Fabric formwork is a building technology that employs geotextile fabrics as the formwork material for concrete construction.
In general, fabric formwork uses structural membranes as the primary facing material for the concrete molds. Unlike other formwork systems, fabric formwork is very flexible and can provide different shapes to concrete structures.Â
Its first application can be attributed to Gustav Lilienthal, a builder and inventor, who combined his knowledge in textiles with construction to invent a fabric-formed suspended floor.
Image Courtesy: C.A.S.T
1. Features of Fabric Formwork System
- Fabric formwork systems can be used for cast-in-place and precast concrete construction applications.
- Fabric formwork is flexible enough for the shaping of beams, columns, walls, etc.
- The fabric mold takes the intended shape under the pressure of wet concrete.
- Geotextile fabrics as a formwork material work in tension, reducing the amount of form material required to support the hydraulic pressure of the wet concrete.
- Fabric forms provide better durability, surface finish, and architectural aesthetics compared to traditional formwork.
- Fabric forms help to achieve complex shapes by using less concrete and reinforcement.
- Geotextile fabrics are permeable enough to allow excess water and air bubbles in the concrete mix to dissipate through the formwork, providing a stronger and impermeable concrete.
- Fabric forms have widespread applications in the area of architecture where it is being used to explore new, complex, and intricate shapes.
2. Geotextile for Fabric FormworkÂ
Geotextile fabrics used for formworks are flexible fabrics that possess high strength and do not tear under the action of loads. These materials are also referred to as polymer fabrics.
Geotextile fabrics are made using polyolefin compounds taken from non-aromatic carbon and oxygen molecules. For formworks, woven types of geotextile fabrics are commonly used. They can be:
2.1 Woven polyethylene fabrics
Woven polyethylene fabric has the following properties:
- High flexibility
- High resistance to strong acids, bases, gentle oxidants, and reducing agents
- Relatively low melting point depending on its density
2.2 Woven polypropylene fabrics
Woven polypropylene fabrics are commonly used for fabric-formed concrete. These fabrics as formwork possess the following properties:
- High melting point
- Light in weight
- Low resistance to chemical deterioration
- High flexibility
- Relatively strong
3. Advantages of Fabric FormworkÂ
- Consume less concrete and reinforcement
- Provide better surface finish to concrete structures
- Increased impermeability and durability of the structure
- Fabric costs less compared to conventional formwork material
- Reduced carbon dioxide emission due to less concrete consumption
FAQs
Fabric formwork is a building technology that employs geotextile fabrics as the formwork material for concrete construction. Its first application can be attributed to Gustav Lilienthal, a builder, and inventor, who combined his knowledge in textiles with construction to invent a fabric-formed suspended floor.
The material used for fabric formwork is geotextile. Geotextile fabrics used for formworks are flexible fabrics that possess high strength and do not tear under the action of loads. These materials are also referred to as polymer fabrics.
Read More