We have a project where a reinforced concrete manure
holding tank with sloped embankments was installed with improper waterstops.
This tank was intended to be installed per NRCS standards where the concrete
provides primary containment i.e. no liner. I’m looking for ideas on how
to fix. Current considerations area as follow:
1 - Place a geomembrane on top of the existing faulty
concrete then apply a protective layer, maybe 4”, of concrete. Install control
joints without water stop. Probably thicken concrete at base of side slope for
some distance. Anyone see a problem with this approach?
2 – Repair using a detail similar to that shown in ACI
350.2R-6 Fig 3.1 with a 12” neoprene or sim. continuous patch over the
existing improper waterstops. However, this holding tank gets cleaned out with
end loaders at end of year so the patch would need to have concrete cover and
I think that would get ripped off and or the feathered end would not hold.
Thoughts or ideas?
3 – Place a new slab on top of existing slab to meet
required spec. with all reinforcing and properly installed waterstops. I am
worried about getting excessive random cracking due to placing on top of 2-yr
old concrete – would placing a thin layer of sand or sand and a vapor retarder
help? Of course if they installed the waterstops wrong the first time… this
may not be the best choice…
4- Pressurize under slab to find leaks and then try to
inject with expanding sealant in specific areas to seal. This is probably the
low cost method but not sure how well this could be done. Anyone have
experience trying this?
Any thoughts, ideas or related experiences would be
Puccio P.E., S.E.