Q.: A steel tank is to be built in a remote area to hold asphalt. A stable insulating base is needed and it is proposed to make this base of perlite concrete of 190 psi compressive strength. Can ocean water be used in the perlite concrete mix? The only alternatives would be to truck the water in or drill a well.

A.: If the bottom of the steel tank can be protected adequately against corrosion from chlorides and other salts in the concrete mix, the ocean water should be satisfactory. The water may have a small adverse effect on strength and the time of set, but if the mix is designed with this in mind it should be possible to use ocean water.