The tent that turns into concrete in less than 24 hours | Hacker News Reader

The tent that turns into concrete in less than 24 hours

bbc.co.uk

259 pointsthekevan50 comments

I'm not sure I'm sold completely on the need. It's a very cool idea, to be sure, but I'm confused at the role it fills.

My knowledge of disaster zones is limited, but for military deployments - the other major customer - it's pretty in depth.

Here's the thing, there are two classes of structure, basically: Temporary and Permanent.

For a temporary structure - even longer term - a modern, modular tenting system (such as TEMS: http://www.mandbmag.com/tents/index.html) has this beat hands down in pretty much every way. Lighter, faster setup, faster tear down, adaptability, etc.

For a permanent structure, seriously? It would be much easier to build a traditional wooden structure once you've decided that you need one. You could even put the locals to work (which they would need) doing so. I find it very difficult to believe that anyone would want one of these dingy, musty things over a proper wood or concrete framed construction.

So where exactly does this fit in the spectrum? I'm not sure it does.

Keep in mind this is the first commercial version of the technology; I'm sure it will rapidly progress beyond dingy, musty blobs.

With the strength and light weight of the structure, along with the product's minimal cost compared to more traditional building materials and methods, I could see this being used to create very interesting and organic home designs. If the material is able to pass California building codes for earthquake preparedness, I could see people building whimsical temporary substructures, placing these on top and hardening them, then removing the substructures, enabling a much greater variety of possible forms. I could see doing something cool with stacked layers of bubbles and cut-outs for passages and windows.

Another interesting application for something like this would be structures on the Moon or Mars, if you could make the material on-site, or at least the heavy parts of it (cement and water).

You're not sure about the need for a sterile structure that can be erected in 24 hours, almost anywhere in the world?

I think he's suggesting that he's not convinced this is better than a tent for a relatively temporary sterile structure. I'm also not really sure what 'sterile structure' means in this context. I suppose it means it's very cleanable? Cause as far as literally being sterile.. these concrete tents have just been blown full of air, which presumably came from just outside.

In the video he said steralizable not that its already steralized.

You're aware that western military forces currently build entire trauma centres out of the tenting I described, correct?

I wonder if the sweet spot here might be the adaptability of the material. Maybe there are specific needs to quickly install structures of a specific shape/size where this material could be especially advantageous.

I agree. Quick, ugly and permanent are not qualities of a good solution to most problems, but quick, strong and pliable are. It looked fairly demolishable, too, so there might be something in using it for installations and wilderness construction. I'm thinking specifically about youth events - festivals and campsites. Basically, anything unique to the location that or that you'll be leaving unsupervised in a slightly hostile environment.

Difficulty in getting the materials to build a wooden structure to the disaster zone would make the concrete tent a better option in many cases.

This. I think the advantage is in ease of transport vs. wood and related wooden building materials. Furthermore, not every disaster site is going to have in situ wood on hand for building, let alone in a form suitable for any sort of ad hoc construction needs.

You both completely missed my main point.

You're aging the fact that these things provide better temporary structures than wood buildings, but as temporary structures, the current standard is modular tenting.

A good example of this might be Haiti. I believe there was very little wood around, which contributed the the crisis to begin with.

Again, the difference is that of the nature of the structure.

In a disaster zone like in say, Haiti, modular tents would outperform these things in every conceivable way, including survivability.

You don't even begin to think of rebuilding until months later. At that point, I don't think you'd want to make one of these your permanent home.

> I find it very difficult to believe that anyone would want one of these dingy, musty things over a proper wood or concrete framed construction.

Well, around here, wood-framed construction is only found in shantytowns. This would be a big step up, I think. And if you think it's easier to build a wood-framed structure than to inflate a wet bag, count me skeptical of your construction experience.

Thanks for sharing your thoughts.

At least it looks cool, organic and futuristic at as other posters already said. When I saw the video, the first thing that popped into my mind was: I want to use this to build a retreat in some desert in the middle of nowhere. Reminds me a bit of the settlements in Star Wars - A New Hope and those autarkic villages in New Mexico.

