Gravity flow of grout in new PVC vs existing steel pipe
Gravity flow of grout in new PVC vs existing steel pipe
(OP)
Hi all,
I've been banging my head against the wall with this one and can't seem to get it.
Background: I am a mechanical engineer working for a federal agency reviewing a test report regarding grout formulation provided to us by a contractor. The grout will be for waste stabilization of underground tanks and pipes.
Set-up: See attachment for test set-up rig. Pipes are made of Sch 40 PVC. Three of the six pipes are capped and three are not. Using a particular formulation of grout (composition and material properties shown in attachment), the result of the test is that the grout completely filled the vented 4" and 6" lines and the capped 6" line, the grout traveled 18' in the vented 2" line, 5' in the capped 4" line and 1' in the capped 2" line.
Problem: Existing conditions are not brand new, smooth PVC pipe, but 50 year old steel pipe that has had highly radioactive and highly toxic water and goo flow through them on an occasional basis. I would like to focus particularly on the vented 2" pipe and estimate how far the grout would flow if the pipe was more like real world conditions.
Any thoughts or ideas about how to do this would be much appreciated by Uncle Sam (and me). I hope I did leave out any relevant information. Thanks!
I've been banging my head against the wall with this one and can't seem to get it.
Background: I am a mechanical engineer working for a federal agency reviewing a test report regarding grout formulation provided to us by a contractor. The grout will be for waste stabilization of underground tanks and pipes.
Set-up: See attachment for test set-up rig. Pipes are made of Sch 40 PVC. Three of the six pipes are capped and three are not. Using a particular formulation of grout (composition and material properties shown in attachment), the result of the test is that the grout completely filled the vented 4" and 6" lines and the capped 6" line, the grout traveled 18' in the vented 2" line, 5' in the capped 4" line and 1' in the capped 2" line.
Problem: Existing conditions are not brand new, smooth PVC pipe, but 50 year old steel pipe that has had highly radioactive and highly toxic water and goo flow through them on an occasional basis. I would like to focus particularly on the vented 2" pipe and estimate how far the grout would flow if the pipe was more like real world conditions.
Any thoughts or ideas about how to do this would be much appreciated by Uncle Sam (and me). I hope I did leave out any relevant information. Thanks!





RE: Gravity flow of grout in new PVC vs existing steel pipe
In general, since this isn't a real pipe flow problem anyway, I would recommend that, if you need better than what you're seeing now, that you concentrate on a more effective method of grout placement, such as actually pumping it in under pressure, inserting a vent tube in the unvented pipes and withdrawing it as the pipe fills, or perhaps introducing a smaller amount of grout and vibrating it until it reaches the bottom of the pipe, then introducing another small batch on top and vibrating that down, rather than depending on gravity flow on a 3% sloped pipe. Those are much more standard reliable methods for placing cement grout and concrete that minimize the possibility of the development of honeycombs and voids.
RE: Gravity flow of grout in new PVC vs existing steel pipe
RE: Gravity flow of grout in new PVC vs existing steel pipe
RE: Gravity flow of grout in new PVC vs existing steel pipe
1gibson, it would be nice to re-run the test with scrap pipe, but this money has already been spent and contractual obligation has been met. So, unfortunately its not a possibility.
RE: Gravity flow of grout in new PVC vs existing steel pipe