×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Min temp for concrete

Min temp for concrete

Min temp for concrete

(OP)
Hi,

Is there any document or code which talks about the minimum temperature resisted by the concrete of different grades. We are using this concretre (cube strength 40n/mm2) for cryogenic spillage and to design the insulation for the same i need minimum temp which can be sustained by this concrete.

Thanks in advance.

RE: Min temp for concrete

I didnt know there was a minimum temparature if it is cured already.  I am watching this post.

http://www.swijetty.com
Sea Water Intake and Jetty Construction

RE: Min temp for concrete

Years ago, in Southern California, I worked in the aerospace program. Our company used a great deal of cryogenic materials (mainly hydrogen, LOX and even played with FLOX) in addition to liquid hydrogen and petroleum compounds. Much of the structures were stainless and all our gratings and supports were stainless because they also supported the piping. I appreciate your situation.

All finished ground cover was concrete since asphalt was too good of a fuel. We were concerned about the concrete life since some splls occured around the tanks. There was no corporate or government money for a quick answer, so we conducted some non-scientific testing/observations - impact, chipping after repeated exposure. We did not have any numbers.

It appeared that higher strength air entrained concrete held up better, probably due to the entrained air voids, just as it does for freeze-thaw resistance.

Based on some other things I have seen in some Russian durability testing, I would suspect that lightweight concrete made with quality lightweight aggregate (not natural pumice, scoria, etc.) could offer some advantages because of the void structure. Manufactured rotary kiln expanded shale or clay (uncrushed in all sizes if possible) would be a good starting point. This also offers additional insulation compared to convential heavyweight concrete.

The lightweight aggregate producers may have some information on the subject. Google Gravelite, Arkalite and Livlite for possible information sources. The guru of the industry was a brilliant man, Thomas (Tom) Holm, who authored many very technical ASTM, ACI, etc. papers on the structural and other uses of lightweight aggregate. He has retired, but some of his information should be available.

I hope this helps you on your quest in this narrow application of concrete.

Dick

RE: Min temp for concrete

concrete masonry is on the money with pointing you towards lightweight aggregate, although there are other options.

What duration and frequency of exposure are you looking at?  You can approach things differently for spills or storage.

RE: Min temp for concrete

(OP)
hi,
actually this is a LNG inpoundung basin. So if there is any leak from the valves or from the tank itself, it will routed to this basin. To insulate it from the -160deg LNG we asked the foamglass supplier to gives us the required thickness of foamglass but in his response he is asking about the minimum temp which this concrete can resist. Then only he would be able to tell us the thickness of the insulation required.
Any thoughts on this ?

RE: Min temp for concrete

Cryogenic temperatures aren't a huge drama, assuming sensible mix designs and reinforcing choice.  The problem is with differential temperatures and rate of temperature drop.  A rapidly cooled surface and comparatively warm slab interior (e.g. a spill) will behave as you'd expect, cracking and spalling progressively through the slab.  You can see why air-entrained, higher-strength concrete helps.

More information tends to overlap with how I pay the bills.

RE: Min temp for concrete

(OP)
Thanks all of you for the info. I think i would still go for foamglass insulation of 150 thk as i would keep concrete temp above -10deg for 2.5hrs as specified by HSE.

RE: Min temp for concrete

If you want to check a little further in to the properties of concrete at cryogenic temperatures just enter "cryogenic" in search box.

http://www.concrete.org/SEARCH/metasearch.aspx

I don't know about Foamglas as an insulating membrane for LNG as I have it that the low temperature limit is -100F.

RE: Min temp for concrete

(OP)
Thanks unclesyd  for this link. This in fact seems to be quite useful.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources