Instructables

Make Cement From Scratch?

I have spent a great deal of time working on this question yet, I have no solid answer to go on.  I tend to enjoy acquiring a skill set which would be very useful come TEOTWAWKI (the end of the world as we know it).  I am far from a prepper, however I still entertain a slight possibility and see no problem with learning how to do a little more than cope. These skills extend from knowing where to grow, gather, and how to store penicillin to simple things like a yeast starter 100% from scratch.  Brewing and distilling are also handy because it makes a great trade item.  These are all things you never see in the Walking Dead or any other TEOTWAWKI cinema.  One of the more important skills I believe would be conjuring fortress walls from rocks in the form of a little thing we know as concrete which we all take for granted.  Now I could mix portland cement and filler with some water all day long and make a pretty cool fortess, but seriously.  All the home depots in my state wouldn't have enough quick rite for that.  So today I wan't to know what general rocks and minerals (that you can find in nature) can you combine to make cement.  I know there are all kinds of fancy names for these, but what I really need is some good old generalities.  Tell me to go outside grab a handful of clayish dirt, but it in a kiln with some lime and grind it up.  I'm not looking for top of the line stuff here, this just needs to be able to hold a general form for a few years and be a little bullet resistant.  This is for a crude fort, not the tallest building in the world or the hoover dam.  A simple mortar would also be nice, although there really aren't any stones around to put together, bricks aren't super hard to make with as much clay as we have in our soil. So join me and maybe I will put together an instructible on all the skills you actually need but don't have!

RavensCraft11 months ago
Compressed Earth Block  is probably the easiest  way to make something 
similar to what you have in mind.
http://en.wikipedia.org/wiki/Compressed_earth_block
jj.inc (author)  RavensCraft11 months ago
I hadn't seen these before and I love this idea! I imagine you could mortar these into a meter sized cube and then place it to make a very strong wall. Thanks!
Kiteman11 months ago
In a TEOTWAWKI situation, forget cement. The raw materials are heavy to transport, and take a lot of energy to process (at a time when fuel will be in short supply). Instead, learn "native building" skills.

Humans have built from local materials for a lot longer than they have used cement (and, yes, I know the Romans used cement). 

Learn dry-stone walling, cobb, wattle and daub, timber-frame, turf. Look to iron-age techniques, where homes were not built up, but dug down (dig a big hole, pile the debris around the hole to raise the wall, then add a roof). 
jj.inc (author)  Kiteman11 months ago
As it turns out there are tons of natural gas wells around my area which could provide endless fuel because they don't need much maintenance and the pressure alone pushes the gas to the surface. I live in the middle of nowhere and I really like the ideas of these natural building materials, but concrete would be invaluable in a TEOTWAWKI time. I have looked at CEBs, but you must individually place each block (tons of labor), it also doesn't have the sheer mass that concrete does. You could drive a truck into a concrete wall and it wouldn't go through, these other materials just don't have those properties. I have seen plenty of vehicles go through brick walls in our town, however I have seen many cars murdered by concrete. Now a hybrid is seems like the happy medium. An center wall with metal reinforcements inside made of cement and then surrounded by organic building materials would be extremely effective. The organics would slightly absorb impact and disperse it into the concrete which even in extreme cases would have re-bar to act as a kind of net. The main problem I am seeing is that we aren't fighting Spartans anymore, we are fighting off people with extremely well equip vehicles for entering a base. Thank you very much for your input, as always it was very helpful
Kiteman jj.inc11 months ago
Look at the aftermath of any major disaster - the victims can do nothing until the very basics are fixed, and that doesn't happen until folk from outside the area come in to help. Even with major help from unaffected nations, it takes years before anybody can think about anything other than the very basics - finding food, safe water and enough shelter to keep the weather off.

Come a real End, forget about armoured conflict*, forget about defensible compounds, it will be years, decades of starvation and disease before folk have the time or energy think about frivolities like concrete.

*Most armed forces only have enough fuel and ammunition for a week or two of sustained action before more has to be manufactured and shipped in. Any group cut off from base by The End would only have enough gear for hours, maybe only minutes, of sustained combat before being forced into hand-to-hand combat.
My ex-military landies had an expected life in combat of two weeks too. They're now nearly 40 years old !
But without the fuel, they're just big green bricks...
Maybe the tank was a two week tank - it was big enough....

Steve
mpilchfamily11 months ago
You need sand, lime, water and an aggregate to make cement. Now if you mix some red clay with straw and water then you pack it into a tight form and allow it to either kiln, fire pit dry or let it sun dry. Sun dry isn't as strong but you can build a structure from it easy enough. But why start from scratch when you can scavenge from your surroundings.
jj.inc (author)  mpilchfamily11 months ago
Do you have ratios on those?
Vyger11 months ago
Did you know that there is all kinds of evidence that the stones of the pyramids were poured in place and not hauled up ramps like most believe. Unfortunately they have yet to figure out how the mix was made although they have found lots of hair, both animal and human inside the rocks. How could they have developed a process that turns a slurry into solid stone and kept it secret so that it died with the ones who developed it?
People figured out all kinds of things in the past. Some discoveries have endured and turned into common knowledge. Some have disappeared waiting to be rediscovered.
Check on Wikipedia for info on the process of making cement.
rickharris Vyger11 months ago
Looking at them from close up - and I have - they definitely look to be hand hewed from solid stone.

Cement isn't all that easy to make on a small scale - You need to bake limestone in an oven for several days, add water, sand to the resulting material to make morter

http://en.wikipedia.org/wiki/Cement
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