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RE: Circular Concrete Tanks without Prestressing

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Harold, thanks for your input.  You mentioned the following products:

> There are adhered expansion joints like the Jeanie and Will 
> Seal...

I have a relatively old catalog for Will-Seal by Illbruck, Inc.  It appears
to be intended mainly for above grade sealing and the specs say to test it
only for 2-inches of water.  Has it since been tested for higher heads under
full hydrostatic head? 

We have used the Jeene joint sealing system on wider joints, but the
smallest joint it is made for is 3/4-inch.  I am currently trying to seal
1/2-inch joints. 

> Another solution that would seal smaller cracks is injecting 
> Sikafix.  This product expands upon contact with water and remains 
> resilient.  

Sikafix is a polyurethane grout, which is similar to the chemical grout
injected into such joint sealing systems as the "Injecto Tube" by DeNeef.
This system is primarily intended to be used in construction joints - a
permeable tube is cast into the construction joint and chemical grout is
injected into the joint after it has been constructed, filling the tube and
any voids with water reactive grout.  I have used this system in expansion
joints before - sometimes with success but a recent project has run into
leakage problems with this system in an existing expansion joint.  I'm not
sure if it is a "system failure" or an installation problem.  So far this is
the best solution I have found, but I am still searching for other
solutions.

I am currently looking into a similar detail using Greenstreak Hydrotite
expansive "rope".  A circular rope of water reactive material could be
precompressed like a backer rod and inserted into the joint.  Again, the
material is primarily intended for construction joints, but I've heard that
it may have been used in an expansion joint at one project - I am still
trying to get more data on that.  

These expansive grouts also have differing properties.  The injection grout
must be wetted at installation and expands to form a closed cell
polyurethane foam which remains permanently expanded.  The expansive rope
expands and contracts with wetting and drying cycles and takes some time to
react (i.e., could leak initially until becomes fully reacted).  Currently I
prefer the injection grout which is intended to expand and form a
compression seal as well as have bonding and elongation capabilities.