How did you apply your non-shrink grout?

[sedonas]

I have unsuccessfully applied non-shrink grout to a 10mm gap under the base plate. We put water on the pail and put the grout.. we stirred them until they were flowable consistency.. then we poured it on the form works inlet (with outlets for air to go out) around the base plate. As we poured it.. the heavy part very quickly settled and only the very liquid part was on top of the pail. The next day when I removed the form works.. there are voids and it was so soft that we were able to remove it by bar.

Did you use electric stirrer to mix it or by hand.. when you first tried it.. were you successful? What technique did you use?

 

[XR250]

What consistency did you mix it to? It should be like pancake batter.

 

[sedonas]

flowable consistency.. but very quickly.. the paste went to bottom of pail after 2 minutes... did you stir and apply it under 8 minutes? Because it appears it sets after just 8 minutes.. did you use electric stirrer?

 

[Ron]

A 10mm gap is extremely hard to grout. You will likely need to drill a hole in the top of the baseplate, form the sides around the baseplate and then squeeze the grout through the hole. Drill two or three opposing holes away from the filler hole to let air out of the gap as it is filled with grout. The fill hole should be about 15mm or larger in diameter. The smaller air holes can be 5mm or so.

You mix the grout and immediately put into a bulk sealant gun and squeeze into the larger hole. If you don't have a bulk sealant gun, you can actually use a pastry piping bag with a plain nozzle. Work quickly as the grout will set up quickly as you've noted.

 

[sedonas]

Ron. I tried similar to the following.. won't it ever work?

https://www.youtube.com/watch?v=Q3V1dqyGgck

When trying just to get the right flowable consistency.. it reached 8 minutes and grout seemed to start to harden and sink.. would you know any none non-shrink grout material that would give enough time and flowable for this small gap?

 

[Ron]

Grout is fluid enough. Cut your flow length in half by feeding from both sides simultaneously . Drill an air hole near the center of the baseplate to let air escape and also to verify that grout got to center of plate.

 

[Brad805]

Is this skylight or XKN under yet another name? Seems likely given this name has only two posts. If not, my apology.

 

[sedonas]

Grout is fluid enough. Cut your flow length in half by feeding from both sides simultaneously . Drill an air hole near the center of the baseplate to let air escape and also to verify that grout got to center of plate.

Tomorrow I'll call Sika and let them recommend installers who are experts with great experience who can do it with tools. It takes too long just to stir it to get the flowable consistency... but then just when about to apply it, the heavy part set and went to bottom of pail. We didn't use any electric stirrer or bulk sealant gun but just stick to stirr.

Another idea. If Sika doesn't have experience with this complicated operation themselves. What if we had the plate sealed with waterproof putty and injected with epoxy instead of grout. Have you heard of base plates that use epoxy bedding instead of grout bedding.. we can't use epoxy grout because this can't be injected hence must be pure epoxy.

With uniform epoxy beneath the base plate, we should remove all side shims after a week and the plate would be in full contact with the epoxy and concrete.. but will take greater strain to reach the stress. Can you see or encountered negative effect of this?

 

[hokie66]

Your segregation problem is probably due to inadequate mixing. The Sika instructions say "DO NOT MIX BY HAND". If you don't have a mechanical grout mixer available, you can't use pourable grout.

 

[sedonas]

Your segregation problem is probably due to inadequate mixing. The Sika instructions say "DO NOT MIX BY HAND". If you don't have a mechanical grout mixer available, you can't use pourable grout.

I'll keep this in mind, the worker even used his bare hands to stir it (later ended up with swollen hands). The next day he had to remove all the bad grout under the base plate using rebar and hammer under the rain (because I fear the grout may get harder if attempting to remove longer)

Also how we did the mixing is get 1 liter of water in pail, then add the grout little by little as it is stirred to get that sticky consistency. This consumes so much time and the critical 8 minutes has passed.. I guess what you do is to put the grout and water in measured cup at same time and stir quickly. This may produce more consistent results. But I don't have any confidence anymore because I can't afford another failed attempt so I'll let Sika do it (if they do it at all) if they have experienced with 10mm gap.

