Concure Concrete Admixture

Archive of Older Topics Archive - Product Discussions #3
1

This product was brought to my attention yesterday. Concure Products, Inc., produces a concrete admixture, a vapor barrier and a flooring sealant, waterproofing products for the concrete and floor covering industries. They claim to have no product failures in 16 years - a 100% success rate. The admixture and sealant primary component is silicate which reacts in the concrete, forming a gel. The admixture densifies the concrete, typically increasing strength. Concrete color doesn’t change, the steel is actually more protected, there are no negative reactions with other admixtures. There’s a 2 year standard construction warranty against moisture related failure including finish floor materials and labor and it’s compatible with all floor coverings and coatings. (and other benefits are listed)

The claim is, use this and you don’t need a vapor barrier under the slab.

The vapor barrier is two-step and designed to stop de-bonding due to moisture. It, and the sealer (used on green concrete) are designed to be used for concrete that didn’t use the admixture, if I’m reading the material right. There’s a 10 year warranty on the vapor barrier.

This - no under-slab vapor barrier - sounds too good to be true. Has anyone had experience with this(these) product(s)?

2

How much time do you have?

I did some looking into these types of products a while back, and came away with the following:

Concure makes several products, some of which are those referenced above:
- an admixture
- the topically applied liquid sealer (what they call their “Step A”)
- waterproof cementitious coating (basically, an Ardex-type of product that they call “Step B”)

Manufacturer’s product data could be clearer, but the installation sequence seems to be following:

- Shot-blast concrete substrate, 
- Step A topically-applied sealer is applied to the  concrete and allowed to dry, 
-  Step B cementitious underlayment is applied and allowed to cure / dry.

Some comments and opinions:

  • I do not believe the system negates the need for a separate under-slab sheet vapor retarder. I think it prudent design to install one anyway.

If you do the following -
- Provide a properly installed under-slab vapor retarder,
- Provide low water/cement ratio concrete (0.45 - 0.48),
- Provide for proper moist/damp-curing (not wet) of the concrete slab,
- and sufficient time for the slab to dry before the flooring is installed,
. . . the Concure (or any other) system should not be required.

  • The Step B cementitious underlayment is what provides the barrier between the sealer and flooring adhesives (since most resilient flooring manufacturers say that their products cannot be applied to sealed concrete). It also keeps the shot-blast surface irregularities from telegraphing through the finish flooring.

  • The system is designed to stop moisture only up to 10 lbs. It can’t be installed if the MVETR exceeds that amount. There are other products on the market that can be installed under conditions of unlimited MVET rates (and that have a 15 year warranty).

  • The 10 year warranty seems to only cover defects in material. I could not see where it covers failure of the product / system to stop moisture vapor transmission (but I may have old literature).

There are basically three families of topically-applied vapor retarder / barrier products:

This type of sealer (not sure of the generic name):

  • Concure
  • Creteseal CS 2000
  • Concrete Moisture Solutions

Epoxy-type:

  • Ardex
  • Koester

Synthetic resin polymer based:

  • Advanced Moisture Solutions
  • Floor Seal Technology

There’s also Aquafin, but I am unsure which family they fall into.

Corporate leadership of some of these companies seems to be rather fluid, with some folks leaving one to join / head up another.

Hopefully, some others more knowledgable could weigh in.

3

It’s only with the use of the admixture that the manufacturer states “Eliminates plastic vapor barriers”. And with the use of the admixture, the curing product is a no charge item. Parts A and B refer to the topically applied Vapor Barrier; you’re right about the 10 year warranty for that. The admixture carries the warranty that includes replacement of any damaged flooring from moisture migration through the slab.

4

Just remember ALL concrete cracks and they blame any moisture extrusion on having the wrong expansion joint design, and most expansion joints should be on grade and the full depth of the slab. The product might stop vapor from entering a structure, but I don’t see a WVT rating on the concrete, accept for the 10 lbs. of moisture stoppage with these admixtures. I agree with David Combs, that these systems should not eliminate the need for a good quality .15 mil vapor retarder.

5

Harold, I hope you mean a “15 mil” vapor retarder instead of a “.15 mil”. If it were .15 mil, you just might as well put tissue paper down.

6

Lynn,

Concure update: We did have one project where the admixture was used. Apparently, the decision to use it was the owner’s, based on the presentation they attended by Concure.

I received the following info from the project architect:

“. . . it went back and forth for so long that half the building was poured without it. The rest was poured with it, and from the contractor’s comments, they hated it. It was difficult to work with in the dry environment (New Mexico), because the top dried out so fast that the insides of it was like riding on mayonaise.”

“By the way, the contractor tried this stuff on some trial pads even before putting it on the building. After if being fully dried, it ended up curling up on the ends by more than an inch.”

I also somewhat recall it being rather expensive.

DRC

7

I just read over the original entry which said it was a gel like substance which is common with High Solids Sodium Silicate products that several manufacturers have copied the Ashford Formula treatment. If these products are applied wrong, like anything else it will not get the desired results. If there is a reference to “if splashed on glass remove immediately” in precautions then it is a sodium silicate product, and like the current ASTM- C-309 specification reads " This spec is not intended for sodium silicate" which means it does not form a membrane, but they do a nice job in hardering of the top 1/8" of the concrete slab.