Concrete Cloth - A new Future

Concrete cloth (CC) is a unique proprietary material. It has a very wide range of applications throughout the building & civil engineering industry. Concrete cloth is a flexible; cement impregnated fabric that hardens when hydrated to form a thin, durable, water & fire proof concrete layer. CC allows concrete construction without the need for plant or mixing equipment. Simply position the canvas & just add water. CC has a design life of above 10 years and is significantly quicker and less expensive to install compared to conventional concrete.

CC Material Properties 
Strength

Very high early strength is a fundamental characteristic of CC. Typical strengths and physical characteristics are as follows:

Compressive testing based on ASTM C473 – 07 
- 10 day compressive failure stress (MPa) 40
- 10 day compressive Young’s modulus (MPa) 1500

Bending tests based on BS EN 12467:2004
- 10 day bending failure stress (MPa) 3.4
- 10 day bending Young’s modulus (MPa) 180

Abrasion Resistance (ASTM C1353-8)
- CC lost 60% less weight than marble over 1000 cycles. 

Tensile Test
Abrasion Resistance (DIN 52108)
- Similar to twice that of OPC Max 0.10 gm/cm2

CBR Puncture Resistance EN ISO 12236: 2007 (CC8 & CC13 only)
- Min. Push-through force 2.69kN
- Max. Deflection at Peak 38mm

Resistance to Imposed Loads on Vehicle Traffic Areas

EN 1991-1-1:2002 (CC8 & CC13 only)
- Category G compliant
- Gross weight of 2 axle vehicle 30 to 160kN
- Uniformly distributed load not exceeding 5kN/sq m

Physical Properties
Initial Set≥ 120 min
Final Set.≤ 240 min.

Applications of CC
Ditch lining
CC can be rapidly unrolled to form ditch or tank lining. It is significantly quicker and less expensive to install than conventional concrete ditch lining and requires no specialist plant equipment. The 30m ditch shown below was lined in 45min.

Slope Protection
CC can be used as slope stabilization and other erosion control applications such as temporary and permanent slope protection, retaining walls, boulder fences, low level bunds and river bank and dam revetments.

Pipeline Protection
CC can be used as a coating for overland or underwater pipeline protection, providing a superior tough rock shield. In remote areas it can be used to coat steel pipe on site without expensive wet concrete application plants. CC will set underwater and provide negative buoyancy.

Ground Resurfacing
CC can be secured with ground anchors to rapidly create a concrete surface for flooring, pedestrian walk-ways or dust suppression. CC8 and CC13 have been tested to EN 1991-1-1:2002 (Resistance to Imposed Loads on Vehicle Traffic Areas)

Mining Applications
CC can be used as an alternative to poured or sprayed concrete or as a quick way of erecting strong permanent or temporary blast and vent structures and spall lining. CC has been successfully tried in Mpumalanga, South Africa.
Bund Lining
Earth containment bunds can be quickly lined with CC to provide an efficient, chemically resistant alternative to concrete walling.

Sandbag Reinforcement
CC has been proven to prevent the degradation of sandbags from sustained incoming fire, outgoing muzzle fly ash and environmental exposure. A sandbag wall protected by CC withstood 900 rounds of 7.62 NATO, fired by a GPMG LR at a range of 100m. There is currently over 5500sqm of CC being used by the British Army in Afghanistan.

Gabion Reinforcement / Capping
CC can be used to cap or repair gabion walls to provide long-term protection and prevent FOD (Foreign Object Damage). Covering gabions with CC also prevents water ingress which can cause slump, whilst protecting the geo-textile membrane from the effects of UV degradation.

Dust SuppressionCC5 was developed as a result of in-theatre feedback, for use as a dust suppression surface around Helicopter Landing Sites. Benefits include: speed of installation, durability, and good coverage (CC) will conform to the underlying ground conditions).

Advantages of CC

• Rapid-the material can be hydrated by either spraying it or fully immersing it in water. Once hydrated, it remains workable for 2 hours and hardens to 80% of its final strength within 24 hours. These times can be reduced by adding accelerants into the dry mixture at the point of manufacture;
  
• Easy to use-dry Concrete Cloth can be cut or tailored using simple hand tools such as utility knives. The PVC side can be supplied with an adhesive backing and the fibrous side bonds well to concrete or brick surfaces when set. It can be easily repaired or upgraded using existing cement products;
  
• Flexible-Concrete Cloth can be easily nailed through before setting. It has good drape characteristics, allowing it to take the shape of complex surfaces including those with double curvature;
  
• Strong-the fiber reinforcement acts to prevent cracking, absorbs energy from impacts, and provides a stable failure mode;
  
• Fireproof-Concrete Cloth is a ceramic-based material and will not burn;
  
• Waterproof-the PVC backing on one surface ensures that Concrete Cloth is completely waterproof;
  
• Adaptable-Concrete Cloth is currently supplied on 1.2 m (4 ft) wide rolls but can be manufactured with a roll width of up to 5 m (16.4 ft). The cloth can be produced in a range of thicknesses from 5 to 20 mm (0.2 to 0.8 in.); and
  
• Durable-Concrete Cloth is chemically resistant and will not degrade in ultraviolet light.
  
• Environmentally Friendly

Concrete cloth (CC) is a unique proprietary material. It is a time & material saving technique. It is very easy to place & handle. Concrete cloth is a flexible; cement impregnated fabric that hardens when hydrated to form a thin, durable, water & fire proof concrete layer. CC allows concrete construction without the need for plant or mixing equipment. Simply position the canvas & just add water. CC has a design life of 10 years and is significantly quicker and less expensive to install compared to conventional concrete. It is specially used, where the workmanship is very difficult. It is specially used in emergency works such as in military. 

References

• www.concretecanvas.co.uk
• www.concreteinternational.com
• The Journal For Science, Engineering And Technology In Wales, issue 62, winter 2009
• www.buildingtomorrow.co.uk