Ytong reinforced masonry: an economical firebreak solution

Reinforced masonry, Ytong innovation for economical and quick to assemble fire walls

Classified A1, it is incombustible and provides excellent fire resistance. Thanks to its mineral properties, it is impervious to flames and smoke and greatly limits the rise in temperatures in the adjoining cells.

Healthy and durable, Ytong walls and partitions offer high performance fire protection. Among the fire protection solutions offered, reinforced masonry in cellular concrete stands out for its speed of installation and its lightness. In tertiary and industrial building projects, they make it possible to optimize implementation, by erecting large-scale firewalls in record time, and thus achieve significant savings in time and money.

For the projects of the future Maine Street shopping center located to the south of the agglomeration of Le Mans in Ruaudin (72), which will offer a retail area of ​​approximately 27 m000 with around forty shops, and the Ethiquable chocolate factory in Fleurance in the Gers (2), which will bring together production, warehouse, offices and a shop open to the public, two different solutions of Ytong fire-resistant masonry have been selected.

Taking into account the constraints of each of these projects, the technical department of Xella recommended optimized construction techniques. Thus, the Ytong Gigabloc was implemented mechanically for Maine Street, while Ytong Compact 20 blocks associated with Ytofor were laid manually for the Ethiquable factory.

Reinforced masonry and large format Ytong blocks: high performance fire protection

Thanks to the mineral nature of cellular concrete, its intrinsic properties and its high thermal resistance, Ytong reinforced masonry solutions are particularly suitable for fire-rated applications. Incombustible, their melting point is around 1200 ° C, and they do not emit any toxic or flammable gas.

Aurélien REGNIER from the BCG company, which carried out the structural work and civil engineering for the Maine Street project, describes the challenges of the project: “The idea was to build a hypermarket linked to retail stores for a surface area of ​​27 m000. The issue of firewalls was central because they had to separate the many adjoining commercial cells which have “at risk” stores (generally catering areas include kitchens). Ytong fire protection solutions adapted perfectly to its constraints. "

The cellular concrete being endowed with fire-resistant properties largely met the requirements of the program.

“The material has several interests. Technically, its lightness compared to fire-retardant chipboard or concrete facilitates its handling and installation. Ytong Gigablocs require the use of machinery, but their handling and installation are much easier than with concrete, which is much heavier. Cellular concrete is also more efficient in terms of sound and thermal insulation.

In all, we had to erect 20 aerated concrete fire walls 32 to 40 m long and 7 to 8 m high. Reinforced masonry allows these very long and very high walls to be made without the need for intermediate posts and each one could be erected in a week.

The technical service of Xella was a great support for the sizing. Thanks to the technical study carried out by their service, we were able to determine the products and details of the masonry as well as the principles of fixing the blocks. In addition to the twists of 10 placed at each row lengthwise, the walls are attached to the metal framework of the building by “fusible” fasteners. The technical service has determined the type of fastening required depending on the areas and the metal frames to hang each wall. "

Xella technical service engineer, Vincent SENECLAUZE adds: “The specifications for the Maine Street project required 3 hours of firebreak. As our cellular concrete is very efficient, we reach 3 hours with blocks 10 cm thick, but when it comes to walls with large dimensions, other parameters come into account. We have issued a technical note for a given product with its charac- teristics, dimensions, fire rating, fire response as well as a wind load hypothesis and the reference of the sizing standard used, which is Eurocode 6.

These calculations made it possible to validate the Ytong Gigabloc 15 solution. The choice of this constructive solution is exceptional for walls of this dimension (15 cm thick). They measure 120 x 62,5 cm and are grooved on their upper part. In this groove, a standard reinforcement, a tor of 10 in each row, reinforces the resistance of the wall. "

As for the project for the new Ethiquable factory, the L2C company, commissioned by the promoter Essor Agro for the structural work and firewall work, chose the Ytong Compact 20 solution with the Ytofor reinforcement.

Its director Vincent Soury testifies to the strengths of the solution: “Aerated concrete achieves good performance in terms of fire protection and thermal resistance. It is the ideal compromise for this type of program, a factory also welcoming the public. 2H fire rated performance was required. "

Faster implementation

For the Ethiquable building, the choice fell on manual installation with Ytong Compact 20 blocks and the Ytofor reinforcement.

Vincent Soury from L2C says: “The process remains traditional. Thin joint mounting is convenient because the weight of the wall remains light. The strengths of this solution are undeniably lightness and ease of implementation. The Ytofor is a reinforcement, packaged in the form of a roll, which is placed every row to remove stiffeners and reinforced concrete links. The advantage of Ytofor is that you don't have to create any chaining at all, which makes execution super fast. We save at least 50% of the time spent with these dry masonry solutions, because nothing stops the workforce with Ytofor. You can go up to 55m² during the day. "

Vincent SENECLAUZE (Xella) highlights the technical performance of the solution: “The installation of Ytofor every row, there it is every 25 cm, allows to obtain a better mechanical reinforcement of the structure of the wall, with a reinforcement distributed over the entire height. Thanks to Ytofor, we improve the expansion capacities.

The innovative nature of Ytofor can sometimes raise questions, but we reassure our interlocutors because we have all the certifications on its sizing and its implementation. In addition, the support of our technical team allows a personalized and optimized response for each project.

Our technicians-demonstrators are involved in all phases of the site: installation, demonstration ... "

For Aurélien REGNIER (BCG) who implemented Ytong Gigabloc on Maine Street “The installation was carried out by 4 people: an operator controlled a crane, a person on the ground helped to handle the blocks, and in a nacelle 2 people were respectively responsible for positioning the blocks and making the joints. On the top of the Ytong Gigabloc, a groove accommodates a tor of 10 which is fixed with YtongFix adhesive mortar, thus allowing a cleaner construction. "

The environmental performance of aerated concrete

Ytong reinforced masonry solutions meet energy performance objectives, which are also decisive criteria for the building of the Ethiquable chocolate factory. The brand has chosen to meet the specifications of the In'NoWatt call for projects of the Occitanie Region, a certification that goes beyond the HQE benchmark and rewards innovative construction operations that limit their energy consumption with a lowest possible carbon footprint throughout their life cycle.

Aurélien REGNIER (BCG) also attests to the durability of the Ytong masonry used in the framework of the Maine Street project: “Aerated concrete is virtually indestructible. The life of the material is excellent. "

Reinforced masonry fire protection solutions Zero chaining

YTONG GIGABLOC - a quick assembly solution (crane or lift required)

Lightweight, insulating and large in size, Ytong Gigabloc (120 x 62,5) allows large-scale fire walls to be erected very quickly, using a small construction crane. This installation facilitates handling, considerably reduces installation time and is more economical.

In addition, existing in two dimensions, the blocks are easily cut, which ensures rapid installation and perfect adaptability on the site.

Finally, they ensure the safety of people and equipment thanks to their high fire-rated performance (EI 240) and their excellent thermal properties which make it easier to resist disasters.

Ytong Compact 20 associated with Ytofor

The association of Ytong Compact walls with the Ytofor reinforcement in the horizontal joints reinforces the resistance to transverse forces and provides great freedom for the design and construction of fire walls. It eliminates horizontal and vertical chaining and simplifies the implementation of the site (up to 25% faster to install).

The Ytofor metal frame is integrated directly into the joints of the masonry, replacing the usual vertical and horizontal chains. Economical and quick to install, it requires no poured concrete, no chains, no specific accessories.