Fabric formed concrete is the result of pumping a highly fluid concrete mix into specially woven fabric “envelopes.”
This method of erosion control allows for fast, economical construction of revetments, landfill containment systems, holding ponds, bridge scour repair, bridge or dock piling reinforcement and countless other applications.
This innovative technique utilizes fabric woven of high tenacity nylon yarn into a variety of forms including mats, pile jackets and bags.
At the work site, the custom-made forms are positioned and sewn together with hand-held sewing machines.
They are then pumped with fine aggregate concrete and allowed to cure.
Fabric formed concrete eliminates the need for time-consuming wooden forms and expensive lifting equipment and/or cranes.
Fabric forms have the unique advantage of allowing the concrete pumped and cured below the water line — making site preparation much easier.
Labour and material costs reduced due to simpler installation and more efficient use of concrete.
This efficiency makes fabric formed concrete budget-friendly by design.
In addition to economical advantages, fabric form concrete is the smart choice for soil erosion control because of its high versatility, durability and effectiveness.
Worldwide, there are millions of square feet of fabric formed concrete in place.
Types of fabric formed concrete:
Efficient reinforced concrete beams, shaped to follow their bending moment curves, can be constructed using fabric sheets.
The ability to easily form curved, variable-section beams has prompted University-based engineering research in North America, Europe, and the UK, into the performance characteristics of these efficiently curved beams.
The use of fabric tubes to form columns is a natural application of fabric forming. Symmetric fluid pressures force the fabric to form a perfect circle.
As the fabric tube forms fold flat, significant savings in shipping and storage are achieved over rigid formwork.
Unattractive spiral lines of cardboard tube forms are avoided.
Fabric formed footings offer significant benefits over lumber:
- Prevention of movement of ground moisture through the footing and inside the building
- Prevention of ground water contamination by cement fines
- Prevention of forming lumber waste
Unique precast concrete panel designs can be constructed using flat fabric sheets as molds.
The natural deflections of a fabric sheet supported from below, produces beautiful and structurally efficient shapes.
Thin shell structures
Molds for lightweight compression shell structures and building components such as thin-shell compression vaults and double curvature wall panels can be made by placing concrete on a hanging sheet of fabric.
Simply inverting the tension-resistant shapes given by the fabric membrane directly produces pure compression geometries.
A simple mold technology using flat sheets of fabric stretched over plywood supports makes possible the economic construction of reinforced concrete trusses.
Construction details and structural design methods are being developed in University-based research at the University of Manitoba (Canada).
Architect Kenzo Unno has developed several different methods for constructing beautiful fabric-formed walls.
These methods provide large reductions in the materials consumed in construction. Sheets of rigid insulation are used in place of plywood on the flat side of a fabric-cast wall, while a fabric formwork membrane provides a beautiful architectural finish on the other side of an insulated, cast-in-place, structural wall.
The use of structural fabric form-liners, installed in modified plywood wall formwork, can produce unique architectural and structural designs.
Source : builderbill and UK Architects Journal