Efflorescence Build-up
Efflorescence Build-up
(OP)
Attached is a picture of what I believe is efflorescence build up on the exterior wall of a tunnel. It builds up to almost a 2" thickness (iv never saw eff. build up like this, hints the "I believe" clause). I believe it is a concern based on what I have read to this point as it can be harmful to the longevity of the concrete based on the water coming through the wall and degrading the concrete of minerals.
Would you agree this is a viable concern?
My first thought on fixing is a spray on water barrier as some claim to be able to be applied on the inside face of a wall and keep water from "flowing" through as I believe is the issue here.
Thanks in advance for any help.
Would you agree this is a viable concern?
My first thought on fixing is a spray on water barrier as some claim to be able to be applied on the inside face of a wall and keep water from "flowing" through as I believe is the issue here.
Thanks in advance for any help.






RE: Efflorescence Build-up
Dik
RE: Efflorescence Build-up
You can try patching it, but pushing water back through a joint is not easily done. I think you have to chase out that joint as deep as you can, then use a Xypex type of repair material in the joint followed by a surface coating in the local area.
RE: Efflorescence Build-up
Dik
RE: Efflorescence Build-up
A "spray on water barrier" on the inside won't help.
RE: Efflorescence Build-up
Dik
RE: Efflorescence Build-up
-I will have to research the design drawings to see if there was a water membrane to be on the outside of the wall. I would hope so, but my gut feeling is that there was not or it has failing hints what we are seeing. It would be nearly impossible to treatment on the outside of the wall at this point.
-I did not collect a sample, could possible make an additional site visit to collect and see if that will help me more.
-I believe this is an active crack, so seems like it may limit my solutions.
-There is a roadway over the top (approx. 15' above) of this so not sure if deicing salt would play a role in this seeping through the soil and into the tunnel crack.
RE: Efflorescence Build-up
Looks like it could be a good candidate for crack injection.
RE: Efflorescence Build-up
Dik
RE: Efflorescence Build-up
Yes, it depletes minerals in the concrete, most notably calcium, the largest elemental component of portland cement.
Your issue appears to be localized to a crack or joint. It is caused by recurring moisture migration through the concrete.
You do need to test the residue. It will help solve the problem.