×
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

Concrete Steel Mould

Concrete Steel Mould

Concrete Steel Mould

(OP)
I'm looking for some kind of paint or sealant to spray or apply onto the steel mould, this would need to be very durable as in the manufacturing process the steel gets vibrated. At the moment the concrete is sticking to the surface, which is why I need to apply some sort of durable finish onto the steel surface.

Any help would be greatly appreciated.

RE: Concrete Steel Mould

What are you casting? Is it big or small?

After casting is your mould fully demountable i.e are the sides removed so your cast concrete is just on the flat base?

Is the concrete getting stuck in general or only at corners?

Have you tried different release agents (formwork oils)?

RE: Concrete Steel Mould

Usually, before each use, the formwork is cleaned and from oil is applied to keep the forms in top performance. This helps the product stripping quite managable as well.

RE: Concrete Steel Mould

Wet cast concrete or zero slump?

Stripped/extruded from the form or forms disassembled?

Surfacing and hardening of the mold surfaces is frequently used in conjuction with admixtures for off site applications.

You can also look into changing the vibration frequency and/or amplitude.

Dick

RE: Concrete Steel Mould

(OP)
The surface area of what we are casting is 6M long by 2.5M High by 80mm thick.

The mould is fully demountable, it opens out like a door.

The concrete is getting stuck generally, not just at the corners.

We have tried various different formwork oils.

Sometimes it releases off the metal form but the majority of the time it sticks in patches

It is wet cast concrete, the forms are disassembled and the concrete wall tie panel is lifted out.

We have changed the vibration to the minimum we would need to apply but the promlem remains.

RE: Concrete Steel Mould

I've had problems with steel forms before but never as you describe.

I guess (and I hope the other guys have a better idea than my guess) that the problem is either that the face of the form has been damaged by aggressive cleaning - wire brush or grinder - or that the concrete is cleaning off the form oil as you place the concrete.

I have never seen a surfacing for steel forms, would have thought it is more likely that the coating would get removed.

As an experiment I would try engine oil mixed with a bit of diesel (to make it more fluid) to see if it could be more effective than a release agent. If it works I would try buffing the steel face with the same mixture and then try to get an oil based formwork oil (didn't they used to be made from fish oil?)

RE: Concrete Steel Mould

There are numerous debonding agents available.

In tilt-up concrete they use a debonding agent to prevent bonding between old and new concrete. I suggest you google that topic.

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