Using Liquified Nitrogen to Cool Down Concrete

This sounds like a good recipe for concrete foam.

No. Not unless you put cooling tubes in the concrete and leave them there.

How else will you remove the heat?

Indirectly.

Spray chilled(somehow) water on mixing drum

Where to get water from a moving vehicle?

How to dispose it?

Additional load to the vehicle?

This is done every day here in the USA, with no difficulties.

Where to get water from a moving vehicle? A truck mounted tank.

How to dispose it? It evaporates.

Additional load to the vehicle? What's another 200# to a vehicle with a GVR of 80,000,000 pounds?

Watch out for the decimal point police! (An internal coup d'état from LynDoor Industries™.)

We make 'em BIG in LynDoor™ land!

OK, how's 80,000 pounds sound?

Very Much.

Good idea

Could you send us some photo about such a vehicle to share?

Your problem isn't cooling it down...
It's stopping it getting hot in the first place.
All to often we see people trying to solve symptoms instead of the actual problem.
Like I often say. Solving problems is easy, the hard thing is identifying the actual problem.
Del

As usual with Del- he goes on to prevent the disease in the first place --.

Yes there are ways to do that . Why Cryogenics and hazards -and costs?

Do this way :

http://www.elkem.com/Global/ESM/support/technical-papers/concrete/concrete-applications-Low-Heat-Concrete.pdf

Could you help me to find out any paper or document related to the adverse effect for post-add nitrogen.

As the cost of nitrogen will be incurred to the supplier if they cannot control the temperature at delivery. I just want to know how the quality problem is.

Hopwever, there is increasingly popular of using liquified nitrogen. The reply here just make me surprise.

From the picture, they use a big tank for nitrogen storage.

Is it possible to use a portable container? How much it is required for a truck of concrete?

Will adding ice cubes into concrete solve the problem?.

Tell us more about your problem, is it, 115 degrees in the shade, while raining? Lol, is it a long drive from the plant? Is the concrete truly to "hot" to work with, or are you trying to meet an engineers spec sheet? Ice cubes is probably not a great solution the sheer volume of ice cubes you would need to use to affect the temperature to any significant degree seems prohibitive, also without knowing how much extra water those ice cubes are going to melt back into, you could easily over saturate the mix, making it useless, either from an engineered mix stand point, or for real, if you had say 8 or 10 yards in the truck, and those ice cubes melted into 100 gallons of water, you might as well dump it out and start over, some engineers are very picky about how much water you can add we have had had them try and reject trucks that had more that 20 gallons in them over all

Where ice is added at the time of batching the ice is part of the total water content not additional to it. The ice needs to be fully melted in the delivery truck's drum and mixed through prior to dispensing.

ya that dawned on me a little while after i posted, i dont know why i didnt think of it before opening my big mouth lol, its an interesting idea, in Texas in the summer they would either move the material indoors or soak the rock and sand in ice cold water, or cover it with white tarps and spray it down with cool water, i wonder if they ever tried this method? How do they meter the ice when batching? So as not to end up with to much water after it has mixed? Im assuming just some guy with a calculator figuring up how much water they have used to make (X) amount of ice, 50 pounds of ice = (X) amount of water?

50 pounds of ice = (X) amount of water?

50 pounds of water, 8.344 lb=1gal @ 32F

In this case, the moisture content of sand and aggregate will be increased sharply.

You need to recalculate the amount of water adding and the answer become not very accurate

Add the water + ice based on their total weight (mass) and the correct water content can be achieved.

This is that 60MPa job you mentioned in your other post right?

What sort of volumes are we talking about?

Although at the time i posted, i was assuming he meant he wanted to add them at the site, not at batching.

I'd avoid nitrogen, keeping the temp in a range you want would be tough, nitrogen boils at a VERY low temp, you'd have a hard time with "fine control", I think you'd loose several batches and have a lot of hardened concrete you'd be tossing,

how about running some cooling tubing-hooked to a storage tank you can fill and refill with chilled water? I'ts easy to meter flow and n one will freeze their fingers after trial and error you'll know how much water and just how chilled it needs to be per given batch

As was already stated details would be helpful, however, there are a few things you could try that dont involve cryogenic liquids lol, the concrete supplier could work on his end to keep the material used in the batch at a lower temperature, cover the rock and sand with white tarps, and soak them down with running water, they do that in places like texas to keep the material cool, that translates into more travel and working time before the concrete starts to set, they could also try keeping the material indoors and out of direct sunlight, and keep it cool that way, as several others have stated, liquid nitrogen freezes things on contact, frozen concrete wont set up correctly, your end product would be unreliable at best, your other option, portable batch plant and materials on site, gives you more control, and can be batched only minutes before use, instead of half an hour or longer in some cases, also, you could saturate the rock and sand directly with cold water, the chilled rock would act as a retarder, and keep the concrete cool longer, there are several chemical options, retarder's plasticisers and such to slow down reaction time, but ice and liquid nitrogen seem like a poor choice, can you tell us the location and enviorment your working in, is it absurdly hot, or simply a long trip from The plant, these things matter.

