That quote is in the paragraph about spacing and evidently doesn't apply to the lift rate. But no doubt that if you go all the way to approximately zero slump (SCC), you don't need any vibration. They should be more precise and give a full table of slump vs vibration needed.

Posted By jonr on 03 Jul 2013 05:12 PM
That quote is in the paragraph about spacing and evidently doesn't apply to the lift rate. But no doubt that if you go all the way to approximately zero slump (SCC), you don't need any vibration. They should be more precise and give a full table of slump vs vibration needed.

It talks about the sphere of influence. Just as the head effects an area wider in higher slump mixes so it also effects areas high and lower. So if the head is moving concrete 12" a head of it instead of 6 inches that means you can move at twice the speed.

Anybody that uses SCC in ICF must have a death wish!

My understanding is that the lift rate is based on how fast a bubble rises, not sphere of influence. Available information is pretty vague as compared to most concrete specs.

banging on the wall does work, but it is not as effective. a small battery powered vibrator is the ticket. that's all you need and the mix is also very very important as stated above.

Posted By Midsouth ICF on 03 Jul 2013 05:53 PM
  A small battery powered vibrator is the ticket. that's all you need and the mix is also very very important as stated above.

Where did you find a small battery powered vibrator? Googling just shows up the xxx sites!

If you have an URL I'd appreciate it.

Thanks

Dewalt has one that has a 4' shaft. Makita has one with an 8' shaft.

They both have 4 foot shaft. no difference in them. I do know the Makita one can take beating.

Thanks, I've found both now, the De-Walt is only 4 ft, Makita is available with 4 ft or 8 ft shafts.

I'm looking to buy the 8' Makita , BVR850Z 18V LXT, the best price I can find on the 'net is US $329.00 with no batteries/charger or $539.00 with 2 batteries and charger.

I run a Milwaukee only site so the batteries would be of no 'other' use, but will probably order one for the current Quadlock Job.

My guess is that the limited HP of a small battery operated vibrator means it has a small sphere of influence - gas powered would be a step in the other direction (more HP). But anything allows one to say "yes, we vibrated". What the world needs are clear ICFs.....

Posted By jonr on 04 Jul 2013 10:12 AM
My guess is that the limited HP of a small battery operated vibrator means it has a small sphere of influence - gas powered would be a step in the other direction (more HP). But anything allows one to say "yes, we vibrated". What the world needs are clear ICFs.....

jonr,

A clear ICF with plenty of R-value.  Not being able to see inside a finished ICF wall allows contractors to avoid vibrating.  A stiff mix and a lack of vibrating can lead to voids in the wall but the homeowner may never know.

Some of my projects have used ICF walls but now I am moving to walls with concrete on the outside where it can be seen and serve as the finish.  No reason to flame me.  Each technology has to stand own its own merits.

Question I have is, after you pour the walls and then pour the base, how do you take care of the gap between the two if you are not inserting a liner and are using plaster or some type of spray.

voids in the wall but the homeowner may never know

I agree, ICF isn't great for "trust but verify". Maybe one could put specs into a contract. Ie, slump, psi, pea gravel, HP and head size of the vibrator, spacing, withdraw rate, etc. Conservative values, not seat of the pants "it doesn't need much vibration because....".

As discuss in a different thread earlier, there are a number of ways to verify the integrity of an ICF wall but if the homeowner/gc/engineer checks to make sure that the mix is right and that it is being vibrated they will avoid almost all issues. Stiff or waterery mixes need to be adjusted or sent back.

I personally don't see any use for a four foot wand on an eight foot wall. Are you going to cut ports in every other cell space? Even an 8' is not really long enough.

Alton - not to flame but ••• why let the outside temps into the wall when you can stop them on the outside face? Might not be as big a deal for you as for me with our different design temps but I think in any climate using the mass to your advantage makes sense.

Stiff ... mixes need to be adjusted or sent back.

Just add water :-)

FBBP,

I agree with you about using the right mix and proper vibration.    Lately, I have found a few contractors that are willing to vibrate walls and pay extra for a better mix.  I am finding that fly ash is a great ingredient to add to the mix.  Among other things, it makes the below-grade walls more water resistant and also eases pumping pressure.

I also agree about not letting outside temps into the wall and about using mass.  One technology that I have found that works well in my climate is SCIPs.

Question I have is, after you pour the walls and then pour the base, how do you take care of the gap between the two if you are not inserting a liner and are using plaster or some type of spray. Or some people might call this a cold joint. Anyone?

it makes the below-grade walls more water resistant

Is that something you found on your projects or something you learned somewhere else?

I'm a big fan of fly ash - it really helps ICF mixes.

Fly Ash or Slag, whatever is available in your area

pjf

Use a waterstop, preferably a 6" piece, 3" into the slab/footing, the other 3" into the walls

as well if the finishes are done correctly you should not have any water intrusion/escape at the joint, but it can happen so use waterstop

Posted By ICFHybrid on 04 Jul 2013 04:50 PM

it makes the below-grade walls more water resistant

Is that something you found on your projects or something you learned somewhere else?

I'm a big fan of fly ash - it really helps ICF mixes.

I have seen mixes with fly ash flow better.  I understand that the shape of fly ash particles act like ball bearings to reduce friction during flow.  Technical literature speaks about how the small particles of fly ash fill in the voids between larger particles to make the concrete more water resistant.   Fly ash can replace some of the cement.   Ready mix companies in my area can include fly ash in their mixes.

Here is a link to a short article about fly ash in concrete:  http://flyash.sustainablesources.com/    A quick google search will reveal many more links.