Coastal areas are a paradise for many, but they’re no friend to reinforced concrete structures. The harsh marine environment, laden with salt-laden air and high humidity, accelerates the natural corrosion process. This corrosion can mean reduced lifespan, costly repairs, and even structural failure for infrastructure such as bridges, seawalls, and piers. Enter cathodic protection (CP)—a proven method to combat corrosion and preserve the integrity of structures exposed to these harsh conditions.
At South-East Scanning, we understand the unique challenges of coastal environments and how cathodic protection can serve as a frontline defence against the relentless assault of corrosion. Let’s explore why CP is essential for coastal structures and how it works to protect them for the long haul.
Why Coastal Structures Are at Greater Risk
In coastal regions, structures are constantly exposed to saltwater and salty air, which are highly conductive and expedite corrosion. When saltwater penetrates concrete, it reaches the steel reinforcement (rebar) inside, triggering a chemical reaction that causes the steel to rust and expand. This expansion leads to cracking, spalling and ultimately, a weakening of the structure.
This process can occur much faster than in inland environments for structures like bridges and retaining walls in areas such as Brisbane and the Sunshine Coast. Add to this the frequent wet-dry cycles from tides or rainfall, and the risk of corrosion multiplies.
How Cathodic Protection Works
Cathodic protection is an ingenious solution to stop corrosion before it causes damage. It works by making the rebar in the concrete a “cathode,” halting the electrochemical reactions that lead to rusting. There are two primary types of cathodic protection systems:
1. Sacrificial Anode Systems
These systems use a more reactive metal, such as zinc or magnesium, that corrodes in place of the steel rebar, protecting it from deterioration.
2. Impressed Current Systems
For larger structures in these highly corrosive environments, impressed current cathodic protection (ICCP) uses an external power source to provide a steady flow of protective electrical current to the rebar, preventing corrosion regardless of environmental conditions.
Both systems are highly effective, and their choice depends on factors such as the structure’s size, location, and environmental exposure.
Why Coastal Structures Need Cathodic Protection Now
As infrastructure ages, the need for cathodic protection becomes more urgent. Coastal areas are expanding, with new developments and older structures bearing the brunt of harsher conditions than ever before. Without intervention, these structures face accelerated deterioration, leading to safety hazards and increased repair costs.
Cathodic protection stops corrosion and significantly extends the life of coastal infrastructure. This means fewer repairs, less downtime, and greater safety for the people and industries that rely on these structures.
How South-East Scanning Can Help
At South-East Scanning, we specialise in assessing, designing, and supporting cathodic protection systems tailored to the unique needs of coastal structures. Using advanced technology like GPR, we can determine concrete conditions, locate reinforcement, and identify areas at high risk for corrosion. With this data, we work alongside engineers to implement effective CP solutions that protect your investment and ensure long-term durability.
Conclusion
Corrosion is an unavoidable challenge in coastal areas, but it doesn’t have to be a problem. Cathodic protection offers a reliable, cost-effective way to safeguard reinforced concrete structures from the damaging effects of the marine environment. With the right system in place, coastal structures can endure harsh conditions, ensuring safety and longevity for decades.
Is your coastal structure sufficiently protected? Contact South-East Scanning to learn how we can help implement cathodic protection solutions tailored to your needs. Let’s protect your investment and the environment together!
Both systems are highly effective, and their choice depends on factors such as the structure’s size, location, and environmental exposure.