It would be much easier to build a traditional wooden structure once you've decided that you need one.

One of the problems Haiti has is that they have no more wood.

Have you considered price in your analysis?

Pretty sure fabric tents are cheaper in every way.

yeah, the company won an innovation award for it in 2006: http://www.trust.org/alertnet/news/concrete-tent-gets-mixed-... I guess it takes a while to productionize.

Thanks for posting this article. I was curious as to the cost for each of these as well as the mechanics of the delivery. It seems like a lot of people are asking the same questions. It's not an exorbitant cost, but ideally it would be a price where you or I could donate one in the event of a disaster. Still an awesome idea, though. I hope the team behind it gets the right support.

These guys pitched on the Dragon's Den (BBC's entrepreneur show), season two episode four, way back in 2005, and were turned down by some of Britain's sharpest business guys. Way to hustle getting this so far since then!

Was this featured on Dragon's Den (A BBC show were inventors pitch idea to investors) a year or more ago? I seem to remember someone pitching something very similar to this.

Yes I think it was these two.

Yes, I remember that. It was on season two, episode four, back in 2005.

I'm sure this has been worked out by the team, but I am curious to know more about the load-bearing nature of the concrete shell. I would imagine this is a very important consideration if it is to be used in post-disaster areas (i.e earthquake disaster areas where there may also be aftershocks). If, for example, the tent is not fully inflated before the concrete is added, would the hardened building be structurally compromised?

One of my mentors in Grad School (the late David H. Crane, FAIA), got a grant to design an emergency shelter right out of Harvard GSD. He and his team spent months designing a precast concrete building which could be deployed and erected quickly. At the end they did the economic analysis of the fabrication costs. The only place where it was economically viable to build it was lower Manhattan (this was back in the early 1950's).

This design suffers similar conceptual problems: diverting potable water to make a concrete structure when a tent would serve adequately - one of the biggest problems early in a disaster is providing potable water in sufficient quantity to maintain sanitation and provide adequate hydration for the local population and aid workers.

The water need not be potable. Maybe not a great idea for a drought/famine caused dislocation, but maybe for a flood/typhoon destruction of housing event.

The typically adverse effects of using non-potable water on concrete quality would seem to offset the sole advantage of the design over a simple tent - permanence. Flood events in densely populated areas (i.e. those most in need of large amounts of housing quickly) tend to produce particularly polluted water (e.g. Katrina Soup).

At 1:00 in the video they said that they could use seawater and could even work underwater but didn't mention that it had an adverse effect on the quality of the concrete.

Concrete ideally should have clean water for best strength, but it need not be potable. Salts, silt, organic matter, and small bits of trash all weaken the concrete to some, greater or lesser, extent. But the effects can be taken into account in the structural design. For that matter, there are additives that are commonly added to concrete under special conditions, for example to lower the freezing point in winter pouring, that also weaken it in similar ways.

Thanks for the clarification, I just don't know a ton about concrete.

I also know very little about concrete but I would expect that this construction varies slightly from traditional concrete due to the water being sprayed on the outer surface, rather than being part of the mixture. I could be wrong though.

And if the structure is going to be permanent, then using sea water due to a temporary shortage of potable water is going to result in a permanently weak building. I understand that this is supposed to provide a solid shelter during quick relief, but it's going to be much harder/costlier to take down than a tent if it becomes unnecessary at any point in the future.

What was it about lower Manhattan that made it the only place where it was viable to build the buildings?

I believe that was a reference to the cost of the structures, that they were so expensive that the only economical place they could be located was in areas of extremely expensive real estate.

I think the real innovation here is using an inflatable form. This could be cool with a spray on concrete too, like Gancrete: http://www.grancrete.net/videos/index.cfm#

A little off topic, but did anyone else not wait through the 30-second ad to watch the video? I find myself bouncing more and more on videos that do that.

Adblock Plus seems to be as effective for video ads as it is for regular ads.

Does anyone see how these sit on the ground? I don't see any footings in the video. Just compacted and graded topsoil? What is the floor made out of?