Severe exposure to unknown substances
Severe exposure to unknown substances
(OP)
Got a bit of a fun one here - it's a single-story concrete moment frame, supported on caissons, with about half of the building extending out over the Anacostia river here in DC - so half of the building columns are going to be exposed to running water from one of the most polluted waterways in the nation. Basically, there could be pretty much ANYTHING in this water. The other half of the project is sitting on a recovered brownfield, and we're not sure what's buried there either.
My main concern is the concrete itself - we're planning on using 40-50% GGBS both to help resist sulfide attack and for the LEED points (project is shooting for platinum certification). I'm figuring we'll need a Class V cement, and gut is saying a significant level of air entrainment for crack control since freeze/thaw is a definite consideration, although I'm concerned about the pockets that would create.
I'm also quite concerned about cover and jointing - I wouldn't consider using less than the 3" cover from ACI, but in this case I'm wondering if even that's too low - and can't seem to find a specific reference for exposure to indeterminate deleterous substances. Similar issue with the cold joint between caisson and column - definitely don't want it underwater, but don't particularly want it right below my slab either.
Anyone have any specific experience or recommendations for research on this type of condition?
My main concern is the concrete itself - we're planning on using 40-50% GGBS both to help resist sulfide attack and for the LEED points (project is shooting for platinum certification). I'm figuring we'll need a Class V cement, and gut is saying a significant level of air entrainment for crack control since freeze/thaw is a definite consideration, although I'm concerned about the pockets that would create.
I'm also quite concerned about cover and jointing - I wouldn't consider using less than the 3" cover from ACI, but in this case I'm wondering if even that's too low - and can't seem to find a specific reference for exposure to indeterminate deleterous substances. Similar issue with the cold joint between caisson and column - definitely don't want it underwater, but don't particularly want it right below my slab either.
Anyone have any specific experience or recommendations for research on this type of condition?





RE: Severe exposure to unknown substances
Any way you can get a membrane on the outside of the concrete?
Just throwing a couple of ideas at you, I dont have any answers, sorry.
RE: Severe exposure to unknown substances
RE: Severe exposure to unknown substances
http://www.cement.org
RE: Severe exposure to unknown substances
RE: Severe exposure to unknown substances
RE: Severe exposure to unknown substances
RE: Severe exposure to unknown substances
your post just reminded me of when i worked at the DCWASA wastewater treatment plant serving DC, North VA, and South MD on that river in Anacostia. ~400 MGD typical and ~700MGD after storms i think it was. The effluent from that plant is the best thing going for that nasty river.