CPF liner Zemdrain^® and its impact

Zemdrain^® is a Controlled Permeability Formwork (CPF) liner made of polypropylene, supplied in rolls. It is installed onto the formwork and the concrete is then poured. During the concreting process and afterwards, the excess water required for processing the concrete is drained
downwards and the air is drained upwards. During compaction of the concrete and subsequent curing, the w/c ratio on the concrete surface is reduced and an improved concrete
matrix is created by optimizing the structure. In addition, the water stored within the Zemdrain^® structure is returned to the concrete during the setting phase (curing of fresh concrete). Afterwards Zemdrain^® is then completely removed from the formwork.

• CPF liner Zemdrain^® Classic: For single use
• CPF liner Zemdrain^® Classic TW: Tested and approved according to the highest drinking water criteria
  
• CPF liner Zemdrain^® MD: For multiple use
  
• Zemdrain^® Classic prefabricated: For round container formwork
  

The Controlled Permeability Formwork (CPF) liner Zemdrain^® has been used on various projects worldwide for many years. It is particularly useful for concrete structures that are exposed to aggressive chemical or mechanical environments. The use of Zemdrain^® formwork liner ensures that concrete structures remain intact and have a proven longer service life.

Zemdrain is used in the following areas:

1. Wastewater disposal facilities and sewage treatment plants
   
2. Structures in the drinking water sector
3. Transport infrastructure
4. Structures near the sea and under water

The effect is as simple as the application is ingenious: The drainage effect of Zemdrain^® initially allows air to escape during the compaction of the concrete and the excess water is drained away. During the curing process, on the other hand, a continuous supply of moisture is ensured in the area close to the surface. This results in a dense, hard concrete surface with minimised blowholes. During the life cycle of the structure, this hardened concrete surface finish protects the reinforced concrete from mechanical and chemical attacks. In particular, the penetration of water in freeze-thaw environments, attack by chlorides under saline conditions and carbonation due to CO₂ is reduced enormously. This increases the service life of the concrete surface and reduces the need for costly renovations.

• Increased service life of the concrete surface
• Value retention of the concrete surface
• Proven cost savings over the total service life of the structure
• Increased abrasion resistance
• Dense, hard and blowhole free concrete surface
• Reduction of blowholes - saves reworking, especially in exposed concrete areas
• Simple formwork application
• Multiple use is possible with Zemdrain^® MD
• Release agent is not necessary