Everything You Need To Know About Concrete Corrosion Mapping

September 20, 2023
Concrete is a widely used construction material known for its durability and strength. However, over time, it can deteriorate due to various factors, one of the most common being corrosion.

Concrete corrosion, also known as rebar corrosion, can lead to structural issues and pose safety risks. To prevent these problems and ensure the longevity of concrete structures, it's crucial to understand and implement concrete corrosion detection. In this comprehensive guide, we'll cover everything you need to know about this essential process.

What is concrete corrosion?

Concrete corrosion occurs when the reinforcing steel within concrete structures starts to deteriorate due to chemical reactions or environmental factors. The most common form of corrosion in concrete is caused by the penetration of chloride ions or carbonation into the concrete, which can lead to the rusting of the embedded steel. This corrosion can weaken the structure, reduce its load-bearing capacity, and ultimately lead to structural failure if left unchecked.

Concrete corrosion pictured from the underside of a suspended slab

What type of structures can be affected by concrete corrosion?

Concrete corrosion can affect a wide range of structures, especially those that are exposed to environmental or chemical factors that promote deterioration. Common structures that are susceptible to concrete corrosion include:

- Parking Garages
- Bridges
- Highway Overpasses
- Tunnels
- Dams
- Swimming Pools
- Sewage and Water Treatment Plants
- Industrial Facilities
- Concrete Buildings
- Oil and Gas Mining Facilities

Why is concrete corrosion mapping important?

‍Concrete corrosion mapping is crucial for several reasons:

Prevents Structural Damage
Corrosion can weaken the structural integrity of concrete, leading to cracks, spalling, and even disastrous collapses. By identifying areas of corrosion through mapping, you can take proactive measures to repair and protect the structure before significant damage occurs.

Extends Lifespan
Regular corrosion mapping allows you to monitor the condition of your concrete structures and implement preventive maintenance measures. This can significantly extend the lifespan of the concrete, saving you time and money in the long run.

Ensures Safety
Corrosion in concrete can compromise the safety of a building or infrastructure. By mapping and addressing corrosion issues proactively, you can ensure the safety of occupants and prevent accidents.

Heavily corroded concrete pillar in an underground parking garage

How does concrete corrosion mapping work?

Concrete corrosion mapping involves several key steps:

1. Visual Inspection
A visual inspection of the concrete structure is the first step. This includes assessing the surface for signs of corrosion such as cracks, spalling, discoloration, and rust stains. Visual inspection helps identify areas that require further investigation.

2. Non-Destructive Testing (NDT)
Non-destructive testing techniques, such as Xradar™, ground-penetrating radar, ultrasonic pulse echo, and half-cell potential, are used to assess the condition of the concrete and the extent of corrosion. These methods provide valuable data without damaging the structure.

3. Data Analysis
The data collected through NDT is analyzed to create a corrosion map of the concrete structure. This map highlights areas with high corrosion risk, allowing for targeted repair and maintenance efforts.

4. Repair and Protection
Based on the corrosion map, appropriate repair and protection measures are implemented. This may include removing and replacing corroded concrete, applying corrosion-resistant coatings, or installing cathodic protection systems.

Xradar corrosion map of upper parkade with results and core test points superimposed

Preventative measures for concrete corrosion

Concrete corrosion mapping is essential, but preventive measures can also help reduce the risk of corrosion. Here are a few precautionary tactics:

Use Corrosion-Resistant Materials
When constructing concrete structures, consider using corrosion-resistant materials, such as stainless steel rebar, or applying corrosion-inhibiting admixtures.

Proper Maintenance
Regular maintenance, including cleaning, sealing, and patching, can help protect concrete surfaces from corrosive elements.

Cathodic Protection
Cathodic protection systems can be installed to control corrosion by applying an electric current to the reinforcing steel, preventing it from rusting.

Monitoring and Inspection
Schedule regular inspections of your concrete structures with reputable concrete specialists such as Xradar. This will help identify corrosion early so you can take appropriate action.

Putting it all together

Concrete corrosion mapping is a crucial process for a range of organizations and professionals involved in the construction, maintenance, and inspection of concrete structures. By understanding the causes and consequences of corrosion, implementing preventive measures, and conducting regular mapping and inspections, you can protect your investments and maintain the integrity of your concrete infrastructure for years to come.

Don't wait until corrosion becomes a major problem. Get in touch with us today to schedule a comprehensive concrete corrosion survey of your structure.