Fill-in Existing Opening

[broekie]

I am working on a pump station project where the pumps are being replaced and as a result there are some minor structural modifications being done.

One of the modifications that we are doing is "filling in" an existing 16" diamter hole in a 12" thick concrete wall. There used to be an outlet pipe going through this opening, but the pipe is no longer required so the owner would like to fill in the hole.

Any suggestions out there as to the best way to do this? I would like to drill and epoxy some bars into the existing concrete so I was thinking I would actually have the contractor chip out a little more concrete to make that job a little easier.

I have no idea how the contractor would get concrete to fill in this hole, though. The way I see it is that he has to form up both sides of the opening, since this is a vertical wall. But then since the hole is in the middle of the wall, how does he get the concrete to fill in the hole? Can non-shrink grout be used?

Any help would be appreciated. I don't have a lot of experience with stuff like this in the field. Thanks.

 

[SlideRuleEra]

broekie - Unless the plug is going to subjected to a force (perhaps air or water pressure) doubt if you need to put in the rebar or use epoxy. Just "rough-up" the surface, clean it, keep the surface damp (say with wet rags) overnight, and place the concrete the next morning. Bring the forms up close to the top of the hole so that as much concrete as practical can be put in with a small shovel. Remove the forms as soon as the concrete will remain in place - probably the same day it is placed. A concrete finisher can then easily patch the remaining top of the hole at that time. Keep the plug damp (the wet rags, again) for a week or so for curing. For a hole that size concrete should be fine, no need for non-shrink grout.

http://www.SlideRuleEra.net

 

[miecz]

If you have an existing flanged pipe, leave it there and cap it off with a blind flange.

If you have removed a sleeve, and you have water pressure to deal with, drill and grout 4#4s radially, and install an expanding (Rx) waterstop.

I would not remove any concrete from the inside of the hole, as this will reduce the cover to the existing reinforcing, which was probably criss-crossed around the opening.

 

[broekie]

Thanks for the advice, both of you. I'll take both answers under consideration.

 

[jike]

If this is below grade, I would use hydraulic cement.