If not. Can you see any problem with pure epoxy injection under watertight putty covered formworks? I can see initially that it will take more strain to develop the stress. This can result in the plate bending more and possibly put the anchors in tension faster. What is your experience or others on this?

 

[hokie66]

No experience with pure epoxy used as grout, and I would not allow it.

 

[sedonas]

No experience with pure epoxy used as grout, and I would not allow it.

Ok. do you know of any non-shrink grout that sets longer like 30 minutes.. why do they set so quickly in less than 10 minutes?

I need a load transfer material with rating of at least 200 (yes just two hundred) pounds per square inch (psi). Can you think of other material with modulus of elasticity close to concrete?

 

[Ron]

Agree with hokie66...would not allow pure epoxy as grout. There are some sand filled epoxies that are used as grout; however, they are not capable of such a small gap.

Try BASF Masterflow 1205 grout. It is cementitious, non-shrink and has an extended set time.

Stop trying to think of other materials. Properly applied grout will work for your application. As I said before...feed the grout from two sides to cut your flow length in half and drill at least one hole in the baseplate to allow air to escape.

You've been given appropriate advice to accomplish this task.

 

[sedonas]

Agree with hokie66...would not allow pure epoxy as grout. There are some sand filled epoxies that are used as grout; however, they are not capable of such a small gap.

Try BASF Masterflow 1205 grout. It is cementitious, non-shrink and has an extended set time.

Stop trying to think of other materials. Properly applied grout will work for your application. As I said before...feed the grout from two sides to cut your flow length in half and drill at least one hole in the baseplate to allow air to escape.

You've been given appropriate advice to accomplish this task.

Ok. Note the dimension of the plate is 19 x 19 inches.. what's the threshold size when the method you mentioned would no longer work? for example.. for a 1 meter x 1 meter base plate with 10mm gap.. it should still work?

 

[Ron]

There is no threshold size. It is whatever size you can force the grout under and achieve proper coverage.

 

[sedonas]

Ron. We don't have BASF Masterflow 1205 grout locally.. only Sika grout... I have tried both Sika 215 and 212 (any other that is slow to set like BASF). Did you first put them in container and water and immediately mix together with electric stirrer under 5 minutes? I don't know if the solid material that settles is because we don't use electric stirrer or it hardens after 8 minutes. In your experience.. how many minutes before it hardens?

 

[pete600]

I used to be a contractor (concrete sub) and I often installed grout below the base plates. I never had this issue but my first thoughts are that on of the following may be the issue:
1)the material was inferior (maybe a bad batch or damaged by moisture contamiation)
2)the grout was not mixed properly
3)the temperature was too low at placement

I would not use epoxy.

The grout should be flowable & mixed very well.

use a vibrator or hammer (by tapping on the base plate) to help get the voids out.

 

[Ron]

Sika 212 is fine for your application. Follow Sika's instructions exactly to get the flow you need. Place the grout within 15 minutes of mixing. Full set time should be several hours. Use a mechanical mixer.

Note; however, that Sika does not recommend a grout gap of less than 1/2". Yours is slightly less than their minimum.

Now...just go do it!

 

[sedonas]

Ron. Actually we have done it 5 times already. But not the holes on top because we have to spend time drilling thru over 15 mm of base plate.

But other idea. Tomorrow the contractor will (last chance) lift the baseplate and steel up. So the concrete pedestral is directly open. Have you experienced using a formworks and just pouring the sika 212 on the opened concrete til it levels.. then the next day lowering the base plate and steel over the grout. Would there be 100% (or at least 80%) contact or won't it work?

 

[hokie66]

There are actually a few different Sika 212 grouts. The one I am familiar with is Sika 212 HP. That one which says "do not mix by hand", but it also is for gaps as small as 10mm. I think you need to get Sika to come and show you how their product is to be used.