Metal construction, a dynamic supported by engineering structures, industrial and commercial buildings

Economic situation and activity of metal manufacturers

A positive trend, according to the president of the SCMF, Roger Briand, which ensures French metal manufacturers can meet their investments, both in terms of personnel and the modernization of their industrial tools. Remember that the 800 French metal construction companies, mainly SMEs and mid-sized companies with a family structure, allocate 10% of their activity annually to the modernization of their production units.

The 2023 turnover therefore stands at around 4,3 billion euros, 10% of which comes from exports, which represents a production of around 780.000 tonnes of steel. A sector of activity which is essentially based on private investment, with public sources becoming rarer. Furthermore, Roger Briand specifies that metal constructors have had to face difficulties in managing their activity planning. As contractors are increasingly hesitant, the postponement of decision-making has in fact directly affected the programming of the activity.

For Roger Briand:“However, over the past 3 months, we have noticed a resumption of files and project launches; order books now represent between 6 months and 12 months of activity. A comfortable volume to calmly approach 2024.”

Metal construction activity by type of work

The developing metal construction markets are numerous. In the foreground, the construction of engineering structures such as viaducts, bridges, footbridges, stations, including the structures of metro lines 16 and 17 of Greater Paris, have made it possible to develop the activity. Another important part of the activity concerns industrial and commercial buildings, with the reindustrialization of France as a backdrop, although it is true that this is not the only reason. Let us then mention the construction of shade structures and photovoltaic power plant supports, representing a market that has become very dynamic, without counting on the rehabilitation of existing metal structures, which is also growing. In this respect, let us point out that metal construction is particularly well suited to the renovation and rehabilitation markets.

Evolution of concluded deals

Productivity

The activity rate of our profession is closely linked to the index published by the Bank of France of the capacity utilization rate of all production in France. Roger Briand notes that, since May 2023, the rate has fallen slightly to reach in December 2023: 76%. If the decrease in this rate is confirmed, the evolution of the general activity of the profession could be impacted, knowing that the leading market for metal constructors concerns industrial buildings (1% market share).

Evolution of the workforce

The recruitment needs of metal manufacturers amount to more than 20 jobs over the next 000 years. The lack of training for these professions forces entrepreneurs to develop internal training but also to increase the number of work-study contracts.

Evolution of order books

The main challenges of metal construction

Roger Briand also takes the opportunity to take stock of the major challenges facing metal construction. “Like all sectors linked to construction and energy, it is the environment, decarbonization, the circular economy that leads us to innovate and design our constructions through the prism of carbon footprints and resource economy. As a result, we orient our practices towards reuse which presents the most virtuous way for construction. » On this subject, Roger Briand recalls that French metal manufacturers have the most impeccable material in terms of recycling and therefore the circular economy. With 97% of long steels recycled and recyclable, this effectively contributes to the preservation of natural resources. And Roger Briand elaborates: “It must be said that we benefit from an exceptional material which is infinitely recyclable while retaining its mechanical characteristics, without any alteration over time. Our constructions have the advantage of being easily dismantled and reassembled, this property constitutes an asset to promote reuse. Especially since it is a practice tending to develop. This is why we have just submitted the first professional recommendation concerning the reuse of structural steel materials, a document drawn up by the Industrial Technical Center for Metal Construction (CTICM), which is the profession's research office. »

Before concluding: “We did not wait for RE2020, the AGEC law or the REP to engage in a responsible economic approach. At the same time, today, the development of low-carbon steels and tomorrow that of zero CO2 emissions thanks to green energy places steel at the forefront. The carbon footprint of our buildings is therefore intended to be very competitive, and they already meet future environmental challenges. »

THE SCMF pleads against the draft decree modifying the specifications of eco-organizations

Building on the observation that the General Directorate for Risk Prevention began this month a consultation aimed at reviewing, for the wood sector, the financing arrangements for the REP PMCB (construction products and materials in the building sector), Roger Briand deplores the fact that the administration wishes to pass on part of the costs corresponding to the treatment of this wood at the end of its life to all those involved in other construction products and materials (apart from concrete).

For Roger Briand: “The players in the metal sector refuse such an option. For more than a century, metal construction products and materials have been widely recycled, today reaching a level of excellence with more than 90% recycling rate (rate recognized in the specifications of eco-organizations) . Considering the investment made by our sector, it goes without saying that we consider it a double punishment to have to finance the greening of activities in other sectors, when the metal is already 100% circular. Today, we are developing the reuse of our products and we are also making all our efforts and investments to decarbonize our recycled steel production as quickly as possible, in particular by using electric furnaces powered by green energy. The economic effects of adopting such a measure would result in a distortion of competition, more than significant impacts on our entire ecosystem and would jeopardize our current investments and our sector. We therefore consider it legitimate to be exempt from this system, given the exemplary nature of our activities with regard to the objectives pursued by the REP. We have also contacted the Ministry of Ecological Transition and Territorial Cohesion on this subject for an upcoming meeting. »

Examples of some references of renovations carried out in metal construction

Autreville motorway viaduct (54) by Berthold

Dating from 1971, this full-width highway deck bridge makes it difficult to replace new. In addition, the significant increase in traffic and period design flaws have excessively “tired” the bridge, which is now under threat. After diagnosis and analysis by CEREMA, the DIR Est awarded the long-term repair contract for the structure worth €32 million to the Demathieu / Baudin Chateauneuf / Berthold group. This is an exceptional renovation due to its scale and its principle which combines the reuse of the existing metal structure with the addition of new relay structures. More precisely, it involves reinforcing the existing structure from below, with a new metal box structure, and from above with a fully connected Ultra High Performance Fiber Concrete slab.

