Rich Borglum - CreteFoamer Blog

Another use for Cellular Concrete

nospam@example.com (Rich Borglum) — Mon, 28 Jun 2010 13:04:38 -0500

Here is a news release about use of cellular concrete in bridge construction. The arches are precast standard density concrete, with an overfill (presumably up to the deck) of cellular concrete. Read the whole story by following the link.

Cellular concrete in bridge construction

What dogs know about life

nospam@example.com (Rich Borglum) — Tue, 15 Jun 2010 09:10:45 -0500

Here are some secrets of contented living that most dogs follow.

Never pass up the chance to go for a ride.

Allow the experience of fresh air and the wind in your face to be pure ecstasy.

Always greet loved ones with enthusiasm, even if they have only been gone five minutes.

When it's in your best interest, practice obedience.

Carve out your niche and let others know when they've invaded your territory.

Take frequent naps and take time to stretch before rising.

Run, romp and play daily.

Eat with gusto and enthusiasm!

Be loyal, no matter what.

Never pretend to be something you're not.

If what you want lies buried, dig until you find it.

When someone is having a bad day, be silent, sit close by and nuzzle them gently now and then.

Thrive on attention and let people touch you.

Avoid biting when a simple growl will send the message.

On hot days, drink lots of water and sleep under a shady tree.

When you're happy, dance around and wag your entire body.

No matter how often you're scolded, don't buy into the guilt thing and pout...run right back and make friends.

Delight in the simple joy of a long rambling walk.

Demo Day Report

nospam@example.com (Rich Borglum) — Thu, 10 Jun 2010 13:01:22 -0500

This week was another demo week for the CreteFoamer

Here's a photo of the driveway pour which was completed on Wednesday June 9. It was our intent to do a cellular concrete sub-base under the whole driveway, but city regulators would not permit that. They required the standard compacted fill under all the driveway that was on the right-of-way. On the rest, we used a 3" cellular sub-base (25 pcf) and a reduced density top cap (115 pcf - 5.5 inches thick)

Compaction of the cellular sub-base was not required! There was a materials cost savings, while still getting 3500 psi strength. The "garage end" load had about 7% air because we forgot to tell our producer "no air entrainment" when we ordered, so our density was lower than we intended. If we had chosen to check mix density before adding foam, we would have caught the error. As you can see in the photo, we used wire mesh for the whole driveway. City regulations required that the ROW portion was an Iowa DOT spec mix with no foam added and 800 lbs/Portland per yard. Normal 28 day strength for that mix is about 6500 psi. We used the same mix for the "garage end" load, but added the foam. We will finish the control joints and get a final inspection when it quits raining in "our neck of the woods" as many TV weather personalities, including Al Roker, seem fond of saying.

Here is a link to a 1999 article found on IrishConcrete.ie about Cellular Concrete for Road Construction.

IrishConcrete

I was just alerted to this video by Google Alerts. There are two quick images of buildings in Haiti which were not destroyed by the earthquake.

We are in current discussions with two groups who are rebuilding Haiti.

Facebook video --CLICK HERE - Cellular Concrete in Haiti

CreteFoam

nospam@example.com (Rich Borglum) — Fri, 30 Apr 2010 05:45:54 -0500

CreteFoam CMX complies with all ASTM C869 Specifications

A good foaming agent is important in producing cellular concrete. Bubble size, strength, and life are all critical elements. Our new foam, CreteFoam CMX, has just been tested to compliance with ASTM C869 standard specification. CMX development began in May 2009. During field testing, one user noted the "really fine tight bubbles" and found it to much more stable than the foam he had been using. The compliance testing was done by an independent laboratory which is ASTM recognized.

CMX has two polymers for superior performance. The flash point is in excess of 201F, which is important because flash points below 200F require shipping and handling restrictions. Dilution rate is from 1.5 to 4 ounces per gallon. In our 35 years of formulation of foaming agents which are used throughout the world, we have repeatedly "learned" that there is no single universal rate for dilution of any foaming agent. Water hardness, temperature, and other "water quality" factors determine the amount of concentrate required per gallon of water to make a "good" foam.

If you are involved in cellular concrete and would like a free sample of CreteFoam CMX, call Richway at 800-553-2404 (or 319-987-2976) and ask for Tony, Marty, or Rich.

DEMO DAY COMING

nospam@example.com (Rich Borglum) — Fri, 16 Apr 2010 11:45:17 -0500

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.

Myths

nospam@example.com (Rich Borglum) — Mon, 12 Apr 2010 13:56:17 -0500

Cellular Concrete Myths

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.

Interesting Information

nospam@example.com (Rich Borglum) — Mon, 05 Apr 2010 10:24:42 -0500

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."

