were pleased to contribute to the research paper:

“Optimised cathodic protection design for maximum bond performance in reinforced concrete” by Fin O’Flaherty, Chinh Van Nguyen, Paul Lambert, Pal Mangat, and Graeme Jones.

The study explores how impressed current cathodic protection (ICCP) can be optimised to maximise long-term durability while preserving the critical bond between steel reinforcement and concrete.

Why Bond Performance Matters

In reinforced concrete, the bond between steel and concrete is essential. It allows the two materials to work together structurally. If corrosion progresses unchecked, that bond can eventually deteriorate, reducing structural reliability and service life.

Cathodic protection is already recognised as one of the most effective methods of controlling reinforcement corrosion. However, there has historically been concern that excessive cathodic protection current densities could negatively affect the steel-to-concrete bond over long periods of time.

This research set out to answer an important practical question:

Can ICCP systems be designed to provide long-term corrosion protection without compromising bond performance?

What the Research Investigated

The study examined 16 reinforced concrete pull-out specimens with varying levels of pre-corrosion:

  • 0% corrosion (control)
  • 1% corrosion
  • 2% corrosion
  • 5% corrosion

Different ICCP current densities were then applied, including levels significantly higher than those normally used in practice. These accelerated conditions allowed the team to simulate decades of long-term performance within a practical laboratory timeframe.

The researchers analysed:

  • Bond strength between steel and concrete
  • Total electrical charge applied over time
  • Chloride migration away from reinforcement
  • Long-term implications for design life

Key Findings

1. ICCP Can Be Optimised Without Reducing Design Bond Strength

2. Moderate Corrosion Can Temporarily Increase Bond

3. ICCP Helps Reduce Chloride Concentration Around Steel


Why This Matters for Infrastructure Owners

For bridge owners, marine asset operators, and infrastructure managers, the findings support a more performance-based approach to cathodic protection design.

Rather than simply applying higher currents for additional protection, the research demonstrates the value of:

  • Optimised current density selection
  • Long-term total charge assessment
  • Balancing durability with structural performance
  • Extending asset life while minimising unintended side effects

The work also supports more sustainable infrastructure management by helping existing reinforced concrete assets remain in service for longer.

Industry Relevance

The findings are particularly relevant for:

  • Coastal bridges
  • Marine structures
  • Jetties and ports
  • Sea defences
  • Parking structures
  • Chloride-contaminated reinforced concrete assets

As infrastructure owners increasingly focus on whole-life performance and resilience, optimised ICCP design becomes an important tool in extending operational life safely and efficiently.

Read ‘Optimised Cathodic Protection Design for Maximum Bond Performance in Reinforced Concrete’, published by Materials and Corrosion Academic Journal

Get in touch with any questions, queries or potential projects.