Chemistry of Concrete - Periodic Table of Videos

[SwingerJim]

A- concrete continues to harden throughout its life

B- you can pour concrete directly from the lorrie underwater, a boat launch is an example of this, water is actually used on factory floors to slow the evaporation and potential cracks.

[LasagnaIsGood]

WHY THE FUCK IS IT SO EXPENSIVE WHEN YOU WILL NEVER RUN OUT!?!

[sedwarg]

@LasagnaIsGood it's an expensive process to make it

[HKragh]

@LasagnaIsGood Let us say we found a way of utilizing the surface dust of the moon for building houses. You could still say "We will never run out", but it is still an expenssive process of getting the moon dust. So I don't see how the "we will never run out" is linked to the pricing in this case. Well, it sorta is. If on the same time it was a rare product, concrete, it would be even more expenssive :)

[Subparanon]

@LasagnaIsGood The answer to this is summed up in the beginning "You take calcium carbonate and you heat it up to create calcium oxide or lyme". It takes a lot of energy to heat up the limestone to the point where it becomes lyme. Energy prices are on the rise so concrete prices fluctuate with energy prices. Then there is the cost of moving a heavy substance to the place where it is to be mixed and then from there where it will be poured. Try shipping 100lbs of rock interstate.

[dbraven]

5. The reaction behind hardening of concrete is hydratation

6. Stirring the concrete mix slows the setting just a little bit by breaking up the crystal agglomerates

7. The main component of cement that slows the setting process is gypsum but it should make more that 10% of the cement blend mass, because it may cause false setting

8. In other words cement acts as a binder for the concrete mix.

9. Only entrapped air bubbles have a large negative impact on the compressive stength of concrete

[dbraven]

I love your periodic videos but as a civil engineering student I feel obliged to straighten few things out:

1. Cement is a mix of calcium oxide silicates; aluminates; aluminoferrites and gypsum

2. Concrete is a mix of cement, water, sand (fine aggregate) and coarse aggregate

3. Fine aggregate is aggregate with grains size ranging from >0 up to 4mm diameter

4. Coarse aggregate is aggregate with grains size above >4mm diameter but usually not more than 31,5mm

[Fermonos1]

"Which gets harder and harder, takes several days to get really hard."

[mumiemonstret]

The fact that the hardening is postponed as long as the concrete is stirred is very interesting and deserves an explanation. Are there more examples of chemical reactions that only take place when not mechanically disturbed?

[SEThatered]

I study architecture and despite a very broad and deep going lectures on concrete i have learned some things i didn't knew from this video!

Thank you!

[jurakas]

Thank you :)

[Hardy123Zhao]

"we will watch it coming out". lololo thats what she said

[aStrimbu]

He makes me so nervous in this video.

[nuzod]

i wish he would be my teacher

[ericsbuds]

I really admire the Professor for his honest approach to life and science.

[cuntylishus]

@SonnyTheWhiteDwarf I like the way you think.

[32582657]

This guy is really a great lecturer.

[Mojosbigstick]

To quote the chemically minded Spinal Tap

"Even the hardest concrete never quite sets,

And the Sun never sweats."

[soberek]

...in a hard hat, special gloves, periodic tie... Priceless.

[SmartNyc]

great interesting video

[atsf3780]

America: Truck

UK: Lorry

the differences are both numerous and funny

[mikeinsalaco]

another great video, I try to get my high school students to watch these, just fantastic

[petokyo]

In Japan, they would typically use a peristaltic concrete pump to get the concrete up there. But then, over here, greenness (sorry, "ECO") is a marketing fad to get you to replace your perfectly good telly/fridge/microwave/house/c­ar/wife/children/pets with new, more ECO friendly ones!

[daveduznotrull]

what about the Gypsum

[silverchill1]

you guys seriously need a show on pay tv's sciecnce channel

[silverchill1]

you guys need a show on discovery science amking and combining chemicals

[kolderiekerik]

All respect to the professor, but alpatranss is right!

"CaCO3, SiO2, Al2O3 and Fe2O3 are heated together at about 1400C"

Yes, and this heating process requires loads of energy. A significant portion of total energy goes to concrete production. Not exactly an almost infinite resource.

[boredomdisease]

i love these vids cause i then go to school and i look so smart in chemistry cause i listen to the professor awesome vids

[Bishn001]

nice tie

[Bimm3rcc]

Im currently making a project at my chemical engineering faculty. IM writing about a technology called calcium looping.. Where we from the cement plant can completely eliminate the CO2 emission by one simple way:

The limestone gets into the calcinator, making CaO, most of it goes to making cement/concrete as usual.

