Instant Emergency Shelter, Just Add Water
section: Shelter | Design Revolution Today
http://www.concretecanvas.org.uk/

Designed by Peter Brewin and Will Crawford, Concrete Canvas has won 9
awards including the New /Business Challenge and Deutsche Bank Pyramid
Award. It is backed by the Selected Works Scheme at the Royal College of
Art. A patent has been filed. Crawford Brewin Ltd. is working to bring
Concrete Canvas to market. They are currently seeking financial backing
to develop the technology from working scale prototypes to fully
detailed pre-production prototypes, this will take 10 months from funding.

The Need
Concrete Canvas (CC) has 2 major advantages over tents:

    1. Operational: CC enables a hardened structure from day one of a
crisis. It provides much better protection in extreme climatic
conditions, better security against looting and enables otherwise
impossible medical procedures.
    2. Financial: CC has a design life of over 10 years, whereas tents
only survive for 2 years and must be replaced. Therefore, Concrete
Canvas is a one stop solution, saving effort and costs over the lifetime
of medium to long term operations.


Key Facts

     * Rapid: enables users to produce hardened structures within a few
hours, with
       comparable labour to a tented structure.
     * Insulating: the concrete shell has good thermal properties and
can be covered in earth or snow for increased insulation.
     * Durable: far more durable than tenting with a minimum design life
of 10 years.
     * Secure: provides a level of security not possible with soft
skinned structures, protecting stores and equipment.
     * Sterile: can be delivered sterile; allowing previously impossible
surgical procedures to be performed in situ from day one of a crisis.
     * Strong: the low mass and fibre matrix locked inside the concrete,
gives the structure good earthquake performance. The compressive
structure means it can also be covered with sand bags, earth etc. to
provide protection against shrapnel.
     * Semi-Permanent: provides all the benefits of a permanent
structure without the associated costs and time delays.

How Concrete Canvas Works

CC is a rapidly deployable hardened shelter that requires only water and
air for construction. It can be deployed by a person without any
training in under 40 minutes and is ready to use in 12 hours. The key to
CC is the use of inflation to create a surface that is optimised for
compressive loading. This allows thin walled concrete structures to be
formed which are both robust and lightweight. CC consists of a cement
impregnated fabric (Concrete Cloth) bonded to the outer surface of an
inflatable plastic inner. It forms a Nissen-hut shaped structure with
over 16 m2 of floor space, the technology can be scald to provide larger
structures. The stages of deployment are as follows:


Delivery

CC01 comes delivered folded in a sealed plastic sack. The dry weight is
230kg, an 8 man lift and light enough to be transported on a pick-up
truck or light aircraft.

Hydration

The sack is positioned and filled with water1. The volume of the sack
controls the water: cement ratio eliminating water measurement. The bag
is then left for 15 minutes while the cement hydrates, this is aided by
the fibre matrix which wicks water into the cement. Once hydrated, the
sack is cut along its seams it then forms part of the ground sheet.
Deployment is done at dusk to avoid over drying the cement.

Inflation

The structure is unfolded to form the shelter’s footprint. A chemical
pack is activated which releases a controlled volume of gas into the
plastic inner and inflates the structure.

Setting

The concrete cloth cures in the shape of the inflated inner and twelve
hours later the structure is ready to use. Doors and ventilation holes
are left with no concrete cloth bonded to the plastic skin this allows
access points to be easily cut from the inner once the cement has dried.

The fibres of the fabric form a coherent fibre matrix within the
concrete providing tensile reinforcement. This greatly improves the
composite strength of the shelter providing a durable protection with a
design life of over ten years. Because the structure can withstand a
very high distributed compressive load it is possible to pile snow,
earth, sandbags etc on top. This enables excellent thermal properties
and can provide protection against shrapnel, blasts and small arms.
Once CC has fulfilled its primary application as an emergency shelter,
it is highly likely that a secondary use would be found for the
structure. During field research we found a multitude of secondary
applications such as agricultural storage and accommodation. CC can,
however, be demolished using basic tools. The thin walled structure has
a very low mass, leaving little material for disposal.

1 Water does not need to be potable but must not be sewage or sea water,
volume is 120lts = 12 persons’ daily UN water ration.