Cutting doors in existing concrete tiltwall panels

[john89]

I have seen many ways of doing this. If existing drawings are available that indicate existing reinforcing, what design parameters should I be looking for? Obviously the new door cut into the wall will not have the additional rebard around the opening that is typically detailed for a new wall with an opening cast in.

One method that I have used is to frame the opening with a bent plate channel mitered at the corners and welded. This ensures that cracking does not occur at the corners but may be overkill for a 3'-0" door opening.

Anyone else have any good methods of reinforcing? This is a load bearing wall spanning between drilled piers.

 

[SperlingPE]

Is it possible to add steel strap to inside and outside face of the panel?

 

[cap4000]

Are you sure your tilt up panel just has rebar in it or is it a pre-stressed panel design??

 

[john89]

tilt panel only has conventional reinforcement

 

[dik]

Can you secure a small channel to the back of the panel? How close is the topof the opening to the top of the panel and how much material do you have on either side of the opening?

Is it possible to have the one edge of the opening at the edge of the panel?

Dik

 

[miecz]

If this is a load bearing panel spanning over drilled piers, doesn't a door take out the tension side of the panel?

 

[csd72]

I have cut holes into panels without any additional work before.

There are no edge bars, but the main reason they are in is for casting and early shrinkage.

Unless you have very high thermal expansion or frost in the area, I would not be too concerned that there are not any edge bars.

I have seen a number of renovations done like this in Australia with no problems 10 years on!

You need to check the strength by a rational analysis though, and you cant rely on this as a shear wall.

 

[soukup73]

You may want to investigate using carbon FRP composite strips? - very unobtrusive and effective in a bending sense.