[Bimm3rcc]

@Bimm3rcc Then take some CaO and react it with the fluegas from the combustion that powers the plant, and exctract the CO2 from the gas by reacting it with CaO making CaCO3 (carbonation). Then we burn the CaCO3 and we get a pure stream of CO2 which then can be compressed and stored under the earth..

Make chemical engineering videos? :D

[alpatranss]

Unfortunately this video is full of misinformation. First of all it is not a simple mixture of CaO and SiO2, but rather the CaCO3, SiO2, Al2O3 and Fe2O3 are heated together at about 1400C, causing the formation of new compounds : alite - (CaO)3.SiO2, belite - (CaO)2.SiO2, and tricalcium aluminate as major constituents. It is the hydration of these new compounds which gives concrete its strength. The professor makes it sound like if you mix CaO and SiO2 with water you get concrete

[alpatranss]

@alpatranss But you'd get a simple mix of slaked lime (Ca(OH)2) and sand, which in time will react with CO2 , going back to CaCO3. This is actually used as a construction material, but it hardens very slowly and its ultimate strength is very poor compared to concrete.

[ib9rt]

@alpatranss "The professor makes it sound like if you mix CaO and SiO2 with water you get concrete" -- if you add the also mentioned aggregate to it I rather think you do. A good teacher is able to convey the essential core of a subject without getting the story cluttered up with pedantic detail. I think the professor knows this and he does a good job of presenting technical information in a clear and lucid manner.

[Toxie207]

@alpatranss Do not mock the professor. He is simplifying it for the masses. I think you just fancy yourself as a smarty pants! ;)

[ngneer999]

@alpatranss I also agree with alpatranss. Cement manufacturing is a solid state reaction between CaO, SiO2, Al2O3 and Fe2O3 at very high temperature. Alpatranss, did you work in the industry? I worked for Lone Star Ind. in Houston in the early '80s until they went out of business. I miss looking into the 500 foot long rotation kilns.

[gaussman08]

i'm so glad i found this channel omg i love you guys ! you should have a tv show :3

[onimotoko]

I've got a question for you professor, how did the ancient Romans know to drive out the CO2? Or rather how did they know how to make it in the first place?

[SomethinDwnUrPantss]

and now i know how buildings are make ;)

thank you very much

[ezwa29]

Cement hardening was the first chemical reaction they explained to us on chemistry lessons.

[aashish7kumar5]

One big loser whose brain is full of concrete dislikes this video

[captwasabi]

I've worked with concrete, on and off, for almost 20 years and had no idea of the actual chemical process involved. Thanks so much. One interesting story I do recall about concrete has to do with the construction of Hoover Dam. So much concrete was used that every 10 feet of vertical height a network of thin copper pipes were laid down and cool water ran through them. This helped quicken the solidification process. If they had not done this the core of the dam would still be soft. Wild!

[puncheex]

Cement is a fine grained powder of calcium silicon oxide, formed by burning lime and sand in a kiln and then pulverizing the result. According to a SciAm article I read long ago, when water is added to the tiny grains, the inside content of the grains is put under pressure, and breaks out of the "skin" to form long extruded crystals. These interlock the grains in a structurally mass and invade cracks in the aggregate. The sand added in concrete is just filler.

[citrinette]

Is there any way to download this video to show to a class of people? It is an excellent teaching tool!!

[coil311]

@citrinette

There are lots of "add ons" or extensions for Mozilla Firefox which let you download Flash videos. If you have Mozilla Firefox, go to Tools, Add Ons, Get Add ons tab, Browse All Ad ons. Then search for Flash video downloaders. There are many options, so good luck :)

[liquidefeline]

Did he say strings or springs?

[GRAHAMAUS]

@liquidefeline springs

[Rasayana85]

More videos like this. One person, in stead of five persons, talking for five minutes.

[seanmPWH]

Did he say the new building has a minaret?

[VileMike]

I like how he can make the ideas of watching concrete dry exciting.

[f60w]

great stuff! how about about plaster?

