How To Make Roman Concrete

welcome to corporals corner today we're gonna explore the riddle of Roman concrete so stick around today I want to shift gears and try to revive some ancient technology now credit is given to the Roman Empire for the discovery of concrete or what we think of as modern concrete they had several different mix designs for different construction applications meaning the higher they built upward or vertically they use a lighter mix design versus say I want to build a bridge over a body of water I'm gonna go with a hydraulic mix that way it sets underwater their basic mix however was nothing more than lime mortar or lime concrete lime cement which is what this is right here and it was weather resistant and it actually got stronger over long periods of time meaning decades or hundreds of years so today I want to go ahead and go through that process let's get started the basic Roman concrete mix design consisted of volcanic ash limestone or shells and aggregate mean volcanic rock now a real quick way to tell with a knight you have limestone is that grass some household vinegar place it inside of an eyedropper and then gently drop it onto the stone if it fizzes up kind of like soda it has a good chance that's limestone so now you've collected your limestone and you determine to 100% that it is limestone go ahead and take all that limestone and place it into a campfire or a forge and you need to superheat it you want to heat it for good three to four hours until it glows red hot at this point the carbon dioxide is removed from the stones making them a lot lighter and there's our stones right there they're glowing too red want a fast-forward here about three hours you see it's glowing red still and as I mentioned before the carbon dioxide has been removed it becomes calcium oxide which will react with water there's your limestone or calcium oxide once you add water to it an exothermic reaction takes place it generates Heat if you notice the stones breaking down right here the slaked lime is what is called me add water to it it's slaked it's quick lime and it's being hydrated so it becomes calcium hydroxide and that's what you're going to use as one of your core ingredients for your concrete this right here is a small test you want to do it on a larger scale just remember once you add the water only add enough water to make it into a paste or a putty once it dries out it would light and fluffy and you'll add the rest of your ingredients along with water to create your concrete now for those who can't locate limestone another good source of pure limestone is the ordinary seashell I believe these right here are scallops just place them into a propane foundry Forge or even a campfire and superheat them until you notice the shells breaking apart or breaking down go ahead and remove them let them cool add water the same exothermic reaction takes place become slickline take that lime powder once it cools off add the rest of your ingredients the sizzling noise is because of the exothermic reaction taking place with the water the water is replacing with a carbon dioxide came from it's actually generating a lot of heat right now you can see the shells breaking down and forming that paste once that paste dries it will fluffing up I can add that to my volcanic ash and pumice all right I'm gonna get started there's our powdered limestone or our calcium hydroxide we have our volcanic ash and our pumice using my blender grabbed the volcanic ash and I blended it up actually rounded up pretty good if I wanted really fine powder here's our aggregates on the Left we have pumice on the right we have a volcanic tuff [Music] I'm gonna add my limestone powder first or my calcium hydroxide now the misconception is we're gonna think about this like modern concrete we're gonna dump a bunch of water in there big fat negative you want just enough water to create a thick paste what you're going for is you want to put the consistency of play-doh so keep that in your head you want play-doh real thick paste this sort of resembles drywall plaster Oh calcium hydroxide is good to go I'm gonna add my volcanic ash now real quick can we back up you want the ratio to be one to two meaning for every 1 pound of calcium hydroxide you want 2 pounds of volcanic ash so right now I added about 1 pound so it's a 1 to 1 then mix that up thoroughly keeping it in our play dough consistency now add my second pound [Applause] and last but not least our aggregate near our volcanic rock humus tuff etc and when it's all said and done this is what you're going for right here now you can see from that clip right there the concrete resembled play-doh I can work it in my hands and it didn't stick to my fingers or hands whatsoever so what the Romans did is they would take that play-doh concrete and they didn't put down a layer they would grab fifth sized rocks and those rocks could be ordinary rocks volcanic tuff volcanic rock pumice etc and they work it into that paste all the way down that line then they come back to the opposite end and grab some more of the concrete that resemble playdough and they'd put it across the top of those rocks then with special metal or wooden tools they would go ahead and it would force by tapping that concrete into the pores of those rocks all the way down the line and just repeat the process at this point right here we're pretty much good to go so they'll go ahead and fill up my concrete form I want to fill it up in two layers then I want to consolidate those two layers using a wooden tamping tool [Applause] [Applause] and when it's all said and done we'll go and finish it off now that's it for anywhere for 24 to 48 hours now let's go ahead and fast forward I allowed these samples to cure for seven days if you notice I'm scratching it I'm gonna hit it right here in a few seconds it sounds solid there's no damage occurring it looks pretty good to go now this sample right here if you notice you can see small rocks in there they're about 3/8 aggregate so I went ahead I replace the pumice with ordinary rock just see if there be any difference and to be honest they both came out exactly the same now this material is weather resistant but not waterproof if you notice you can see how porous it actually is all those bubbles where waters rushing inside that concrete now what they found recently is that the Roman concrete was just like this with the exception that they used sea water and the ocean water actually would soak into these structures and it would bond with the minerals and create new minerals and it would replace those holes solidifying it making a gigantic Rock these two samples right here have set for 24 hours and as you can see there's still no damage to them that's good to go in my book today's experiment was on basic Roman concrete or lime cement lime concrete what you see in front of you right here is my first attempt at Roman hydraulic concrete meaning it sets under water the downside of this it could take days weeks even months for it to fully cure so I'll keep an eye on this and maybe we'll do a part two if it works out welcome back that was outstanding success or failure you decide now along with that I'm in no way suggesting that this should ever replace modern concrete however with that said think about the big picture if you were in a long-term situation or the crap hit the fan it would be nice to be able to create building materials off the landscape say to reinforce some shelters just like humble opinion take your comments view support thanks for watching beyond the woods have some fun I'll catch you next time [Music] [Music]

