Crack in epoxy-urethane polymer sealant 3

[Q5CM]

Hi Guys,
I need help regarding a situation I have on site as below;
I ( client) am using a epoxy-urethane sealant in the concrete movement joint between two floor slabs, do to wrong application two defects appeared 1) a crack in the sealant appeared( in the middle) and 2) the sealant seperated from one side of the concrete.
the contractor wants to repair in the the following way,
1) by injecting more material into the cracked material

2) by repairing the concrete edge then reapplying the filler.

i am worried that solution 1) is not durable and solution 2) will cause the concrete repair to breakoff

 

[MintJulep]

This is the same contractor that did it wrong in the first place?

Dig all the old sealant out. Clean and prepare the edges properly this time. Then fill the joint with new sealant.

 

[dik]

I assume the joint is moving.

How wide is the joint and what is the thickness of the sealer. The joint should be twice as wide as the sealer thickness as a rough rule of thumb.

Use an ethafoam backing rod and bond breaker if necessary.

dik

 

[Tmoose]

Are either of these slabs more than 20 feet long/wide? How long had the concrete cured before the sealant was applied?
If the slabs are moving vertically due to improper soil prep, or moving a lot due to some other design deficiency then it may be asking too much of the sealant.

Yeah, backer rod is probably necessary to create the right profile. Lots of glue area is needed at the edges for the caulk to grip the concrete strongly, and the curved thin section in the middle is stretchy without stress concentration.

section

http://www.fhwa.dot.gov/pavement/pccp/pubs/06005/images/06005f1.gif

Here's a pretty good description, and the source of the image.

http://www.fhwa.dot.gov/pavement/pccp/pubs/06005/

 

[Ron]

You are using the wrong type of sealant/joint filler. Control joints in concrete will move, mostly by shrinkage. Remove all that is there.

At best, you need a semi-rigid epoxy (W.R. Meadows ReziWeld Flex) or if you anticipate continued, significant joint movement, a flexible sealant such as Meadows Pourthane NS, Sonneborn NP-1, Vulkem.

Make sure a proper sealant profile is achieved using a backer rod under the sealant.

 

[MiketheEngineer]

Or are the slabs still moving??