Protecting your marine concrete structures from corrosion? Wanting to reduce high maintenance costs?
If you are an engineer, developer or asset manager, don’t let your concrete structures suffer the same fate as many other structures in and around the harsh marine environment.
Read on to learn:
- How concrete is not unconquerable on its own – and how you can enhance/protect it, especially around the marine environment
- The effects of moisture and contaminant migration through concrete – and how to stop it
- How to reduce your maintenance costs – and how $1 spent in construction saves $125 in maintenance
Concrete is not unconquerable on its own – Here’s how you can protect it
Many people run into the problem when dealing with concrete, thinking that concrete is a non-destructive material and doesn’t do anything to protect it from deterioration and its effects over time.
Concrete is naturally durable – but not entirely. All concrete is slightly porous, due to micro-pores formed during curing. This means that moisture and moisture-borne contaminants can enter the concrete.
Contaminants include chlorides, nitrates, and other reactive substances that reduce the concrete’s natural durability and accelerate deterioration.
- Download a case study: Dublin Port Berth 34
Marine concrete is especially at risk.
Seawater contains high concentrations of chlorides, among other constituents. Due to high ambient moisture levels, these contaminants are easily carried into the concrete and attack both the concrete and the reinforcing steel, creating a cycle of deterioration.
How do you protect your concrete?
Coatings are not enough. They are easily abraded, do not guarantee complete coverage, and do not prevent moisture from moving between uncoated abutting surfaces.
Crystalline technology is inadequate. Crystalline formations within the concrete are a one-shot application, are susceptible to slight structural movement, and are not responsive to ambient moisture fluctuations.
So if coatings and crystalline technology are not the answer – how do you protect your concrete?
By using an advanced, colloidal silica hydrogel concrete durability and waterproofing admixture.
A C-S-H hydrogel can be produced within the concrete by applying nano-particle colloidal silica. This reacts with free moisture and calcium within the concrete. The resulting ‘gel’ formation immobilises moisture, preventing the entry and movement of contaminants carried by that moisture (and moisture vapour).
Why use a hydrogel admixture?
- Firstly, the concrete delivered to your site is already waterproofed throughout the mix. No need to wait for moisture ingress to activate it like other products.
- Secondly, hydration improves, reducing shrinkage; compressive and flexural strengths are enhanced, improving long-term durability.
- Then there’s improved workability, ease of placement, and environmental safety.
- And the steel reinforcement is protected from day one.
Even The Roman Empire Utilised Silica
Roman concrete used ‘pozzolana’ wherever possible. This was volcanic dust with high alumina and silica content. This silica content contributed to the concrete becoming resistant to cracking and robust in seawater.
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Moisture migration is killing your concrete
Again, any concrete around the marine environment is especially at risk. Seawater contains high concentrations of chlorides, among other constituents. Due to high ambient moisture levels, these contaminants are easily carried into the concrete and attack both the concrete and the reinforcing steel.
Concrete within the splash zone is especially prone to early deterioration. This is due to the aggressive movement of moisture and rapidly varying moisture levels.
The effects of moisture and contaminant migration through concrete.
Moisture is the vehicle for contaminants. Reactants such as chloride and nitrate ions are carried in solution by moisture and moisture vapour. These can react with the concrete itself or reach the reinforcing steel, causing corrosion.
Unwanted concrete reactions and steel corrosion cause significant cracking, opening the way to further contamination and, in turn, a cycle of deterioration.
How to stop moisture from slowly but surely destroying your concrete?
Immobilise the moisture!
A specialised catalytic silica treatment can be applied, inducing a hydrogel within the concrete’s porosity. This hydrogel binds free moisture within the concrete, preventing the ingress or movement of moisture-borne contaminants.
- Read more about conquering chlorides in concrete
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Save $125 in maintenance costs with $1 spent at construction
$1 spent in construction saves $125
Wolter Reinold de Sitter, a part-time professor of structural concrete design at Eindhoven University of Technology, proposed a Law of Fives for structural concrete maintenance.
There are various English versions extant, but fundamentally, the law reads as follows:
- The life of a concrete structure, with respect to durability, can be divided into four phases:
- Phase A: Design, construction and concrete curing
- Phase B: Corrosion initiation processes are underway, but the propagation of damage has not yet begun
- Phase C: Propagating deterioration has just begun
- Phase D: Propagation of corrosion is advanced, with extensive damage manifesting
- $1 extra spent at Phase A is equivalent to saving $5 at Phase B, $25 at Phase C, or $125 at Phase D.
Now think about that – a little extra investment during the design, construction, and curing phases will reduce long-term expenses.
So, what can you do to reduce your maintenance costs?
To arrest the deterioration cycle, ACT EARLY!
Concrete hydrogels, introduced as a catalytic silica admixture, will prevent the movement or ingress of moisture-borne contamination. This arrests the deterioration cycle.
By arresting and delaying this deterioration, the service life of the structure will be increased, and overall maintenance costs will be significantly reduced.
- Read more about protecting new concrete
In Conclusion
So a quick recap on protecting your marine concrete structures and reducing your maintenance costs:
- Concrete is not fail-safe on its own.
- You need to stop moisture and contaminant migration through concrete.
- You should be protecting it from within by using an advanced colloidal silica hydrogel admixture.
- By adding an admixture at the construction stage, you can save you approx. $125 in maintenance.
Intrigued? Faced with concrete asset maintenance challenges? We’d like to hear from you.
More learnings with our on-demand webinar “The Challenge of Marine Concrete“.
