icf walls and thermal imaging 1

[vato]

Has anyone used thermal imaging of icf walls in order to determine if there are significant voids in the wall and or
honeycombing at the surfaces?

 

[Ron]

The insulation will mask anomalies in the concrete. Only exposed concrete would yield interpretive results with thermal imaging

 

[vato]

thanks ron,
I did come across an abstract on ground penetrating radar used to find voids in icf's and it was
apparently pretty successful. Cheaper to remove some foam.

 

[concretemasonry]

ICF's are somewhat notorious for making poor placement due to the narrow space for concrete to flow and be consolidated properly. Corners and under/around openings are prime areas to use as a general.

Unfortunately, the wet mixes and no need to reveal the wall face after pouring does contribute to some problems.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[vato]

When icf's first came out, it was required that an engineer be on site during the pour. This, of course, discouraged the use of them and now it seems like contractors with absolutely no experience pouring and placing concrete are building with them. I think we need some type of required inspection which involves removal of foam from top to bottom, at a few critical areas, in order to ensure correct consolidation. Or a magic camera.

 

[TXStructural]

Done properly, the top of forms below openings should remain open. I would also encourage the use of polycarboxylate viscosity modifier/water reducer in all ICF projects. Done properly, this will assure you get good flow, consolidation with minimal vibration, and even distribution of aggregates, while reducing labor and reducing the likelihood of ICF blow outs due to wet concrete and vibration. Polycarboxylate-modified concrete has been shown to hold the head of a second lift after the normal interval between lifts. It may be useful to do a wall in three lifts rather than two, and since it takes less labor and fewer people to place modified concrete, the costs should be the same or less.

That said, you always have the option of "poking holes" thru the foam with a small probe to spot check for honeycombing. Also, depending on the forms, tapping the foam should sound hollow if there is no concrete behind it over a larger area.

 

[Splitrings]

Thermal imaging does not penetrate. It simply shows temperature variations on the surface. Its possible if the voids were close enough to the surface there may be a slight temperature variation. No chance of penetrating the insulation as Ron pointed out.

 

[vato]

WOULD THERMAL IMAGING ACTUALLY WORK FOR EXPOSED CONCRETE OR WOULD I BE BETTER OFF SOUNDING WITH A HAMMER?

 

[Splitrings]

My guess is not. The surface of the concrete just in front of the anomaly would have to vary enough to be detected by the camera. I can try ours tonight.