Pump Skid Grout Recommendation

[mot1h]

We are working on vibration problem for a 2500 hp skid mounted pump-motor assembly. The skid has 12" deep cavities between the top plate and bottom plate, for filling with material to stiffen the skid and increase the mass. The cavities have only had sand fill so that the skid could be relocated. To provide more stiffness, we wish to fill them with grout now.

The side runners are 16" WF, the intermediate crossmembers are 12 WF, and the top and bottom plates are 1/2" forming the 12" cavity.

What grout products have been specifically made or successfully proven in this usage? Cost is of course a consideration. We are leaning toward cementitious grouts due to cost but are open to epoxies or other resins if necessary to do a good job of resisting vibration.

 

[motorman]

Unfortunately, there are a lot of site related considerations that must be understood before a recommendation can be made. The following sites are a good source of information on the aspects of grouting that must be taken into account when planning a grouting project.

http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-1-3500/c-2.pdf

http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-2-3506/c-13.pdf

for some ideas on designing the forms

http://www.masonanaheim.com/b/b104.htm

for some typical machinery grout data sheets

http://www.kcccorrosioncontrol.com/pdf/technical_bulletins/GT4000.prn.pdf

http://www.mbtfeb.co.uk/htmfiles/mflo648g.htm

 

[jheidt2543]

Motorman has given some websites to check out, which I intend to do too. However, my understanding of your question is what to fill the cavities with to add mass to the steel base, instead of the sand you are now using.

The first place to check is the pump manufacturer. They surly have a recommendation, maybe even a requirement on what to use to preserve their warranty.

Secondly, why can't a normal weight 4,000 psi concrete mix with pea gravel be used? At $60-$70/cy vs a grout product at $34/cf (and up) the concrete would certainly be less costly. In this application, I don't think you are worried about shrinkage in the concrete, just the added weight. When grouting between a machine base and the floor/foundation, where you can not tolerate any shrinkage, then a non-shrink, structural grout is required, I don't think that is the case here.

But let's check the websites noted!

 

[mot1h]

Dear motorman & jheidt2543;
I appreciate both of your replys. I printed the grout information and passed on to our civil engineer. However, I am still looking for someone who has actually applied a specific grout to this application successfully. In other words, where a skid vibrated and the vibration was dramatically lessened by having filled the skid cavity with a particular grout.

I believe that a non shrink (and non-expanding if that is possible) property is probably as critical to this application as it is under machinery. Vibration amplitudes are on the order of thousandths of an inch, and as such continuous contact between the grout and the steel is essential. If the steel can shift before making contact with the grout mass, the grout can stay still while the steel occilates, I am afraid. Much like pulling a table cloth out from under dishes. If the acceleration is short term enough, the grout will not necessarily accelerate at the same rate the steel does, and its mass will not be fully effective. Also, we want the grout to stiffen all of the steel joints essentially, causing the skid to act as one solid mass, not several hinged joints.

 

[jheidt2543]

mot1h,

The property that makes non-shrink grouts non-shink is actually metalic filings (metalic grout) or chemical additives (non-metalic grout) that are added to expand the grout as it hydrates. Then as the grout dries, it shrinks back to its original volume, therefore a net no shrink.

I think if you where to contact a grout manufacturer, like Master Builders or Sika, they would be able to help pick a specific grout product for your application.