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Comparing the Benefits of In Situ Concrete Mattresses and Rock Armour
When it comes to protecting marine infrastructure from port scour, choosing the right solution is critical. Scour protection is essential to maintain the integrity of structures such as jetties, quay walls, and other marine installations. Traditionally, rock armour has been used to prevent seabed erosion. However, in recent years, in situ concrete mattresses have become the preferred option for many projects due to their numerous advantages over rock armour.
At Proserve Ltd, we have decades of experience in designing and supporting the install of concrete mattress systems for scour protection. Below, we explore why in situ concrete mattresses are increasingly being chosen as the superior solution to combat port scour.
1. Comprehensive Coverage and Flexibility
In situ concrete mattresses offer unmatched flexibility compared to traditional rock armour. As they are cast directly onto the seabed, these mattresses conform to the contours of the seabed, providing comprehensive scour protection. The formwork for concrete mattresses is installed on-site, and once the concrete is pumped in, it forms a seamless apron that adapts to the seabed’s undulations.
This flexibility allows in situ concrete mattresses to provide more reliable and extensive coverage, sealing tightly against structures and interlocking with adjacent panels. In contrast, rock armour is installed in layers to provide the same protection. Concrete mattress can be up to seven times thinner than rock armour due to its sealed installation. Rock armour by comparison requires significantly more deadweight to withstand the same velocities.
In situ concrete mattresses flexibility is exemplified at jetty structures. The formwork can be placed under the deck and provides a sand tight seal around piles. This case study from the Al Faw Grand Port shows how a change of design had a significant cost, carbon and construction time savings.
2. Significant Cost Savings with In Situ Concrete Mattresses
One of the biggest advantages of in situ concrete mattresses over traditional rock armour is the cost savings they offer. Concrete mattresses can be up to seven times thinner than rock armour while still providing superior scour protection. This reduction in material results in lower transportation costs and easier installation.
Traditional rock armour requires large quantities of heavy materials to be sourced, transported, and placed. Often, this rock has to be moved over long distances, increasing both cost and environmental impact. In contrast, the formwork for concrete mattresses can be shipped via pallets, and the concrete can be pumped directly into place, significantly reducing logistics costs.
At Proserve Ltd, we specialise in the efficient deployment of concrete mattress systems, allowing our clients to benefit from these cost savings while ensuring top-tier protection against port scour.
The cost savings of concrete mattress vs rock armour are not limited to direct installation costs, but also larger efficiencies form new construction of ports and port deepening.
Due to the reduced thickness required for in situ concrete mattress and the high velocities it can withstand its being increasingly used for deepening exiting berths to maximise the full extent of the wall.
When designing new port walls, the same principle can also be deployed saving significant scour protection and wall height costs.
3. Faster and Less Disruptive Installation
Speed and minimal disruption are crucial for any scour protection project, especially in busy port environments. Installing traditional rock armour can be time-consuming, requiring the use of heavy marine equipment and large-scale operations. In comparison, in situ concrete mattresses can be installed more quickly and with significantly less disruption.
At Proserve Ltd, we pump the concrete directly from the quayside into the formwork, minimising the need for extensive marine plant and diver operations. This process significantly reduces installation time and ensures that port operations can continue with minimal downtime. By choosing in situ concrete mattresses, you can achieve faster project completion and a smoother construction process.
4. Durability and Long-Term Performance
In situ concrete mattresses offer exceptional durability in harsh marine environments. Once the concrete sets, it forms a highly resistant and abrasion-proof surface that can withstand the constant exposure to saltwater, strong currents, and vessel wash. This is crucial for maintaining long-term protection against port scour.
Unlike rock armour, which can be displaced over time and requires regular maintenance, concrete mattresses form a continuous and stable layer that resists the forces of erosion. This reduced need for maintenance makes concrete mattresses a cost-effective solution for long-term scour protection.
With over 40 years of experience, Proserve Ltd has successfully deployed concrete mattresses in ports and marine environments around the world, providing durable solutions that last for decades.
5. Material and Carbon Savings in Scour Protection
In today’s marine construction industry, reducing material usage and carbon emissions is a key consideration. In situ concrete mattresses provide a more efficient solution for scour protection compared to traditional rock armour. By requiring less material and transportation, concrete mattresses significantly reduce the carbon footprint associated with construction.
Concrete mattress systems can be designed to achieve the necessary scour protection with thinner, more adaptable layers, which leads to further material savings. In contrast, large-scale rock armour installations often require considerable volumes of material and heavy transport, increasing both costs and carbon emissions.
Conclusion: The Future of Scour Protection in Ports
As the demands on port and marine infrastructure grow, the need for effective and efficient scour protection is more important than ever. In situ concrete mattresses are increasingly being used over traditional rock armour due to their superior flexibility, significant cost savings, faster installation, enhanced durability, and environmental benefits.
At Proserve Ltd, we have the expertise and experience to deliver bespoke concrete mattress solutions for ports, harbours, and marine structures worldwide. With a focus on innovation and sustainability, we ensure that your infrastructure is fully protected against port scour for years to come.
For more information on how Proserve Ltd can help with your scour protection needs, contact us today.