[AG2web]

youtube.com/user/ag2web

[satan31337]

you shoudl do somehting on welding electrodes liek 7018's or 6013's all the changes and end results are pretty cool

[WhichDoctor1]

If concrete is made from limestone, what is the difference between it and limecrete? I keep hearing stuff about limecrete, people saying that it is more eco friendly than concrete and even sequesters more co2 over its life than is used in its manufacture, wear as concrete is really bad co2 wise. But if they are made from the same stuff how can they be so different?

[stefanmckinley]

@WhichDoctor1 It's similar materials but a different process, limecrete is less "liquidy" when it is poured and the ratios of lime, aggregate, and sand are different... I think...

[richarddale76]

@WhichDoctor1

Also concrete has to be fired. this used alot of fuel in its manufacture

[Direkin]

If the university is so green conscious, why use heavily polluting Portland cement instead of eco-friendly geopolymers?

[richarddale76]

@Direkin MONEY!!!! Cost 50-70% more and in all honesty, its useless to work with. had uneven setting times and holds water for months. i use a "flow scread" on site and on a small 60sqmtr slab by 65mm thick took 4 months and £900 worth of dehumidifyers to dry

[o0oTheBeesKneeso0o]

Thank you for braving the heights to make your informative video - much appreciated professor!

[47f0]

Other concrete trivia - the bubbles aren't always a bad thing. There are several applications for foamed concrete - including at the end of runways, where some airports are laying an area of special foamed concrete that crushes under the weight of an aircraft, rapidly slowing it and preventing disastrous overruns.

.

Also, on large projects, the temperature of the reaction can be an issue - Hoover dam, for example, required over 500 miles of cooling tubing to avoid excess heat during curing.

[525047]

They need to make building out of a new stone type. You know play around with stone chemistry. Not because it would be better than concrete, just because we can. If all else fails, you could reinforce the building with steel.

[engelteir]

ive studied lots about concrete at university, good too see a video about it by you guys!

[ExpetimentalHomeLab]

Hoover dam, from Fallout New Vegas!

[RazielKain]

I always find it a bit funny how totally normal things like making a concrete wall becomes so much more interesting if you look at it through the eye of a chemist or scientist in general :)

[katmeow782]

What's the professors last name?

[KacelaJ]

@katmeow782 Professor Martyn Poliakoff

[katmeow782]

@KacelaJ Cool, I was just wondering because a guy at school looks 'exactly' like him. The hair and the face are as I would say, exactly the same. I was just checking incase he had a long lost son but it isn't the same last name ha ha.

[KacelaJ]

@katmeow782 Perhaps he's the professor's Love Child :p

[Intervene]

Awesome stuff. Thanks!

[exodia94]

the reaction between calcium oxide and SiO2 is part of the extraction of metals am i right? it forms the molten slag in the blast furnace rite?

[mopsnuf]

being green.. ew. I dislike anyone who uses that as some sort of commercial, as much as I like the professor. It should simply be the duty of everyone on themselves. Besides that: another great video, thanks.

~Nout

[riveness]

We might not run out of concrete but the energy required to make it combined with the energy supply challenge we have in the near future means that that will be an issue as well.

[kurtilein3]

@riveness

dont worry about concrete, its not that difficult, doesnt take that much energy. compare it to aluminium, or steel, or plastic, many ores take incredible amounts of energy until you have the final product, some (like aluminium) involve electrolysis. and plastic still contains all the energy of the oil, and is completely dependent on crude oil. maybe you could get the energy for all concrete on the planet by burning all old plastic on the planet.

[jacksawild]

@riveness The Romans seemed to manage using good old human energy.

[riveness]

@jacksawild And a much smaller population.with a small few living at a good standard of living (for the time) and less power hungry technlogy.

[culwin]

These videos make my day

[YamiPoyo]

Do a video about his lecture plz.

[paronfisk]

A friend got a chemical burn on his butt when he sat on some wet concrete.

[puncheex]

@paronfisk: Yes, the lime is a violent desiccant - it pulls water out of almost anything to create calcium hydroxide. That is essentially a burn. If unmixed lime is left on the surface it can cause such.

[hobomnky]

wont the calcium oxide turn to calcium hydroxide cuz of the water?

[vlvl21]

Can concrete be recycled???

[killman369547]

@vlvl21 yes it can demolish buildings which have concrete in their construction are recycled all the time the debris is ground up to the proper size and can be used as aggrogate for concrete in new buildings in fact the next hirise or basically any building you walk into there is almost certanly recycled concrete holding up the building or in the foundation or both

[Zaddtheman]

I thought global warming wasn't in vogue anymore... huh.

