Durability in Design
- Marine structures
- Bridges and tunnels
- Water treatment plants
- Pre-cast concrete units
Based on more than 25 years of experience, Formtex® Controlled Permeability Formwork (CPF) Liners are recognised for providing a cost-effective method of improving the durability and surface finish of cast concrete.
Using CFP liners can potentially double the lifetime of concrete structures.*When compared with equivalent concrete cast without the product, concrete cast against CPF has enhanced resistance to carbon dioxide, ingress of chloride ions and frost attack, reduced permeability, enhanced surface tensile strength and improved surface hardness.Formtex® – how it works Formtex® is a two-layer CPF liner consisting of a drainage layer allowing water and air to escape and a filter layer with pore size designed to retain cement particles.The main function of the Formtex® CPF liner is to drain surplus water and air from the surface of freshly poured concrete during compaction. When water is drained, the water/cement (w/c) ratio in the concrete cover is reduced, providing for denser and stronger concrete, which improves the durability of the concrete considerably.
Formtex® is available in two versions Formtex® PSA is self-adhesive, providing for fast and easy mounting. The self-adhesive backside is covered with a siliconised plastic foil, making it possible to place the Formtex® liner on the form and remove the foil without tensioning or misplacing the CPF liner, thus preventing folds or poor joints.
Water tank*, Grossglattback, Germany
Formtex® CPF liner provided for a denser and smooth concrete surface without the use of release agents. Reduced risk of microbial growth could be documented and cleaning of the tank was simplified.*
* DVGW Certified for use in drinking water application.
Crash barrier, Zürich, Switzerland
The complex structure with inclining surfaces typically results in many blowholes and surface blemishes requiring extensive repairs after the formwork is removed. Formtex® CPF liner provides for an almost blowhole-free surface with increased resistance to chloride ingress and frost/thaw degradation.
Container Terminal No. 9, Hong Kong
The very large and heavily reinforced structure exposed to high chloride, high carbon dioxide and high moisture levels as well as a hot environment required a dense, yet workable concrete. Formtex® CPF liner provided for a faster and safer workflow. Further, the increased lifetime and lower maintenance costs of the container terminal were decisive factors.
The lifetime and maintenance costs of this prestigious project were decisivefor the choice of Formtex® CPF liner. Formtex® CPF liner provided for documented effects to improve the overall quality of the concrete cover layer. Fewer blowholes and improved resistance to ingress of gasses and liquids made Formtex® CPF liner a cost-effective choice.
The requirement for a smooth concrete surface resistant to aggressive substances and cleaning procedures using high pressure water cleaning was met by using Formtex® CPF liner. Typically, the ingress of chlorides, moisture and frost/thaw degradation is reduced by more than 50% with Formtex® CPF liners.
Formtex® CPF liner provided for a smooth and resistant concrete cover layer, increasing the lifetime and reducing the maintenance costs of this beautiful bridge. The ability to provide extensive documentation of the CPF effects was in focus.