Maccaferri commitment in hydraulics started back in the 19th century.
For over 140 years, we have developed solutions that enhance river ecosystem resilience including the social ability to recover quickly from catastrophic events. We did it from the very first application that we carried out in River Reno, in Italy.
Reno Mattress, one of our most common solution, was named after this first intervention. Today the term Reno Mattress is synonymous with hydraulic works and erosion protection projects worldwide.
Reno Mattresses are units manufactured from double twisted hexagonal woven steel wire mesh 6×8 type, made of heavily galvanised wire. Reno mattresses are divided into uniformly partitioned cells by internal diaphragms positioned at 1-meter lateral centres; the diaphragms are created by an upright double-mesh fold in the base panel, which improves diaphragm stability during filling operations.
Some historical landmarks on the development of Reno mattresses:
- A first ancestor of the modern Reno mattress developed by Maccaferri was the so called «Mantellata Volga», mentioned in historical books dated in early 1910’s, over 110 years ago;
- It is years later, in the early 60s, when Maccaferri develops the Reno mattress as industrially manufactured product. Since their first applications, mattresses find an interest for being flexible and monolithic structures;
- However, it is only in 1984 that mattresses become an engineered system, after an experimental study by CSU. Standard Mattresses at that time had a single diaphragm partition, connected to the base panel by a spiral wire;
- A few years later, in 1990, Maccaferri decides to industrially improve the manufacture of mattresses by pleating the base mesh panel in a way to form the vertical partition, resulting in a double diaphragm;
- For about 2 decades the new mattress (so called Castoro) is designed still using the allowable resistance factors in use for standard single diaphragm mattresses, tested in 1984, on the safe side.
Maccaferri Innovation Center
Maccaferri is strongly focused on innovation. At the end of 2014, we created a centre of excellence entirely dedicated to Research and Development: Maccaferri Innovation Center S.r.l.
This is the place where we develop the next generation of Maccaferri products and also to cultivate the best innovation and support to our clients.
Here we tested and launched one of our latest products: Reno Mattress Plus with X-Ties.
Reno Mattress Plus with X-Ties
A new research in 2018-2020 using Castoro mattresses allowed to confirm the better performance of the «castoro type» versus the standard type, and to introduce a new correlation with factors not considered in the past studies. This led to the optimization of the limit performance of the new mattress.
This new and more modern approach based on a standard method for testing erosion systems (ASTM D6460) allowed to upgrade the concept of standard mattresses to a new erosion protection system: the Reno Mattress Plus with X-Ties.
The Reno Mattress Plus with X-Ties has basically 3 main improvements compared to conventional mattresses:
- the pleating of the mesh, making the partitions much more robust with the double mesh;
- the innovative and much more durable new polymer coating (Polimac), making the wire more resistant to abrasive effect of sediments carried by the flow, a higher UV resistance to high temperatures as well as a much lower embrittlement temperature;
- the X-Ties, to connect the lid firmly and securely to the bottom of the mattress. X-Ties are free standing tools, and this makes them particularly easy to install. They considerably improve the structural performance of the mattress against the flow, preventing the movement of stones.
The PoliMac coating
Another important innovation coming with Reno Mattress Plus with X-Ties is the PoliMac coating: a high performing protection to extend the durability of the wire much beyond any other alternative.
PoliMac offers better resistance to abrasion, outstanding chemical resistance, excellent performance both in cold climates (endurance to embrittlement) and in hot climates (loss of initial property under UV rays exposure).
Some of the results PoliMac showed during our tests, compared to common wires:
- x10 more abrasion resistance
- 35% more resistant to UV rays
- 23% more hardness
Benefits of Reno Mattress Plus with X-Ties
Reno Mattresses Plus have 3 important advantages:
- material reduction: as with their optimized design, volumes of rockfill are significantly reduced;
- environmental burden reduction: as a consequence, their reduced volume of material required, drastically reduces the carbon footprint, resulting in a lesser environmental impact on the surrounding environment;
- installation time reduction: less installation time results in a lesser overall cost for the structure, bringing a lower financial effort to the surrounding communities.
For what concern Material Reduction, let’s consider three options when we deal with the design of a riverbank protection: loose stone (rip-rap), Standard Mattress, and Reno Mattress Plus.
We already have a significant reduction going from loose stone to standard mattress, thanks to the benefit that the confinement of the stone brings in.
The introduction of the X-tie gives to Reno Mattress Plus more performance that dramatically reduce the thickness of the bank protection.
The second advantage making our Reno Mattress Plus an attractive alternative is the environmental burden reduction compared to traditional systems. In the construction of a riverbank protection, Reno Mattress Plus generate a very low CO2 emission, compared to RIP RAP or even standard mattresses in high flow regimes. The values shown have been obtained from EPD which is an Environmental Product Declaration.
An Environmental Product Declaration (EPD) is defined by ISO 14025 (EN 15804) and it “quantifies environmental information on the life cycle of a product to enable comparisons between products fulfilling the same function. The EPD methodology is based on the Life Cycle Assessment (LCA) tool that follows ISO 14040.
According to the values provided by the EPD, by increasing the shear stress, hence the flow regime, the thickness of the protection, as well as the CO2 emissions, increase.
Design the change
Reno Mattress Plus is part of a wider initiatives that is named Design The Change. We want to boost the use of sustainable product in civil engineering because we firmly believe that this brings value to all the stakeholders in the industry.
It is worth to mention that Reno Mattress Plus coated with PoliMac® decreases CO2 emissions of 82% compared to Rip-rap solution; in addition, Reno Mattress Plus with X-Ties further reduce the environmental burden in comparison to Standard Mattresses: less stones means less CO2 emissions, less truck movements, and so on.
An additional benefit of Reno Mattress Plus: the interstitial space between stones is a preferred habitat for many species enhancing the biological diversity. Sea stars and various types of fishes, even endangered species like seahorses, find in Reno Mattresses a shelter.
Installation reduction time
Reno Mattresses Plus speed up onsite operations for two main reasons:
- the self-standing tie, developed to make installation easier and to improve structural performance of the mattress;
- the robust double diaphragm, enabling fast installation especially on steep slopes and minimising installation inaccuracies.
Do you want to know more about Reno Mattress Plus with X-Ties?