And the banks have not been published with the new replacement of the retaining devices (new parts of structure receiving new safety equipment to today's standards). In addition to the complete repainting of the metal frame, the work consisted of the creation of new concrete and metal headers between the piers as well as a new supporting structure (4 box girders) installed by river under the existing structure (around 3.500 tonnes of steel). Note also the addition of reinforcements to the existing structure (around 50 tonnes of steel) and the transfer of loads from the old to the new (around 200 supports simultaneously), such as the replacement of the edge boxes of the structure to bring the retaining devices up to standard (around 400 tonnes of steel).

Other highlights of this reference, the welding of connector studs on the metal slab (around 100.000 studs) such as the casting of a UHPC distribution slab (to stop the progression of fatigue in the decking).

Renovation of the Béziers Exhibition Center (34) by Cabrol

In order to adapt to the needs of local economic players, the CCI of Hérault has invested in the renovation and extension of the Béziers Exhibition Center (7.200 m2). A project which was broken down into several phases between: studies, manufacturing in the workshop, removal of the existing, assembly of the framework, implementation of the roofing and cladding. The removal of the existing building (1.640 m2 of cladding, 4.000 m2 of roofing, bracing, purlins and awnings) preceded the work of replacing the IPE purlins with galvanized Z purlins, but also the reinforcement of the existing framework (36 tonnes) and repainting.

Note also the creation of the metal framework of hall 4 (25 tonnes), hall 3 (19 tonnes), a workshop (7 tonnes) as well as a guards' accommodation (6 tonnes), as well as the implementation new roofing (4.000 m2) and cladding (2.100 m2) mainly in sandwich panels. Client: CCI de l’Hérault – Architect: ID&M – ARCAN

Business resort Paris Pleyel by SMB Constructions Métalliques

SMB, a subsidiary of SOPREMA Entreprises, is working on the construction site of the Paris Pleyel Business resort for the construction of the steel structures of the work. A large-scale program which left no room for improvisation, from in-depth studies to site logistics, including implementation at a height exceeding 100 m.

The hotel component (4*) of this ambitious complex, designed by architect Sretchko Markovic (163 Ateliers), will be delivered in spring 2024, at the dawn of the Paris Olympic Games. It includes the major restructuring and reconversion of the emblematic Pleyel business tower, which will accommodate nearly 700 rooms, restaurant areas, a bar and a panoramic swimming pool on the 40th floor at more than 130 m high. Two new tertiary buildings, each measuring more than 18 m000, are currently being constructed at the same time. The first of 2 floors, called “Music-Hall”, is located at the foot of the historic tower. The second, “Maestro”, is a new 6-story tower. The conference center, the common base of these two new buildings, will offer a multifunction and modular reception space of 25 m8, capable of accommodating up to 000 people.

On the Pleyel Tower, 3 additional levels, including the one dedicated to the swimming pool, were added to reach 41 floors in total.

Between 6 to 9 companions assembled the 250-ton metal cap between July and December 2022. The access conditions and the dizzying height of this heavy renovation were integrated from the study phase by reducing the weight and length of the structural elements. . This new stylized structure allows the installation of glass walls of the rooftop offering a breathtaking view of Paris. The supporting framework of the 25-story Maestro tower has been coming out of the ground since November 2022 and should be completed in 2024. It is the only 100% metal* high-rise building currently under construction in France. This exoskeleton with its original architecture reaches a total weight of nearly 5.000 tonnes. The metal boxes forming the diagonals, 18 to 20 m long**, are linked together by nodes in the shape of an X or K. Each of these nodes represents a technical feat requiring up to 1.500 hours of manufacturing and nearly 600 kg of filler metal per part for the most complex. The complex geometry of the structure imposed manufacturing and implementation tolerances close to the millimeter. Finally, note that the frame has a white finish echoing the new aluminum envelope of the tower.

* Only a concrete core for the elevators.

** Section of 800 x 800 mm, reconstituted and welded in S355 or S460 sheets up to 150 mm thick.

• Developer/Investor – Project management: Pleyel Investissement (subsidiary of the life insurance company, based in Strasbourg: AFI.ESCA – Burrus Group) – owner of the whole
• AMO: Financière des Quatre Rives, represented by Boris LITTY, Managing Director – Founder – Liberg Group
• MOE: Pangea Design and Engineering
• Architect: Sretchko Markovic (163 Workshops)
• Operator of the hotel and the conference center: H-Hotels (1st establishment of the German brand in France)
• Interior designer of the hotel: Agence Axel Schoenert architectes
• Steel structures: SMB Constructions Métalliques

Rehabilitation of the Bel'Air office building in Nanterre (92) by Vilquin (Fayat Group)

Located in the heart of the city of Nanterre, the former headquarters of the INPI had been vacant since 2016. It was completely decontaminated and asbestos removed before being recycled. The new office covers more than 5.400 m2 spread over 7 floors (including a cafeteria on the ground floor – ERP-, a collaborative space, a bicycle room, a roof terrace, and a 500 m2 green terrace) for a cost of work of 14,3 million euros and some 125 tonnes of steel. The majority of the concrete structure was retained for the new construction, which notably made it possible to reduce CO2 emissions by 60% compared to a new construction from scratch (370 tonnes).

On the environmental side, the BEL'AIR building is energy efficient and aims to obtain several certifications and labels (BBC Effinergie Rénovation, HQE® Rénovation Excellent, BREEAM Very Good and WiredScore Gold). It should be noted that Vilquin created new floors, preserved the existing facades (except for the addition of metal profiles to maintain the cantilevered floors), as well as the addition of an elevation (creation of an additional floor) .

• Client: NOVAXIA
• AMO: AMO Environment IDEAM/ELAN
• Architect: CALQ Architectes