×
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

Precast Stripping Test

Precast Stripping Test

Precast Stripping Test

(OP)
Friends,

In an effor to reduce our rework dollars for the upcoming business year we are looking at some of the more costly problems that we have with our process.  One problem is stripping the product early or when it is to "green".  

I have been asked to find out if there is a test that can be preformed on a product when there is a question if it will break during stripping.  Bear in mind that the products that I am talking about are 4 diameter precast manhole pieces, and that making cylinders for each piece or for each batch of concrete is not a cost effective test.  ie: We would spend more testing than we would lose by not doing anything.  

Thanks for any help that you can give.  

LNT

RE: Precast Stripping Test

Would breakage be due to stripping the forms, or concrete not strong enough to support it's own dead weight unsupported?

I'd mix up a batch of minimally-acceptable concrete, do a bunch of test cylinders, find out how long it takes to reach the desired minimum strength, and add a factor of safety.

------------------------------------------
      "Come to think of it, there are already a million monkeys typing on a million typewriters, and the Usenet is NOTHING like Shakespeare.

        Blair Houghton

RE: Precast Stripping Test

Some ideas.

Use a Schmidt hammer test, although not very reliable in a absolute sense it could help.

Change the mix, increase the cement content, use an additive to reduce the water, add polypropylene fibres, increase curing temperature, use High Early Strength cement. Although all cost money, it may be less that you are wasting at the moment.

StephenA

RE: Precast Stripping Test

4 foot diameter manhole sections? Are you curing with steam? Wet cast or dry cast? How long have you been waiting?

RE: Precast Stripping Test

How about a little "low-tech" in-house experimentation? The biggest factors are probably "time" and "temperature". Keep notes on the environmental conditions and try stripping at  different times - your company's employees are in the best position to determine what results are acceptable and what are not. After a very few well choosen trials you will probably have your answer.

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