2 possible non-nitrogen solutions;

1) Transport dry mix in concrete truck, add water at optimum time.

2) Spray water on outside of drum during transport, cooling effect will depend on concrete temperature and humidity of air ( & how fast truckie drives)

Transporting as a dry mix and then adding water at the site may not be possible as it would mean excessive down time for the concrete trucks. They would be sitting idle at the site instead of returning for more concrete. Other than that, it sounds like the best solution; mix at site, allow to cool down, then pour.

Ron,

Concrete doesn't cool down till long after it is poured and solidified.

"Transporting as a dry mix and then adding water at the site may not be possible as it would mean excessive down time for the concrete trucks."

That's why I said optimum time - at some point on the route, start adding water and mixing. Perhaps best started on advice from site as to what time they will be ready for pour.

When a large dm was being built in India, a similar problem was seen. They used crushed ice instead of water to mix with the concrete. This kept the mix cool till delivered to site. The dam was built in the fifties and still going strong. The technique seemes to work.

When they built the Hoover dam,they had an ice making plant at the work site(from Discovery channel?)

actually... I visited that dam years ago with a GF I had at the time. I was so impressed I bought a book on it's construction. a year or 2 later an old ME friend and I took a trip to Vegas and included a side trip back to the dam to check out some of the engineering. (ok I'm a nerd at times) there's a myth about people buried in the dam. TOTALLY FALSE yes they were in a rush but no one fell and is entombed within the dam. they used a process known as a "continuous pour". in order to do this they installed piping with each new forms the dam grew. cooling water from the river was drawn into an onsite cooling plant to lower the temperature of the water before it was circulated through the piping. once that section cooled and hardened the pipes drained and a mortar was pumped into them and they were capped and are still thee today as part of the structure. there was no use of ice

The temperature rise may be due to exothermic reaction of the concrete mix during transit stage of transportation.The vibration of the vehicle & rotary mixing can also accelerate the heating up reaction. If pH control can help you ,can add Liquid ammonia to the mix in feeble quantities, which will get released out during curing stage. Other wise urea should also does the same job & decompose later.

Other simple device could be air or water tubes fitted to chamber which circulate out coolant fluid.

Contact ice bar / cubes with wood powder to the exterior of the vessel again is cheap idea.

I am not a concrete man, but post only a suggestion coming to my mind.

"The temperature rise may be due to exothermic reaction of the concrete mix during transit stage of transportation."

Also during curing, or moreso, methinks.

Yes, surely. Thanks for the addition.

Does this phenomenon affect concrete in cold climates or in winter?.

If it has been mixing too long, it does. But most of the time in the winter, we were worried about the concrete freezing before setting. We could only pour when temperature was 27 F and rising and we would use hot water and accelerators, a lot of times it was calcium chloride.

I see many answers to techy questions that I disagree with in part, that get a thumbs up. Others with really good answers that are not rated as high.

This question is a simple chemical reaction question. Cooling concrete in the mixing drum with anything except ice or designed chemicals that slow the chemical reaction is hazardous to the final product.

Your actual good answer is; start the chemical reaction as close to the point or time of use as possible. The concrete as dumped into the mixer drum, can sit in the drum for a very long time, you do not have to spin the drum at all before you arrive on site, if you do not start the chemical process by adding water to it.

Concrete failure is most common if concrete freezes, or is placed after the actual chemical curing process has already started, which is indicated by the temperature of the concrete.

Save your money on the liquid nitrogen and mix the concrete just before it is ready to be placed. Just like you would use any two or more part chemical reactive process.

Dams and other massive structures have to consider the mass process, That mass contains heat, again just like any other chemical process, you can expect much faster reactions when mass is involved.

Additional water added to a concrete mix after the time of chemical reaction is detrimental to the design strength of the end mix. Not a good thing at all.

PLEASE CR4 bloggers - have a deeper look at the link I sent with#7 . That is the complete solution.

IIRC, Grand Coulee and Hoover Dams were cooled by chilled water through pipes embedded in the concrete. Other dams have been cooled by flake ice mixed into the concrete. One of the Brazilian dams had an ice plant of twenty machines collectively capable of making 600 tons of ice per day.

When they built Bolder Dam, they ran pipes through the concrete and ran cooled water through. Using liquid nitrogen could freeze the concrete (not a good thing).

your post made me chuckle. there is no Bolder dam! Hoover was not such a loved guy at the time and a lot of people hated the idea of naming such a grand project after him...hence the "Bolder name became popular. they should have called it Black canyon Dam!!

Bolder ≠ Boulder

useful link.

Cement trucks are used to perform two functions at once. Mix the concrete and deliver. And that's doing both at the same time. What you need to do is have the dry ingredients loaded in the truck, have it driven to the site, add the water, and then have it mixed on site.

Not being of the cementatious engineering persuasion, how long does it take to mix 12 yards of concrete after adding water?

The largest mixer truck will hold 12 yards. It would take 20 to 30 minutes depending on the type of mix and the humidity and ambient temperature.

I agree about mixing on site, i suggested a portable batch plant, though im unsure if there would be one available in his part of the world, i wouldent think they would be so uncommon.

I see them all the time here in Michigan, I think it's cheaper to batch on site if you have many pours at the same site.

It is, we have used them in iowa texas utah........ but i don't think he is in the states, but yes, they are quite common here

It actually depends on the batch mixer, transport to the site of the mixer as opposed to buying from a concrete company that will transport the mixed product to the site.

Batch plants to be cost/time effective must used in multiple units. the time spent loading and mixing is lost and you get a weak joint where you start again. Batch plants if not used in multiple units are just too slow. Been there done that!

Having water added by the Ready-mix truck driver will surely end up with a over or under hydrolized batch of concrete, which is detrimental to it's compressive and tensile strengths. Even front loader trucks have a slump meter, and that is not all precise in estimating the exact required amount water.....it's a only a 'guessimate'.

You need to have the water added at the batch plant for obtaining the PRECISE amount of water to obtain the proper Water-To-Cement Ratio (W/C) and slump pursuant to the Concrete Technical Specifications if any.

Capt Moosie,

On most projects an inspector is present on site to do an actual slump test as well as take a sample that will be destructivly tested from each and every truck off loaded on site. Temperature is also taken and can be a reason to reject the truck load if the reaction is started.

I have off loaded many thousands of cubic yards on construction sites. One particular scheme had to have minimal water mixed so it would stand to a 0 slump. Concrete can and will fully set to maximum bearing without any water at all. There are plenty of engineering schemes that use minimal water in the scheme. Pressure injected footings are just one of these.

Yes Bob, I am fully aware that an independent testing agency can have testing personnel on-site to perform a series of tests on concrete: Slump test, air-entrainment test (if necessary), concrete and ambient air temperature readings, and to make concrete cylinders. That is, if you're lucky to get the Owner of the project to agree to those tests and associated costs.

On most public works projects you'll find the concrete testing technician (not necessary an "Inspector"....there is a distinct difference between the two.). On privately-owned construction projects, there may not be any concrete testing at all, which IMO is quite foolish and gives the Owner little or no legal recourse to go after the Contractor and concrete supplier if the concrete is not meeting the project Technical Specifications. I've seen it go both ways.

I'm not exactly a fan of Zero slump concrete, unless there are moderate or high plasticizers present in the batched mix, and even then you have to be extremely careful how the batch is mixed, off-loaded, and placed (not poured, which is a misnomer). Zero slump can actually lead to a whole host of concrete compressive, tensile, and rupture strength problems.

You could always measure the water precisely at the plant - put into a drum, then add & mix at required time on route.

Are you advocating that the ready-mix truck driver add water enroute? No way would I allow that to happen on any of my projects......that practice is ripe for concrete strength degradation.

If any water is necessary to bring the concrete within the specified slump range, it should only be so ordered by the Resident Engineer (who works under the direct supervision of the EOR) at the project site, only after careful consideration in a telecom conversation and approval by the Engineer of Record (EOR), who ultimately bears full responsibility for his/her actions that said deviations applied in the field to the resulting concrete falls within the specified tolerances.

You will find such operational control in most concrete technical specifications, such as MasterSpec, USACE specs, and a whole bunch of other specifications...

I'm enjoying your hydration ping pong match but I thought this was a nitrogen discussion

Yuppers, we've sort of got sidetracked didn't we? LOL