Sea water and cyanide (acid) resistant concrete mix design 1

[tvar]

I have been asked to specify a concrete mix which will be in contact with wash down water which will be sea water, diluted cyanide and acids. At this point sugestions have been to use higher strength concrete 40 Mpa, use 75 mm cover to the rebar and add silica fume or a pore blocking and/or water repellant admixture. An additional constraint is that it will be placed in a desert climate even though the pours will probably be at night. Does anyone have any comment or additional infomation? Thanks

 

[MiketheEngineer]

How about coating the concrete with something that is resistant to this nasty soup??

 

[tvar]

They are going to use a barrier coating in acid wash and hydrochloric acid storage but it wouldn't be cost effective in the rest of the plant areas which aren't as corrosive. Thanks for the response

 

[Ron]

tvar...acids don't play nicely with concrete, since it is primarily alkaline. The soup you described will be aggressive to the concrete and will require a coating that will resist both abrasion and chemical soup...suggest epoxy coating.

 

[masrizal]

I had very bad experience with our chemical waste pit which was suffered damage very soon after in contact with hydrochloric acid. The concrete pit was made with cover of 10cm, high strength concrete of 40Mpa, and the mix was with 10% fly ash. It did not work at all against the acid attack.

The epoxy coating might be the best.

There is rapid test to check your mix design whether it resist the acid or not.

 

[tvar]

Thanks masrizal, The end of your post said there is a rapid test to check if the mix is acid resistatnt but it didn't show in the post. Can you post it. Thanks again

 

[3feethighandrising]

Lumnite MG is a cement highly resistant to chemicals and acids. Haven't used the product myself, but have been researching it. There is good info on their website.

3'

 

[rconner]

Have any feel for pH that will be involved? (As far as as seawater is concerned, maybe very good quality mix and application, with low but adequate for cure applied w/c ratio, low applied voids/permeability etc. may at least help regardless of specific cement type chosen)