HOW CORROSIVE IS SEAWATER TO CEMENT COATINGS?

[soflapoolboy]

WE INSTALL POOL PLASTER MOSTLY IN REGULAR SWIMMING POOLS. A CUSTOMER OF OURS IS BUILDING A SALTWATER SWIM POOL THAT WILL BE FILLED WITH OCEAN WATER LOCATED IN MIAMI, FL. WE ARE AWARE OF AND PLAN TO USE A SILICA-FUME TYPE POZZOLON ADDITIVE THAT WILL DENSIFY OUR MATERIAL AND MAKE IT LESS SUSCEPTABLE TO SALT ATTACK. DOES ANYONE HAVE DATA ON THE CORROSIVE RATE OF SALTWATER ON CEMENT? ANY INSIGHTS WOULD BE GREATLY APPRECIATED!
THANK YOU,
JASON

 

[mshimko]

You may want to post this on the Civil Engineering forum (although double posting is discouraged, I think you'll have more responses there).

I'm NOT an expert in this area, but from my limited knowledge of concrete I believe the main problem isn't "corrosion of the concrete", but corrosion of any rebar, where the corrosion byproducts are more voluminous than the steel causing stress and eventually cracking of the concrete.

 

[boteng]

You may want to try contacting a masonry supplier. There are coatings for cement that are made to resist the effects of salt. They make it for covering driveways and walkways in the north because of the effects of people salting to get rid of ice. It should work for a pool though I'm not sure of leaching over time. One company I have dealt with is Silpro. They sell in New England. I'm not sure if they are around where you are, but it might be worth contacting them.

 

[metengr]

soflapoolboy;
Perform a Google search on the topic of chemical (chloride and sulphate) attack of Portland cement. There are plenty of hits to evaluate.