Im going to be pouring the concrete in my ICF'S  in a few days and wanted to get some techniques or tips on consaladating my walls, i have 6" Buildblock Icf's,the walls are 10' tall, the house is in Florida. im going to be using a wall banger but not exactly sure the correct way to consaladate the walls, should i just hit the outside of the wall? or inside and out? 1 sec per sq ft? any tips will help. Thanks

I am guessing that this is your first time pouring ICF walls?

If so, I would recommend that you get someone on site from your ICF supplier or elsewhere several hours before the pour (to make sure that the ICF walls are properly braced, helpers are briefed on their roles in the pour etc). Also you can never have enough help onsite during a pour.

Above all, I suggest that you do not rely on external methods for consolidating the concrete. Find yourself an internal vibrator with a 1" pencil head and if possible designate someone with experience to perform the vibration.

It has been demonstrated many times that one should never rely on external vibration - I cannot emphasize this point enough!!!!!!

I agree wholeheartedly with TerryJR.
Internal vibration is the most (only) reliable way to insure good consolidation when used properly.

Groundup,

TerryJR and bnc_skc are correct. There is no hard evidence that any type of external vibration transports air out of the wall. For this is what you are trying to do when you consolidate concrete. The only evidence I have seen is anecdotal and hearsay, I have never seen any type of scientific study that recommends external vibration. I know I know there are lots of people who say they have removed the foam and everything looked great, but my question is what did it look like around the rebar and inside the concrete? Scientfic study says it will will be substandard. My question is would you do brain surgery on yourself to save a dime or would you hire an expert to do the job right. Because it sounds to me like you are endeavoring to build, what is considered by most to be, your biggest investment on a shoestring budget and "wall banger". I would say hold off your pour until you get a qualified person there on a properly sized vibrator for your job.

ICF Contractor

any experenced ICF workers in the tampa area that want to help with the pour? experenced consaladating operators? ill pay of course, let me know

Groundup,

I wish I could help. But I am up here in sunny Seattle. Hope everything goes well.

ICF Contractor

Put off the pour til you find someone with experience.  Internal is the only to get success. 

 

 

Im going to go ahead and rent a 1" pencil vibrator and do it myself, im pretty sure i can handle it, any tips that anyone wants to add would be appreciated, im going on what i read ,every 4 feet drop it down and pull it up about 1 foot per second and on the second lift go down 6 inches or so into the first lift and follow same procedure, i should be a pro by the time im done.

Watch the corners, dont over vibrate them or you could have some problems. Spend alittle more time around each window and door opening and any where you have long lentels. Go in fast with the vibrator and pull out slow. When we did my house (As an owner builder) we had two 15' 3/4" vibrators. We put thevibrators in every 6 inches. We did not have a single problem. Just make sure you have alot of people to help. Use the wall tapper person to tell you how high you have poured so far. You can also tell if you are vibrating good enouh by the fluid seepage out between the joints of the block. Good luck

I'm not sure where you read that you should drop it down every 4 feet. That is way too wide a spacing. Check with the vibrator manufacturer. They should have a table or chart showing the diameter of influence for their vibrator motor/head combinations. Use the diameter of influence listed for your vibrator to determine the spacing between drops.

Here's a link to one manufacture's web site showing the chart I am referring to. http://www.minnich-mfg.com/1500.html

The chart shows that you should drop the head every 6" for a 3/4" head. From my experience, that may be overdoing it a bit and would be a lot of work too!. I have found that with a 1" head, dropping it every 12-18" does a good job. Keep it moving, don't let it sit and vibrate in one place too long.

You need to stay as close to the pump as is possible. The larger the head the greater the area of influence. We use a 1" to 1.25" head always. The 1.25" usually gives us the ability to vibrate every other core. sometimes if the re-bar will allow we go to a 2" head. Much better consolidation and instead of having run 2 vibrators to keep up we can use only one. Always fast in slow out. Never vibrate the same lift again. 4' lift, 4' vibration, next 4' only vibrate new lift.

Hey guys, everywhere i call to rent one only have the 1 1/2" heads, will that work?

 

Groudup,

I have never used the form you are using, but I have a friend who has used them and had success with vibration. His only issue was uplift in the corners and the top row. This can be easily rectified by using three strips of 1 inch nylon reinforced packing tape on each side of the corners from top to bottom. as for the top row; three strips of tape inside and out per block taping from the top row to at least half through the row below. Another method for the top row is to ziptie the top row to the row below. I think the 1 1/2 vibrator should work fine with a 5-6 slump.

ICF Contractor

Groundup,

How did your pour go?

ICF Contractor

Im still stalling, i started helping my buddy with a copper roof job and when im done with that im going to pour, ill let you guys know how it went

I just used a 1.5" vibrator on BuildBlock and had no trouble at all. The gable wall's went up 20'.  That was fun!

Tom:

Before you get too far with the large vibrator bit, can you please extrapolate on the mix you are using and why it is important.

Mark Ross

 

Where are you located. We may be able to pour it for you.
Regards,
Joe
RFB inc
5760 Youngquist Rd #3
Ft Myers, Fl. 33912
239 337 2006
239 337 0219
www.rfbhomes.com

Mark, At your request.

Vibrator used was an Oztec 1.8. Always go fast in slow out. Do not re vibrate the last lift. If you are pouring 4' deep only go over the first 4' once. Keep your concrete between a 5" and a 6" slump. You must be familiar with slump. Don't rely on the concrete company giving you what you order. I always order dry, about a 5" slump, and add water at the site. Learn to recognize what slump you are receiving. I have a slump cone and used it often when I was starting. No fly ash just Portland, rock, water, sand. Unless I have tons of re-bar or a 4" block I use #67 stone. It's a standard 3/4" top size stone. Large by most peoples standard. Make sure your block is well supported. It was my vibrator but you can rent them. I have rented Stow, Wacker, and others when needed. A 1.25" would be safer for your first time but a 1.5" is easier to rent.

I am running my electrical wire now after my pour and using a hot knife to get the wire in. My ICF supplier (who did the pour) claimed up and down that he didn't need an internal vibrator since he used a stronger (4000psi) mix with a wetter mixture (6" slump). I foolishly didn't push the issue. I have found three or four voids so far - who only knows how many more there will be. I cannot stress enough to vibrate your walls internally.