Precast Water Tanks

[JKW05]

We are considering the use of a precast, post-tensioned water tank in a sewage treatment plant. The tank is approximately 25 feet high and 60 ft diameter. I know many tanks of this type are being used, but my main concern is the number of joints that are necessitated by the precasting operation (approximately 8 feet o.c.). Does anyone have any opinions or insight on what might be expected in 25, 30, 35 years? Any information about tanks of this type that are being repaired or refurbished? Failures? What caused the failures?

 

[JedClampett]

There are several types of prestressed tanks. Each region has a manufacturer that wins practically all the projects. In the SE it's Crom, in the SW it's DYK, Texas Natgun, etc. Each one has a different technique, so check with your local manufacturer on their method. The joint spacing is specific to the manufacturer.
As far as problems, they're few and far between. I had to do remediation on a tank where some drunk yahoos had used it for target practice and damaged some strands. I've had to replace the dome roof prestressing for a 40+ year old tank. But these things are pretty reliable.