Nice Eco Stadium
ADIM Côte d'Azur
Wilmotte & Associés SA
• Serge Ferrari composite membrane :
Précontraint 1202 S2
> 12,000m² for roof
> 1,600 m2 for “Allianz Riviera” naming
> 60 panels (rectangular and trapezoidal)
> 60 m long x 10 m wide
A model of eco-design and eco-construction, Allianz Riviera is one of the first eco-stadiums in the world to be located in an eco-area. A positive energy structure, the Nice stadium meets the prime requirement of integrating into the Eco-valley landscape of the Var Plain.
The facility has benefitted from a green procurement policy aimed at reducing its environmental footprint to a minimum. Contractors were therefore selected based on a responsible approach, implementing more specifically an environmental impact assessment for their products (LCA) and/or their capacity for proposing innovative solutions in terms of recyclability. Eco-designed and 100% recycled – using Ferrari Texyloop® technology – Précontraint 1202 S2 composite membrane met these criteria to perfection and now boasts a stadium roof application.
Manufactured by the Serge Ferrari Group in Rhône-Alpes, France, this translucent membrane – insensible to UV rays – has been implemented in the roof’s 7,500 m2 of solar panels and its cantilevered extension. “Lightweight and aesthetic, it hugs the undulating curves of the steel/timber composite roof frame waveforms and covers the main stands, small stands and bends respectively. It ensures spectator comfort by transmitting diffuse natural light and protection in bad weather”, declares Marco Punzi, agency Wilmotte & Associés SA project director.
“From design to installation, the membrane required close technical coordination with the roof erection contractor to ensure optimum control of the loads transferred to the composite roof frame” explains Yannick Faurant, ACS Production’s general manager.
The Précontraint 1202 S2 membrane was installed by double lacing and fixed to tubes incorporated in the steel roof members. The waterproof rain guides conveying rainwater to the gutters were hot-welded on site. “Allianz Riviera” lettering… welded using a press to a Serge Ferrari double membrane, these semi-permanently positioned letters should disappear for the Euro 2016 football championship.
“Working more than 40 metres up, we focused our full attention on safety by developing specific temporary equipment including “flying walkways”, which allowed us to move across the roof frame as the work progressed” concludes Yannick Faurant.
Ensuring additional acoustic absorption of very high frequencies, the Serge Ferrari membrane also contributes to controlling sound reverberation at the very heart of the sports facility. “It forms an integral part of the acoustic control strategy by complementing the other materials” notes Laurent Egarnès, project manager for consulting engineer Lamoureux Acoustics.
Evaluation of the potential noise pollution imposed on local residents was considered right from the start of the structural design. The acoustic impact of this new barrier was very closely studied and the acoustic engineering consultant highlights the paradoxes, which had to be not only controlled, but mastered in this case during stadium construction. “We had to ensure top sound quality within the stadium shell, while preventing a “cathedral” effect, to ensure proper announcement audibility: to avoid frustrating the supporters, who’s only wish is to make the stadium thunder to the sound of their chants and to make it vibrate, while ensuring the tranquillity of local residents, who are in any case protected by noise regulations”.
Laurent Egamès concludes that maximum confinement of the acoustic intensity, while curtailing reverberation, was a balancing act perfectly performed by the acoustics engineer through creation, in his own words, of “a cauldron effect”, allowing the sound waves to be concentrated within the stadium.
He goes on to explain implementation of the “acoustic cap” installed above the stands to limit sound radiation towards the residential hillside by analogy and with reference to an aeroplane wing whose uplift if directed from the “underside intrados” to the “top side extrados”.
• Exclusive Précontraint Serge Ferrari® technology ensures dimensional stability and unmatched flatness.
• Unreinforced, the membrane resists tearing and its base fabric – comprising high tenacity polyester yarn – guarantees its strength.
• Its S2 surface treatment optimises performance of polyvinylidene fluoride (PVDF) alloys and limits adherence of pollutants and dirt.