[viper100200]

@Zaddtheman Most of what the professor means when he talks about green chemistry doesn't even have to do with global warming. It's finding new ways to do reactions using less volatile chemicals or in this case eliminating unnecessary waste.

[Ritzoid]

Love how you guys keep chemistry and your videos interesting

[rowflowers]

awesome

[Digeridude]

Does the aggregate serve to deflect forces like a tube filled with ball bearings?

[Phage0070]

@Digeridude

Not really, the aggregate is basically just a more sturdy substance which the concrete can hold together. This makes the concrete structure overall more durable.

[JohnnyTsu228]

You should investigate the concrete process used to create the Hoover dam in the US. They have some interesting figures as to how long it would take the concrete to cure if they poured it all at once. I believe it was 180yrs+. There was a special process used to cure it because of the quantity that was being used.

Also, when concrete cures, reacting with CO2, it is also interesting the amount of C02 that the concrete actually absorbs throughout its lifetime--I THINK it 80% absorption.

[IsboPirate]

One of the greastest invetion of man :D!. Thanks for this video.

[o2me2]

Thumbs up. Very informative. Thank you.

[TomMarAlem1987]

Last century the paranoia was about Global Cooling, the Earth moving toward another Ice Age. This century the paranoia is in the opposite direction, the Earth turning into a desert. The question to be asked is who is making money from the paranoia and from promoting it? How many scientists will not get funding for research unless and until they connect the work they want to do with Global Warming?

[TheBetterGame]

@TomMarAlem1987 oh give it up already. there was no "global cooling" paranoia. There was one, easily rebuked, paper, in the 60's, which has gotten more press time in the last 10 years than it did in the 30 years preceding it.

[oisiaa]

It is always a pleasure to have one of your videos pop up in my subscription box! I love it!

[johngorgis]

Professor,search{ 2012 enigma }on youtube

[TheNinthWorld]

You guys should talk about the chemical structure of diamonds and explain what makes them the hardest known material on Earth.

[bluepastel]

@TheNinthWorld

I think they already have. Take a look at their videos on Carbon.

[TheBetterGame]

@TheNinthWorld Agreed!

[tybo09]

How did you get any work done with the building going on right outside your window? I had to cover the window in my office when I was an undergraduate because there was a giant tower crane across the street and all I could do was watch it...

Proof I got older in college but never grew up.

[sonicssidekick]

@tybo09 I don't know why, but your comment made me smile.

[mathiaspaul1987]

I don´t think that the CO2 that does come from the concrete industry will cause such a problem, because when the concrete or the cement is used it will bind the same amount of CO2 back over time.

Or am I wrong?

[Chaosblade777]

@mathiaspaul1987 I don't imagine concrete binds nearly the same amounts of CO2 as are released into the atmosphere by industry, which are probably, unfortunately, much greater due to the large-scale chemical reactions done there compared to the gradual one done by concrete.

[AlterGX]

@mathiaspaul1987 It may absorb the same amount, not fully sure, but the amount of time to absorb co2 vs how quickly it's released is not in the globes favor.

There are some cements are that absorb co2 to set like Eco-cement, ie it requires co2 to set.

[mathiaspaul1987]

@AlterGX & @ Chaosblade777 you are both right. I ignored for a moment that you need to heat the CaCO3 and that the amount of Energy needed for this is most of the time gainded by burning fossil energies. But what if I would say that I use wind, solar, water or atomic energy for it ^^

[BasherCoon]

The sorry-faced, begrudged-looking supervisor at the beginning of the video didn't realize that thousands of people all over the world would soon be seeing his company's logo, more than he could have done for his company no matter how hard he tried.

[JimPrower]

When I was Bradley university about 6 mos. ago (graduated! Yay!) I saw a lot of construction work, and a lot of Concrete. Nice vid.

[cloudftw93]

NEVER forget the periodic tie!!

[lepthymo]

these vids are nauseatingly interesting

[LNOL]

Haha the "lorry."

[puretroubleman]

@LNOL yes we call trucks lorries the legal name is LGV (large goods vehicle)

[jfn1103]

hard hat, special gloves, and a periodic tie. my man

[eveplayer12]

love these vids!

[thisusersuck]

ntu is greener :)

[Nanovirus5995]

Haha! Periodic tie! Thats Definitely the most important part of Any construction site! I Love the professor! Keep these videos coming! They are Fantastic!

