Watertight Diaphragm Wall Joint
Watertight Diaphragm Wall Joint
(OP)
I am researching the detailing of a joint between a diaphragm wall and the base slab. The base slab is at -15m, 1,200mm thick and will be cast against the diaphragm walls. My main concern is forming a watertight joint.
The first thought I have is that if we place bend out starter bars in the diaphragm wall when bending the bars out local crushing of the concrete and micro cracks may be formed causing a water path.So maybe couplers are required.
Next is the possible leakage at the joint between diaphragm wall panels where there may be a waterpath from under the base slab and around the panel joint on the inside face of the wall.
Can anyone point me towards any details on the internet. I have already ordered a book which promises me details, but the more info the better....
The first thought I have is that if we place bend out starter bars in the diaphragm wall when bending the bars out local crushing of the concrete and micro cracks may be formed causing a water path.So maybe couplers are required.
Next is the possible leakage at the joint between diaphragm wall panels where there may be a waterpath from under the base slab and around the panel joint on the inside face of the wall.
Can anyone point me towards any details on the internet. I have already ordered a book which promises me details, but the more info the better....






RE: Watertight Diaphragm Wall Joint
Try here: Hydrotite
RE: Watertight Diaphragm Wall Joint
RE: Watertight Diaphragm Wall Joint
thanks for your input. I agree that 100% watertight may be a high expectation - but a good starting point.
We are considering grouting the diaphragm panel joints on the inside face above and below the base slab.
The main leak path (assuming that the diaphragm walls themselves don't leak - but we will treat that as a separate problem) would then be from the underside of the slab, through the wall/slab construction joint. I have sent a message to the supplier suggested by JAE, but yet to see if they have a prescence in S.E. Asis.
What about casting in grout tubes so that in case of a leak grout can be pumped in. I have used such tubes for shaft grouting bored piles, but I don't know how the system would work in a construction joint.
RE: Watertight Diaphragm Wall Joint
Dik
RE: Watertight Diaphragm Wall Joint
Volclay RX bentonite strips sounds like a bentonite based product similar to Hydrotite hydrophilic waterstop as suggested by JAE.
But what is blueskin? I don't like the idea of an "angle" as steel is increasing in price every day. But if the cost is required.....!
RE: Watertight Diaphragm Wall Joint
It's not intended for this application, but it works well... The blueskin I normally use is for commercial/industrial applications...
Dik
RE: Watertight Diaphragm Wall Joint
about two years ago in the NW of the US this system was runnng about $2/lf, not bad for a fail safe.
Basically you do the best you can with all other measures and then you have this system installed to get problem areas fixed later if you do, belts and suspenders.
RE: Watertight Diaphragm Wall Joint
thanks. I also followed JAE's link which took me to a company called Greenstreak. Greenstreak don't distribute outside USA so have recommended me to a FUKO contact for grout tube (in Germany) and Itochu Specialty Chemicals, Shamburg, IL 60173 for the hydrophilic waterstop - but expect I can easily get a local distributor for this kind of product.
I'm still looking for standard construction details for a typical joint (e.g location of waterstop top or bottom of base slab)
RE: Watertight Diaphragm Wall Joint
RE: Watertight Diaphragm Wall Joint
I have some out-of-print recommendations from the Portland Cement Association on constructing "watertight" concrete on this page of my website
http://www.slideruleera.net/PCA-Page.html
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