In Châtelet-Les Halles, Kemper System takes the underground waterproofing train

Kemper System, a specialist in building envelope protection, has developed a unique, perfectly waterproof intrados lining system, Kemperol® CEV, which was selected by RATP for the waterproofing repair of the tunnels at the Châtelet-Les Halles interchange hub.

Patented alliance * of high performance polymer compounds, Kemperol® CEV demonstrates an exceptional level of resistance to back pressure and cracking, perfectly adapted to the constraints of buried premises subjected to high stresses. Guarantor of the sanitary quality of closed spaces, it ensures user comfort.

An extraordinary site

More than 30 years after its construction, the Halles site is currently the largest construction site in the capital.

A strategic hub for transport, Châtelet-Les Halles is the busiest underground train station in the world. Every day, some 800 passengers pass through this station on one of its three RER lines and five metro lines. 

Combined with the growing level of attendance, the observed aging of the infrastructure and the evolution of safety standards led to a major restructuring of the site in 2010. The renovation project notably resulted in the recomposition and modernization of all the underground spaces - interchange hall, platforms and connecting corridors -, for a reorganized and streamlined route. Implemented over six years, the redevelopment of the Châtelet-Les Halles station aims to improve the comfort and safety of passengers.

A unique sealing solution from Kemper System

Located 25 meters below the level of the Seine, the galleries and tunnels required a "latest generation" waterproofing system for their renovation, adapted to the heavy constraints of underground premises.

Specializing in the repair and structural reinforcement of underground structures, SPIRALE, a subsidiary of the JEI Group, is particularly experienced in complex waterproofing and sealing work.

Recognized for its expertise in this type of work, the company won the call for tenders launched by the RATP for the waterproofing of the inside of tunnels in the Châtelet-Les Halles interchange hub.

A long-standing partner of Kemper System France, the applicator chose to implement the Kemperol® CEV waterproof casing system, the development of which it initiated by expressing its need for a response adapted to the specificities of its construction sites.

As this is a new solution on the market, the project owner wanted to ensure the effectiveness of Kemperol® CEV through a test, entrusting SPIRALE with only the first phase of the 500 m2 project in June 2015. Fully convinced by the results obtained, the RATP awarded the entire contract to the Kemper System France partner applicator, i.e. an additional 4 m500.

Three other Parisian metro stations, including Concorde station, are currently undergoing a repair of the watertightness of their tunnels with the Kemperol® CEV system.

New player in the underground waterproofing solutions market, Kemper System France has filed a patent application to protect the innovations that make up Kemperol® CEV. An ATEx is in the process of being obtained.

Site information

Geographic location: Châtelet-Les Halles, Paris

Project owner: RATP

Applicator: SPIRALE, JEI Group (91)

Type of support: concrete formwork

Surface area: Phase 1 - 500 m² / Phase 2 - 1 m² / Phase 000 - 3 m²

Timeline: Phase 1: June - December 2015 / Phase 2: April - June 2016 / Phase 3: September - December 2016

A lasting solution with extreme resistance

Adapted to noble buried premises, tunnels and underground passages, the Kemperol® CEV is a perfectly sealed casing system, resistant to back pressure and cracking.

Innovative intrados waterproofing process stemming from 50 years of Kemper System sealing expertise, the Kemperol® CEV coating incorporates the latest generation of polymers. It constitutes an interior screen adhering to its support, completely sealed against liquid water and water vapor.

A true sealing process, Kemperol® CEV forms a homogeneous membrane which resists application below the level of the water table. Composite system with variable elasticity, it is insensitive to the movements of the support and demonstrates extreme resistance to cracking up to 4 mm, without delamination.

Traditionally executed with waterproofing based on mortars or hydraulic plasters, the inner casing gains in performance thanks to the Kemperol® CEV. This system considerably improves the ambient atmosphere in buried premises by eliminating any phenomenon of seepage or vapor migration.

A healthy and versatile interior coating solution

Made from modified epoxy resins, the Kemperol® CEV system is cold-applied and solvent-free, and is flame- and odor-free. Recently patented, it has CE marking and A+ classification, guaranteeing low VOC emissions and indoor air quality.

Applied intrados with a thickness of only 2 to 4 mm, the Kemperol® CEV respects the shape and the initial interior dimensions of the works, and easily adapts to the constraints of the renovation.

In a reduced height-under-ceiling configuration, the system can be combined with a very thin reinforced epoxy floor covering, directly circulating, and endowed with high resistance to heavy traffic.

Depending on its field of use, Kemperol® CEV adapts to all traditional wall or floor coverings. It is notably offered with fireproof finish for public premises. Classified B-s1-d0, the system generates extremely low smoke toxicity in the event of a fire and ensures maximum safety for the public.

*Patent filed (15/01544) with disclosure authorization.

Kemperol® CEV performance

Vapor barrier: Sd > 200 m

Back pressure resistance: > 1,7 Mpa (17 bar)

Cracking resistance: 4 mm (without detachment from the support)

Resistance to mechanical stress (rolling, shocks, abrasion and punching)

Reaction to fire: B-s1-d0

Smoke toxicity: CITG < 0,006