Gran Bazar de Lyon

Example of French Renaissance

27, Rue de la République 69002 Lyon

27, Rue de la République 69002 Lyon. The project consists of a structure designed in an urban setting, class C3H according to UNI EN ISO 12944-2. An interesting insight into the architectural project can be read in the article “Le Grand Bazar de Lyon est mort, vive le Grand Bazar” published on the website pointsdactu.org. Below is a brief summary:

LERICI CASTLE
Nord Zinc was involved in the expansion project for the Geo- paleontological museum at the Lerici Castle. The expansion involved the construction of a steel-glass case to enclose one of the courtyards inside the castle. Inside the castle the structure develops over two floors with an internal connecting staircase. The roof is made of glass supported by a metal structure, which is why a company like North Zinc proved to be such an important partner. Lerici Castle stands in a panoramic location dominating the rocky peninsula of Lerici. The castle was built from 1152 AD onwards and underwent numerous transformations by the Maritime Republics of Genoa and Pisa, who contended for the property given its strategic location. Only in 1555 did the castle begin to take on its current appearance.
THE REQUEST OF THE CLIENT
The Architect Roberto Salvaterra, designer of all the phases (preliminary, final and execution), project manager, and coordinator for safety during design and execution, together with Engineer Francesco De Martino, who was in charge of structural design, decided to create a project with high sustainability contents, applying the concepts of participatory planning. Nord Zinc was commissioned to develop the corrosion protection and aesthetic system for the steel manufactured products. The first step, as always, involved the identification of the environmental corrosion class in which the manufactured product would be required to operate, according to the classification foreseen by UNI EN ISO 12944. The corrosion class was identified without doubt as C5M (off-shore environment). The client required a corrosion protection system with a durability of at least 20 years. The third request posed by the Client contemplated the perfect integration of the work with the architectonic context, therefore an aesthetic and decorative request; this made it vital to paint the structure with a coating that could guarantee good colour retention.
THE TECHNICAL PROPOSAL
The Nord Zinc technicians proposed the SISTEMA TRIPLEX C5M – L, which foresees a combined hot dip galvanising-powder coating cycle, with an intermediate nanoceramic treatment. The durability was calculated based on the performance data provided by the UNI EN ISO 12944. The structure is composed of metal structures with profiles featuring an average thickness of over 6mm. The corrosion protection is applied using the hot dip galvanising method according to UNI EN ISO 1461. In environmental corrosion class C5M, hot dip galvanising suffers a loss in thickness of about 6.3 microns per annum. Nord Zinc’s experience, together with the available bibliography, makes it possible to affirm that – operatively on manufactured product of this kind – if a steel-zinc alloy of about 100 micron is used, this will be capable of ensuring protection for over 15 years. To reach an exceptional 20 years, the hot dip galvanising is combined with a film of polyester powder paint. The coating system is applied after surface preparation using the nanoceramic layer: this operation is vital to achieve perfect adherence of the coating film to the hot dip galvanised support. According to UNI EN ISO 12944, the cycle is able to ensure low class (5 years) corrosion protection, which, added to that guaranteed by the hot dip galvanising satisfies the 20 year requirement of the Client. In actual fact, it is possible to reach even higher performance results: the combined system generates a durability that goes well beyond the mere sum of the individual cycles. In this class of environmental corrosion, the sum is increased by 20%, bringing the total durability to 24 years.
COATING TYPES
To ensure a good colour hold, we chose to use a Qualicoat Class 1 polyester powder coating:10 years of colour hold without fading.
THE CONSTRUCTION ASPECTS
It is definitely vital to choose the anticorrosive method appropriate for the class of environmental corrosion in which the manufactured part will be required to perform, but this can be affected by errors in design and subsequent surface preparation of the manufactured product. UNI EN ISO 12944 recommends that, during the design and manufacturing of metal products, some particular aspects must be taken into account. First of all, it is recommended to avoid “corrosion traps”, such as boxes that retain liquids, sizes and overlapping of elements that do not allow a perfect realisation of the protective system. The choice of the type of profiles that comprise the manufactured product and the surface preparation of the latter must be made in accordance with ISO 8504-1. Operating in environmental corrosion class C5M, the surface of the manufactured products must be prepared according to grade P3 foreseen by ISO 8504-1, which requires us to: avoid sharp edges, countersink the holes, avoid the presence of weld spatter, smooth and clean welding seams, rounded lamination edges with a radius greater than 2mm, the thermal break face removed and rounded edges, etc. The designers therefore chose to use the following profiles: tube for risers, hot rolled beams for the deck, hot rolled plate for stairs and parapets, reducing to the extent possible the use of live edges. The on-site mechanical assembly also guaranteed the perfect realisation of the anti-corrosion and finishing system on the industrial plant.
INSTALLATION
Installation took place in early August 2011. The pieces were lowered inside the castle with the aid of a helicopter, so as to prevent interference with city traffic. The assembly phase went very smoothly with minor inconvenience to the users of the Castle, respecting a work plan that guarantees utmost discretion. Thanks to the “clean site” ensured by the dry constructions made of steel, in just three months the new facilities were delivered to the Museum, ready to host a new exhibition.