Cement is the unsung hero of the modern age

www.popularmechanics.com...

Today, it seems as if we define civilization in terms of the small things, like decoded strands of DNA, splitting atoms and microscopic bumps on plastic compact discs. With a focus so fine, it's easy to forget the bigger, simpler things that got us here and continue to define our lives. Back up a bit and look at what the real world is made of. In there with wood, steel and glass you'll find another material quietly holding it all up. You'll find concrete—and, a lot of it.

I love building things out of cement like pots and pavers for my house.

Sometimes we forget about the wonder of cement. Like the article says. If you look around you will find concrete and LOTS of it.

Let's not forget this quiet, strong hero and let's send it to the moon and mars!

Thank you.

a reply to: HD3DSURROUNDSOUND

Concrete, the best was Roman concrete and it took a very long time for modern concrete to learn it's secret which turned out to be volcanic pumice, what made Roman concrete so durable and versatile was that it set under water and allowed the Roman's to build many otherwise impossible structure's, the Pantheon in Rome with it's huge dome is a prime example.
When the Roman empire passed away we in western Europe ended up sticking our hut's up with pig poo wattle and daub until these secret's were gradually re-invented and recreated and without it what little remains' of the Roman period would likely have been stripped away completely long ago as individual stone's are easier to re-use than massive pile's of concrete.

Don't forget about boilers.

a reply to: HD3DSURROUNDSOUND

Civil Engineers: We truly do build the world.

Oddly enough I watched a documentary about it and wow I did not know it drys underwater and when drying it isn't losing any water it is just changing it's structure.
I never thought about the stuff before but really respect the dude who invented it.

a reply to: HD3DSURROUNDSOUND

Concrete ROCKS! Pun intended..

I am in the process of building a brick house and have used around 20m3 of it so far for the foundation. At the moment, I am setting up the shuttering and steel reinforcement rods for three 5m cross beams, which will need another 1.5m3. I had the concrete for most of the foundation delivered and poured, but for smaller sections, including the cross beams, I just use a cement mixer. I can make around 1m3 of it like that in around 3 hours.

Concrete is much cheaper than steel, and can be made on location. This also avoids having to lift steel I-beams weighing 400kg into place. Lots of buckets to go into the shuttering though, but it's good old fashioned rewarding work. It's very practical that you have plenty of time to make and pour it, and after only a couple of days, it is strong enough to stack several tons of bricks on top.

But that's nothing compared to building something like the Hoover Dam (aka Boulder Dam). Check out this awesome documentary:

soulwaxer

While it does take a lot of energy to create (as in CO2 emissions) they actually discovered something else, all the concrete sitting out there actually acts as a carbon sink! The interactions with weather means that CO2 actually gets trapped on the exposed parts up to a certain depth.

Science Daily - Concrete jungle functions as carbon sink, researchers find

a reply to: HD3DSURROUNDSOUND

I remember having to clean (chisel) out the inside of a cement silo. Then we used to hand stack bags of Portland cement among other flavors. Good times !!

a reply to: testingtesting

It gets hard underwater because it doesn't dry, it cured. In water or not has no effect but should take longer underwater.

I'm a concrete carpenter in NYC, I do mostly commercial foundations but sometimes I do high rise. If you never seen a skyscraper go up you would be in awe. Many times we are on two-day cycles meaning we can erect an entire floor of a building and pour the columns and deck in two days. Every second day, a new floor. Crazy work.
We start erecting the next floor before the concrete is fully hard.

a reply to: HD3DSURROUNDSOUND

Great thread. I wish they would make our Cement roads pothole free.

If you concrete roads you likely don't have potholes.

But my lord are they expensive

Great thread and deservingly so. It was Henry Kaiser who figured out how to pour Hoover Dam as it had never been done before. One of the beauties of concrete is its life span as it slowly hardens. Roman concrete has lasted 2K years in places and is still strong. The machine age just meant we could really go to town with it. If we ever figure out how to polarize steel we'll really build some wild stuff. My best,