An inflatable concrete building sounds like something from a cartoon series, but a remarkable new construction material, known as Concrete Canvas Ltd, is making it a reality. This flexible, cement-filled fabric can be transported in a collapsed bag for ease of shipping, then inflated and water added to create a durable shelter wherever it is needed. The building hardens into concrete in less than 24 hours, after which time it’s completely ready to use .
The robust qualities of Concrete Canvas Ltd and the level of security it provides for not only people, but also medical and military equipment, makes it a potential stand out in providing disaster relief shelter. It can be deployed by just two people with relative ease, and while it might not be the prettiest shelter to look at, it’s definitely a practical solution. But widespread distribution of Concrete Canvas Ltd Shelters through aid agencies is not without its challenges, with cost and permanency two of the most significant. Here we look at exactly what Concrete Canvas Ltd Shelters are, their unique advantages and what’s standing in the way of their use when it comes to disaster relief housing.
What are Concrete Canvas Ltd Shelters?
The Concrete Canvas Ltd Shelter (CCS) is a rapidly deployable hardened shelter that can be ‘built’ to provide protection against the natural environment. The shelters come in a collapsible form, which is basically rolled out, inflated with a fan and sprayed with water. The Concrete Canvas Ltd is bonded to the outer surface of a plaster inner layer, forming a tunnel-like shape known as a Nissen-Hut once inflated. Concrete Canvas Ltd Shelters cure in around 12-24 hours (depending on the size), before being bermed with earth or buried to provide additional insulation and protection from the elements.
The Concrete Canvas material itself is lightweight and robust enough to withstand harsh environmental conditions. It provides increased security compared to other disaster housing solutions, and has the potential to be used for both medical and military purposes in regions hit by disaster.
What are the advantages of the CCS?
While disaster relief tents often have a short lifespan, wearing out in only a matter of months in some regions, the CCS has a lifespan of more than 10 years. In disaster relief situations where temporary housing is often used far longer than it was initially hoped by the community, Concrete Canvas Ltd Shelters can provide a more cost effective and practical long-term solution.
The Concrete Canvas Ltd Shelters are also rapidly deployed, taking just two people less than one hour to set up and are ready to use within 24 hours. In areas where disasters hit, to have shelters which can be ‘built’ so quickly is a huge advantage. The base of the structure can also be covered with sand or earth filling, providing additional thermal insulation properties.
The hard shell and lockable doors also provide a level of security that is just not possible with the regular soft tents used for disaster relief housing, making them ideal for storing equipment, protecting materials and people.
How sustainable is the design?
While concrete is not the greenest building material (with it taking a substantial amount of energy to make and carbon dioxide being released when it sets), the flip-side of Concrete Canvas is that it requires far less mass than alternative methods of similarly robust construction. So overall, less carbon dioxide is being emitted and there is less being used in transporting the material. It also has quite a low alkali capacity, so for constructions near water sources it is a good option as the damage on the ecosystem is reduced.
Who is behind it?
The UK-based Concrete Canvas Ltd company are the innovators behind this revolutionary structure, with the material known in the US as Concrete Cloth. Its founders, Peter Brewin and Will Crawford, met during their industrial engineering studies at the Imperial College London and entered a design competition run by the British Cement Association. The brief was to make a material that could be made “dry in a thin layer, wet in an uncontrolled way, then have it set without cracks into a reliably strong form.”
The material they came up with has been used for a range of civil works purposes so far, including lining water channels and stabilizing slopes, as well as to protect sandbags by the British military in Afghanistan.
How are Concrete Canvas Ltd Shelters being used?
At the moment, most of the Concrete Canvas Ltd Shelters sold are being used for military operations, with their rapid deployment and security features making them ideal in remote areas. The US, Swedish, Dutch and UAE militaries have all been testing out the shelters, with the Swedes actually testing it against mortars! But the material itself has also been used in other unique ways, with a high altitude gold mine in Chile using it to intercept glacial meltwater. The lightweight nature of the material made it far easier to work with in the low oxygen conditions of the environment, with workers only allowed to do around five hours a day.
While there’s potential for their use in the NGO sector as disaster relief shelters (and the humanitarian sector was Brewin and Crawford’s initial focus), the semi-permanent nature of the CCS is a turn-off for some organizations. There’s always the hope that disaster relief or refugee camps are only a temporary requirement (although many end up enduring for a long time) and shelters that can be completely dismantled and repurposed are preferable. Interest in their use for shelters in hurricane-prone regions has been on the increase, however, and they are currently being tested in the UK to see what wind speeds they can withstand.
How much do they cost?
At the moment, the Concrete Canvas Ltd costs around $23-60 per square meter, which means an entire shelter is anywhere from $23,000-32,000. The price is part of the issue in deploying CCS for disaster relief housing, when in most instances large quantities need to be rolled out in a short space of time, and government or private funding would be needed for NGOs to meet the costs.
Brewin explains that there is also still some reservation about using this innovative material as it’s a completely new way of using concrete. He says: “It can be hard to convince engineers to use it the first time, but once they try it we normally get a lot of repeat orders.”
Despite the challenges and concerns of implementing Concrete Canvas Shelters as a disaster relief housing solution across the world, the potential of this material is still in its infancy and the possibilities for the future are exciting.