Waterproofing at Form Ties in Concrete Walls 3

[abusementpark]

How is waterproofing normally achieved at form ties in concrete walls? It looks like the ties are typically left to remain in place and you can specify a neoprene washer in the middle, is that right?

 

[SlideRuleEra]

Yes, use a neoprene or PVC washer. Get snap ties that break off at least 1" deep then plug the holes. Use pressure injected epoxy to plug the holes for best results.

http://www.SlideRuleEra.net

 

[Ingenuity]

Fiberglass form ties are also an option, with neoprene washers. Cut-off at face of finished concrete and no plug patching, nor corrosion.

 

[abusementpark]

Yes, use a neoprene or PVC washer. Get snap ties that break off at least 1" deep then plug the holes. Use pressure injected epoxy to plug the holes for best results.

So typically the majority of the form tie is left to stay-in-place in the wall and only the ends are removed?

 

[SlideRuleEra]

abusementpark - Yes:

There are variations on the type of ties, like Ingenuity shows. As may be expected, all have pros and cons (ease of use, cost, speed of installation, load capability, etc.) To my knowledge, all form ties have expendable parts that remain embedded in the finished concrete.

http://www.SlideRuleEra.net

 

[Ceinostuv]

Some of the formwork manufacturers also have proprietary waterstop solutions. PERI and Doka have some, off the top of my head, and I'm sure the other major formwork systems would have some as well.

Edit: SlideRuleEra, there are some reusable ties that don't have sacrificial parts. DYWIDAG taper ties for example.

Judgement-In-Training

 

[SlideRuleEra]

Thanks, Ceinostuv, it's been a long time (1980) since I left the bridge construction business.

http://www.SlideRuleEra.net

 

[DTGT2002]

There are also tapered ties used in heavier form construction that leave a smooth, but tapered hole that may be patched back in a number of ways, that do not leave a remnant of the tie in the work.


I would hazard to say that in many cases, typical construction methods for structures would expect performance beyond that of the concrete wall in itself, so a waterproofing membrane would be expected on the entire wall.


Water retaining structures with appropriate concrete mixes would be where I would expect to see the tie with integral waterstop in use.


Daniel

 

[RHTPE]

Neoprene or PVC washers on a threaded rod are not effective waterstops.
After examining some 400 residential foundations over the last 4 years, my conclusion from my observations is that water will almost always find its way through the interface between the concrete and whatever form tie material is used. Proper concrete consolidation minimizes or eliminates the problem.
DTGT2002's (hey Dan!) taper tie suggestion is valid IF the 'fat' end is on the water side of the wall, and the hole remaining after the tie is removed is properly plugged.
Not knowing what OP is constructing makes it difficult to make a recommendation.


Ralph
Structures Consulting
Northeast USA

 

[abusementpark]

Hey Ralph, this is an 18” thick exterior concrete building wall that will be exposed to wind-driven rain. It will not have soil bearing against it, nor should it ever be submerged in water, save for an extreme flooding event.

 

[RHTPE]

AP - Since it's not against soil and ground water, the best method will depend on the forming system used.
Residential form ties do not (generally) have adequate break-back to fend off the eventual rust & corrosion.
Ties for commercial systems (e.g. SteelPly or Moduforms) can be equipped with 1" x 1" cones that provide a recess for grout. Stainless steel ties can be made but come at a cost and lead time.
Ties for Euro-style forms come in a variety of styles, many of which can provide ample means to avoid rust & corrosion. It will depend on the supplier as to what is available.
Fiberglass ties are ideal for an application on an above ground wall as they will never rust or corrode. But they also have their issues with regard to cost and suitability for the form system used. They are NOT compatible with residential style forms.


Ralph
Structures Consulting
Northeast USA

 

[nackra]

some options mentioned by RHTPE can be reviewed:

http://www.daytonsuperior.com/docs/...teformingaccessorieshb.pdf?sfvrsn=24f1d560_70