Self-Consolidating Grout Question

[StrucDesignPE]

We have a hollow 12"x12" CMU column on a project that we would like to keep for various reasons. Field inspection indicates the column is hollow. We need to grout it solid. I recommended a self-consolidating grout (SCG) with fine aggregate to ensure maximum flow into all of the cells. GC is asking if a premixed product would work such as this one:

https://www.euclidchemical.com/products/construction-products/grouts/cementitious/nc-grout/

I'm skeptical as it seems to have a higher flow rate, but not sure it is as high as it needs to be to be considered SCG. Also, since that particular grout is non-shrink, am I going to get expansion that may crack the CMU?

Thanks

 

[STrctPono]

I have used non-shrink grouts to repair CMU before both forming and pouring as well as filling ungrouted cells but it's probably not the best application for your project. Euclid does, generally, produces quality products. A few benefits of non-shrink grouts is that you always get a positive expansion, not really necessary for your application. The term "Non-shrink" is a bit of a misnomer but it seems as if you know that already.... As long as you allow the material to expand on one free side (like the top of the CMU wall, then it will not crack your CMU. Non-Shrink grouts are also super at gaining very high strengths in a relatively short amount of time. The one thing that I do not like about non-shrink grouts is their low durability especially when exposed to the elements. There is no coarse aggregate in these prepackaged bags (however, if you are willing to do some research and work with the manufacturer you may be able to extend the material with aggregate) and typically the fine aggregate is not much more than dust, not even sand. So you need to consider that.

Self Consolidating Grout is a good choice since it has coarse aggregate... not sure if it's your only choice but it would give you a good product in the end. How did you specify this? Just by pure name and strength or did you specify type of aggregate with with spread rate requirements? Self consolidating grout isn't just soupy grout (although many Engineers wouldn't know the difference). They add plasticizers and VMA's to achieve a high spread rate (~>18") and have no segregation within the material itself. There are prepackaged self-consolidating grouts out there.

It sounds like this is a small job (1 column?) so the Contractor obviously doesn't want to order a truck and can get this job done using prepackaged bags. I would approach this by counteroffering with a prepackaged self-consolidating grout option.

What are your access conditions like? Can you pour from the top or do you have to core a hole through the CMU near the top and birdmouth or pump in?

 

[wannabeSE]

I may be missing something. It seems like masonry grout is needed and the contractor is proposing non shrink grout. That’s like asking for house paint and getting car paint. Have you called Euclid to see if it will work?

Has the contractor already tried getting the self consolidating grout from typical bag mix suppliers/manufacturers - Sacrete, quikcrete,