Channel: Corporals Corner

Views: 2,191,727

Rating: 4.7668896 out of 5

Keywords: Shawn Kelly, Corporals Corner, Dave Canterbury, Roman Concrete, Limestone, volcanic ash, Pumice, Tuff, Sulfer, rocks, Concrete, Calcium Oxide, Slake Lime, Mixing, Sand, Construction, Survival, SHTF, Doomsday, Fire, Hammock, Camping, Hiking, Mortar, Bricks, Blocks, Roman Empire, Bronze Age, Bronze knife, Cast, Blacksmith, Bow Drill, Bow Saw, Buck Saw, Otzi, Axe, History Channel, Quicklime, Hydraulic, Survival Lilly, Get Home Bag, Primitive Technology, Lime, Clay, Kiln, Survival Skills Primitive, Roman

Id: tOhAfaFboNU

Length: 18min 45sec (1125 seconds)

Published: Sun Jul 30 2017

Reddit Comments

[u/lovesdogz]

That video was so much longer than it needed to be.

[u/quinnyfizzle]

I feel like the constant scratching of the surface with his finger nail was over the top and pointless but whatever lol

[u/bigboyg]

"As you can see, limestone will fizz when vinegar is added to it"

*drop of vinegar

*drop of vinegar

*drop of vinegar

*drop of vinegar

*sigh

*drop of vinegar

*drop of vinegar

*drop of vinegar

*drop of vinegar

*jesus fucking christ

*drop of vinegar

*drop of vinegar

*drop of vinegar

*turns rock

*well thank fu--

*drop of vinegar

*drop of vinegar

*drop of vinegar

*FUUUUUUUU--

*drop of vinegar

*drop of vinegar

[u/[deleted]]

"Then i'll use my wooden tampening tool"

pulls out a stick

[u/wordwar]

This really left me wondering how the Romans scaled this process up so they could produce sufficient materials to make their concrete.

[u/McCl3lland]

"You SEE?! It can even withstand the destructive force of my repetitive scratching! I have basically created a brick of diamonds!

BEHOLD! Never again shall our constructions fear the mindless pickings of drug addicts and fidgeters!"

[u/aazav]

Special pumice from local volcanos makes all the difference.

[u/0175931]

I'd love to see the compressive strenght of test cylinder on this. With at least 20 to 25 MPa that would be good.

[u/iandcorey]

"How to make roman concrete"

and

"How to ensure only half of your video is viewed"