Tag: canvas

Concrete Cloth – Makes Durable Shelters Within Hours

By Anupum Pant

Today we have something which civil engineers would be extremely proud of – A recent innovation in concrete technology that has an immense life-changing potential – The concrete cloth; certainly a splendid engineering marvel.

What is it?

It is material which feels like a very thick canvas and has a three-dimensional fiber matrix. This piece of thick cloth is impregnated with a specially formulated concrete mixture. Once it is completely wet with water, it hardens into a thin, strong, fire-resistant and water-proof material, within a few hours. Commercial variants either have a hydrophobic coating on the outer surface or a PVC lining from the inside to make it completely impermeable to water.

Concrete Cloth

Since it just a thick piece of canvas impregnated with concrete, it can be transported fairly easily and can be made into various shapes to be used for different applications. For instance, it can be used for rapidly deploying hardened concrete shelters for people in need. It works like this:

  1. You carry a huge concrete canvas balloon with you in a truck.
  2. Place it wherever you need the shelter to be deployed.
  3. Pump water into it.
  4. Quickly start inflating it using a pump.
  5. Pull it around using, say a truck.
  6. Wait for it to harden.

Advantages:

  • To erect a shelter with concrete canvas, it only takes a fraction of the time taken to construct a shelter using tradition building techniques.
  • Unlike cloth tents, this one is extremely durable and can last for about 10 years. Moreover, it protects the residents from any form of extreme weather outside (Thermally insulated).
  • Construction material is light enough to be transported by a small pickup truck.
  • Requires just 2 people and can be deployed to a ready state within 24 hours – Within these 24 hours it gains about 80% of its full strength.
  • Can be tailored as required with the help of staples, cuts and nails / screws. In fact cutting it before hardening is not much different from cutting a thick piece of cloth.
  • Does not burn and is water-proof.

[Read more]

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Paper Bags Are Not Better Than Plastic Bags

By Anupum Pant

Plastic bags are terrible things. They choke animals, aren’t easy to recycle, do not break down, pollute our oceans, their production adds to our oil demands…and the list goes on. Some time back, we realized their ill effects and started taking steps that would encourage people to use bags made of alternative materials. Furthermore, several cities all over the world have banned the use of plastic bags.

Side Note: Interestingly, plastic bags aren’t actually banned for any of those reasons. They are banned because they tend to fly with the wind and move out of your trash fairly easily. They create a mess at places where they aren’t supposed to. That is the major reason as to why they are being banned.

In 2007, San Francisco banned plastic bags for supermarkets and pharmacies. Last year, it got expanded to all retail stores. Now, they have been banned for restaurant takeaways too. Also, the use of plastic bags at retail stores has been banned in several Indian cities. But the point isn’t to list out all the cities where it has been banned. There are many cities. I hope you get the idea…

When it comes to finding an alternative for plastic bags, paper bags seem to be the first choice. But it turns out, paper bags are not better than plastic bags.  Most of us underestimate their ill effects. Here are a few reasons that will make you realize why paper bags are not so good:

The point isn’t to make paper bags look bad or to make plastic look good or vice versa. It is to dispel the image of “the green paper bag” from our minds.

Reasons

Production: Production of paper bags all over the world involves cutting down 14 million trees every year. It is estimated that the production of paper bags creates 70 % more air pollution than plastic bag production.
Production of paper bags also results in much more water getting polluted when compared to the production of plastic bags. This is because their manufacturing process requires a lot of water.
Almost the same amount of petroleum used for plastic bags (for the material) gets consumed in making of paper bags to fuel the machines plus transportation.

Weight: Paper weighs a lot more than plastic. It is estimated that to carry the same number of paper bags it takes 7 times the transportation it takes to haul plastic bags. More trucks, more pollution, greater greenhouse impact.

Space: Paper bags occupy a lot more space than plastic bags do. This creates a problem at landfills that are getting filled to the brim already.

Recycling: Paper bag activists would say, plastic bags live for ever in the landfills. Yes they do, but there, paper bags do not decompose within a meaningful time period either. In fact, most of the stuff lives on for a long time in landfills. Landfills aren’t meant to make things degrade. With a paucity of oxygen and water in landfills, it is hard for things to decompose there. Even food items thrown away at landfills last for years.
That said, even plastic bags are almost never recycled.

Also they tear easily. As a result, more number of paper bags have to be used.

Solution

Both of them – plastic and paper bags – are equally bad. Recently developed biodegradable plastic bags are not any good either (they have a bigger carbon footprint). Carrying canvas, cloth or jute bags and saving them for future use is probably the best alternative.

If you liked this, you’ll probably also like – Understanding the Impending Helium Crisis