×
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

loading from concrete as backfill to wall

loading from concrete as backfill to wall

loading from concrete as backfill to wall

(OP)
I have a concrete wall that behind will be backfilled with mass concrete. The concrete will be liquid state (or thereabouts) when poured so what loading criteria should be used? treat as hydrostaic with unit weight of 24 kn/m2? probably conservative?  

RE: loading from concrete as backfill to wall

I'd say absolutely hydrostatic. I'm sure you mean m^3.

RE: loading from concrete as backfill to wall

either design your wall for full hydrostatic pressure, or pour the slurry backfill in lifts and allow it to partially set before pouring the next lift.  You don't need to allow full cure, just enough time between lifts for the concrete to stiffen so that it no longer behaves as a liquid.   

RE: loading from concrete as backfill to wall

(OP)
yes sorry, m3.  

RE: loading from concrete as backfill to wall

See ACI 347-04, there are formulas provided for given concrete properties. I see this as similar to pressure against formwork which is what ACI 347 addresses. I would expect some locked in stresses in your existing wall & ftg after the newly placed concrete hardens behind it.   

RE: loading from concrete as backfill to wall

look up the formwork code, your retaining wall will be acting as permanent formwork.

RE: loading from concrete as backfill to wall

I've had two instances of contractor's filling cavities between blockwork leaves with liquid concrete without phasing it in lifts.

The pressures from wet concrete can be significantly higher than those from the ground. Insist that the work is done in lifts, not all at once.

Use a drier concrete mix if you can.

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