[gematt7]

i studied all this last year :)

[nishbrown]

Glad I don't have to do that work any more.

The Professor sleeps in that tie, doesn't he?

[Osmfaec]

0:12

Are those rubber boots?

Forgive me, but aren't steal toed boots required on a construction site? Or is it different over there? Or maybe they are steel toe but it just doesn't show.

[shahared1]

@Osmfaec I work in a factory and can tell you that steel toed footwear now comes in a large variety of design. You can purchase steal toed tennis shoes that are indistinguishable from their normal counterparts, as well as rubber boots and rubber slip overs for normal shoes.

[WhichDoctor1]

@Osmfaec I have a pare steal toed rubber wellies just like those.

[shintsu01]

maybe its interesting to use concrete that is not required to use a lot of energy to create (heating it up on production) i have seen a TED talk about it once

[thefranciswatts]

The steel doesn't just increase strength, it is specifically added in areas where tension forces will be present. Like he said, concrete doesn't work well in tension. But steel does.

[seahawk124]

And that's not the first time I've seen a poker vibrator.

Make your own jokes people.

[dd08880bb]

I love these videos :D You are great!

[CarlEldar]

Imagine the Professors helmet hair after taking off the hardhat!

[panchoxpanchox]

I love concrete... yeah!!

[rs666sathan666pk]

Did you need a haircut before fitting in the helmet? :)

[MrTaurentino]

does the university have a biology channel?

[DidntKnowWhatToPut1]

@MrTaurentino I don't think they do yet.

[kaczmarek3007]

Their are no dislikes yet, but who ever does dislike this video cant afford a house.

[jjkul1]

"Sorry, Prof. We just don't have helmets that suit your hairstyle. =("

[dreadpiratedan]

poor guy, he looks absolutely frozen. thanks for doing this prof! :)

[pompeyjim12]

Sorry, but if it takes several days to get hard, you have to see a doctor...

[swcnut]

@pompeyjim12 LOL good one

[ErtyDaSwe]

@pompeyjim12 He did say that the concrete that was made a day ago before this clip already was hardened, but what he meant was that concrete uses several days to get real hard.

[sorrysonofa]

@pompeyjim12 but it gets harder and harder, the romans have it really hard by now :)

[ConnorXV]

not green, grey!

[ConnorXV]

@ConnorXV and have you got the video for this concrete sodium reaction?

[DeoMachina]

Laying concrete used to be my job...does anyone know why it gets so after it hardens?

[DeoMachina]

@DeoMachina why it gets so hot*

Sorry I messed that up lol

[Arkalius80]

@DeoMachina The reaction the professor talked about is exothermic, releasing heat. Plaster of Paris is the same way... I remember reading a story of a person who submerged their forearm in still-liquid plaster of paris and ended up suffering severe burns as a result.

[jakeweiq]

@Arkalius80 so say... if someone so unfortunate enough to get buried alive in a concrete mixture, he will be 'burn' alive before even the concrete harden and suffocate him...... rite?

[JehuMcSpooran]

@jakeweiq Doubt it. Suffocation/drowning in concrete should happen before you would get burnt. 

[Arkalius80]

@jakeweiq I don't know if they'd burn alive... they'd probably die of asphyxiation before the heat caused them significant harm, but I'm sure the heat certainly wouldn't help preserve the body. I don't think concrete produces quite as much heat per volume as plaster does.

[njimko23]

@Arkalius80 - That was probably a chemical burn, not a heat burn. Liquid cement has a ph of about 13.

[EruIluvatar]

keep it up professor

[coolliger]

kewl

[30LayersOfKevlar]

The Professor makes even the concrete fascinating.

[prospero021]

That's one big vibrator!

[nobreakpeter163978]

i pass there all the time .i wish i could get in as i'm civil engineer student , want to get experience from that.

[Dan4157]

Great video as always :D

I'm being picky here, but "sand" only refers to grain size. However, sand is mostly found as SiO2

[Zeldakitteh]

Having concrete examples while explaining makes the video interesting.

[VulgarityDivine]

Stopped at 2:35

[MonsterLopes]

Got stuck at 1:09 for me

[SOAD861]

These videos are fantastic

[chillz27]

@kmohammad2 yay!

[leungclj]

@kmohammad2 not quite =P

[Jaskarsis]

@kmohammad2 nope sry :D

[Arthur61987]

@kmohammad2 Negative :)

[Jaskarsis]

woohoo nice vid!