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Concrete refurbishment using polyurea and crack injection

Concrete refurbishment and concrete repair

Concrete is one of the most widely used construction materials, amongst other things since it is cheap and is easy to manufacture. Unfortunately, concrete is subject to relatively fast progressive ageing if it is exposed to environmental effects and the correct measures are not taken to protect it. After only a few years or decades, the first signs of damage start to show. Crumbling parts and cracks don't just look unsightly, they can also become safety hazards. Concrete structures like parking garages, the tanks of sewage treatment plants or biogas plants are at particular risk and must be refurbished frequently.

Refurbishment of concrete and reinforced concrete by coating with polyurea

Coating with polyurea is an excellent way to protect concrete or reinforced concrete from the effects of the environment. Polyurea reacts in a few seconds and the affected surfaces can be used only a few minutes after the application is completed. Apart from this, polyurea is solvent-free and proof against many aggressive materials, abrasion-resistant and not sensitive to damp.


Due to its high elasticity (crack covering), in particular, polyurea is highly suitable for refurbishing and coating concrete structures. Correct concrete refurbishment by coating with polyurea is, of course, conditional on the surface being pre-treated and an appropriate primer being applied. Regardless of whether you are refurbishing cisterns, swimming pools, sewage treatment tanks or flat roofs, using polyurea you can achieve excellent concrete refurbishment results.

Dam refurbishment: Hard-core concrete refurbishment

The French Alps are part of the Western Alps and the highest peak, Mont Blanc, is a world famous paradise for winter sports lovers. Apart from this, the entire alpine region is a gigantic energy store with many dams that are used to supply drinking water and to generate water power to supply electricity. The concrete structures that are needed for this must be inspected on a regular basis and the concrete must be refurbished. When inspecting the Girotte dam near Hauteluce in Savoy in the French Alps, serious defects were discovered in concrete. This meant that the concrete had to be refurbished. The 510m-long dam wall that is 48.5 m high was completed in 1948. Refurbishing the concrete makes particular demands on the people involved and the material they use. In addition to a number of massive cracks, it was also established that the concrete was considerably prematurely aged. The uncontrolled loss of water was just another of the problems with this structure. After removing the loose concrete sections in the cracks and filling them with a special adhesive, acrylate gel was injected to close concealed and/or inaccessible cavities in the concrete. To protect the aged concrete at the weak points, the building contractor SPIE decided to use Polyura PC 4840 Purea material by Dratec. The French company chose to use the powerful WIWA DUOMIX PU 460 for the application technology. Michel Laksander, WIWA representative in France, dealt with the first use on-site to ensure reliable coating of this project and all future ones with SPIE.

Processing polyurea using the WIWA DUOMIX PU 460

The powerful WIWA DUOMIX PU 460 is the ideal system concept for applying polyurea and PU foam in the field of concrete refurbishment too. With powerful material flow heaters, phase monitoring, differential pressure shut-down and control of the mixing ratio the PU 460 offers high process reliability in all fields of application. There is an almost free choice of mixing ratio from 1:1 to 10:1, which means that nearly any form of mixing used for in-situ foam or polyurethane/polyurea elastomers can be applied – this is a particular advantage when refurbishing concrete structures.





WIWA DUOMIX PU HYDRAULIC – Protecting – Sealing – Insultating

The WIWA DUOMIX PU HYDRAULIC is the latest and brand-new addition to our DUOMIX PU Series. This hydraulic, compact, versatile and mobile unit is easy to use and can handle all types of polyurethane foam and fast curing polyureas.