CreteFoamer Blog

The first demo day of the summer is coming ---Friday April 23, 2010

Join us at 10:00 at the Richway factory at the northwest edge of Janesville, Iowa.  (504 North Maple Street)

We will be doing a demonstration of slab jacking with cellular concrete. (Look down 2 posts to see the "results" of a test we did last week)

We will also be doing some cellular backfill and "showing off" a sidewalk poured in the summer of '08 using a lightweight cellular sub-base.  This sidewalk has not cracked, even though it has had a tandem axle steel scrap truck drive over it many times.

We will be discussing how cellular concrete backfill can provide improved quality and save money by the eliminating the labor cost and time for compaction.

See the beginning of instrumentation for our thermal insulation study.  This will be a 12 month outdoor --- in the ground--- study.  As planned, there will be 20 thermocouples used for monitoring temperatures. 

Depending on time available and the interests of our visitors, we may be doing some lab mixes of magnesium oxide (MgO)  based cements.  These are rapid setting and have high strength.  On the downside, they have potential for dissolving in water over time, so MgO cement based concrete is not recommended for exterior structural applications.

Famous Dave's Bar-B-Que sandwiches at noon and CreteFoamer tee-shirts.

See our new 4000 square foot R&D area and tours of the factory if you want. Finally, we will answer any questions you may have. 

I found this on a website this morning. I consider it to be another myth about cellular concrete.

"Strength and Reliability
Cellular concrete is an almost ageless and everlasting material and is not subject to the impact of time. It does not decompose and is as strong and durable as rock."

This statement was on the website of a producer of cellular concrete equipment in a country other than the USA. In lower densities or with some mix designs, it may decompose and is hardly as "strong and durable as rock." Cellular concrete has a definite role in construction of infrastructure and in building construction, but it is important to recognize where NOT to use cellular concrete.

The same website went on to state:

"Trials undertaken have shown that the closed cell air bubble structure produced by the foaming agent creates cellular concrete with a very low water absorption rate."

"The higher the air content the higher the water absorption figure with a fully submerged sample of mid density (770 kg/m3) foamed concrete absorbing just 13% of water by weight over a 10 day period. A dense heavy weight concrete block submerged for the same period of time absorbed over 50% of water by weight." [770 kg/m3 = 48 lbs/cubic foot)

This flies in the face of our testing at Richway. Cellular concrete, when submerged, absorbs water --- period. You still have the cement and the capillaries to carry the water to the tiny tanks (bubbles created by the foam) for storage. It is a popular myth that cellular concrete does not absorb water and this myth keeps being repeated.

In March 2009, two of us from Richway were doing a presentation about cellular concrete for the Wisconsin chapter of ACI. The question about water absorption was asked and we stated that it did/does absorb water. Our statement was confirmed immediately by Prof. Konstantin Sobolev, the (then) newly elected Chairman of the ACI 523 (Cellular Concrete) committee. (He is a materials professor at the University of Wisconsin - Milwaukee and was attending the meeting.) He gave a short explanation of the mechanism of water absorption for cellular concrete.

Here is an interesting paper listing some uses of cellular concrete.

Click Here

On their website they say 




"Cematrix is a manufacturer and supplier of technologically advanced cellular concrete products with applications in a variety of markets, including oil and gas construction and infrastructure construction. It is headquartered in Calgary, Alberta."