use of silicate admixtures for slab moisture mitigation 4

[darthsoilsguy2]

More and more we're having contractors who want to use this admixture (at additional cost) for slabs-on-grade. A little background first for curious people less familiar... The product in the region is called Barrier 1 and it gets batched into the concrete. the concrete tester takes a photo of the vapor barrier and collects the cylinders and mails them to the admixtures lab. Then the contractor gets a nice warranty from the admixture provider that says the slab is under warranty regardless of any MVER or RH testing results. So with that warranty in hand the contractor can install their finishes (carpet, vct, etc...) without waiting for the slab to dry which is the warranty condition of the finishes that are being placed. The way the admixture is supposed to work is to make the concrete less porous in the hopes that the water that is trapped eventually emits out at such a lower rate that doesn't damage flooring materials.

Ok. So my position on this product is that i'm more interested in removing the water from the slab than i am having a manufacturer warranty that the slab will trap water well enough that we won't have problems. I'm bumping heads with contractors who want to consider this admixture the "industry standard"... even to the point that denying the product is considered a delay. Since most of the technical literature about construction materials are generated by manufacturers, it is hard to find references to cite about concerns over one product or another. So to the tip... i'm interested in independent studies and references that might support (or refute) my concerns. Anybody have any links?

 

[Ron]

dsg....thanks.

You are correct about the surface pH. That's why when we check for carbonation (usually 1/8" or less), we have to use a freshly broken piece of concrete (not cored or sawcut) to treat with phenolphthalein to check for depth of carbonation.

Agree with the SGH evaluation. They are top notch. I have consulted with them, for them and against them!

 

[dik]

Ron, i'm going to use that quote about experience until i'm dead.... here's a star for it.

I preferred his 'junkyard dog that chews concrete'... much better, but, inappropriate for this thread.

Dik