Foam and CLSM

nospam@example.com (Rich Borglum) — Tue, 08 Dec 2009 09:11:29 -0600

Flowable fill, as it is often called, more formally known as Controlled Low Strength Material (CLSM), has an important place in infrastructure construction. It typically has a small percentage of cement (which may include fly ash), aggregate (usually fine), sometimes local soil, and lots of water. The water provides the flowability, but must be drained away at the deposit site, which can be a problem. Foam can be used in place of water to provide flowability and does not have to be dealt with at the deposit site. Furthermore, use of foam can create a lower density fill which put less load on the substrate below the fill. You may have to slightly increase the cement percentage to get required strengths, or just allow the foam to collapse at the deposit site and then be sure you have completely filled the deposit site. This will result in a "full density" fill. If you choose the latter approach, you need to use a "flash foam," which is different from our standard CreteFoam concentrate. Want to know more? Call 800-553-2404 and talk to Tony, Marty, or Rich.

The world's largest foamed concrete project

nospam@example.com (Rich Borglum) — Thu, 19 Nov 2009 14:06:17 -0600

Lying within the City of Bath World Heritage site, the picture-postcard village of Combe Down is
home to what is thought to be the world's largest single use of foamed
concrete, with the estimated final volume approaching 600,000 cubic meters
and due for completion by December 2009. {785,000 cubic yards]

Click on this link to learn more about this multi-year project in southwest England.

CLICK HERE

The concern is that the supports which were left during mining of the limestone were too small and too far apart to safely support the ceiling of the mine.

Two more CreteFoamer Skidmount units ready to ship

nospam@example.com (Rich Borglum) — Mon, 19 Oct 2009 16:18:54 -0500

Last Friday, October 16, these two skidmount Cretefoamers were "posed" and photographed before crating for shipment. The one on the left is a CFVT-8C-SM and the one on the right is a CFVT-20C-SM. Skidmount units include water tanks and gas engine powered air compressors (diesel available) to make a complete stand-alone package, ready to go to work. The "8C" has a foam output rate of 8 CFM and has a 100 gallon water tank. The "20C" has a foam output rate of 20 CFM, with a 300 gallon tank. Both can run continuously -- there is no pre-mixing and no guessing required. Rugged, reliable, and simple are three of the many words which describe Richway CreteFoamers. Unfortunately, these are both powder coated black and thus don't show up very well.

A Response to Some Questions

nospam@example.com (Rich Borglum) — Tue, 29 Sep 2009 13:09:10 -0500

Here's a response to some emailed questions we got this morning from a prospective customer in Europe. The questions are not included, but you can figure them out. Go to the "contact us" section of the main website www.CreteFoamer.com if you want any further information.

___________________________________________________________________________________
Your mix can include Portland cement and sand and aggregate as well, depending on dry density desired. We will be glad to provide a suggested mix design based on your desired density and strength. You will have to adjust this based on the materials you have available. Your production rate is one that we can meet with at least one model of our CreteFoamers.

We have two different foaming agents. Both of them will cost about $10 per cubic meter of foam produced. If you wish to make panels of 1/2 normal density, you will use about one cubic meter of foam per cu meter of concrete slurry in the mixer. Cellular concrete tends to set up more slowly than standard density concrete. You can add accelerator admixture to speed up the set-up time. Silica fume also speeds set-up, if you have it available.

You will mix a batch of material and then add the foam to it directly from the CreteFoamer as it is produced. The amount of foam you will need depends on the batch size of your mixer and the desired density. I am not sure what type of "normal concrete mixer" that you think will cause foam to be lost, but I do not think this will be a major problem. We have used a number of small lab mixers, as well as drum truck mixers and volumetric truck mixers. Ribbon and paddle mixers are also used. None of them seem to have a big effect on the foam.

Concrete density is determined by the amount of foam you put in each batch. You control this by the amount of time you run the foamer for a batch. The density of the foam itself is determined by the machine design, the foaming agent used, and the amount of foaming agent used. Our production sized machines have the ability to change the ratio of foam concentrate used, as well as the foam output rate. The density usually falls in the 3 to 4 lb/cubic foot range. (4 lbs/cu ft = 64 gms/liter) In our experience, it is important to have constant flow rate of foam and constant density, but if the density is in the 2.5 to 4 lb/cu ft range, the exact density is not critical. Using too little foaming agent may produce a foam which has the desired density, but not enough bubble strength and life to produce a good finished product. As the density of the concrete is reduced, it tends to shrink when too little foaming agent is used.

I know of no problems with steel reinforcement and cellular concrete. It is possible that the foaming agent could cause corrosion of the steel, but the amount of foaming agent per cubic meter of concrete is very low. I have not read or heard of any problems. The foaming agent is very similar to air entrainment admixtures. Air entrained concrete is commonly used with steel reinforcement.

We recently shipped a machine to Viet Nam which I think is going to be used in a plant similar to yours, but I do not believe the plant is completely set up yet.

I hope this has answered all your questions. Please email me with any more that you have or if I was not clear in my answers.
______________________________________________________________________________________

ICF's

nospam@example.com (Rich Borglum) — Sun, 23 Aug 2009 12:09:31 -0500

Insulating Concrete Forms (ICFs) continue to gain traction in concrete construction. We get asked about cellular concrete for use in ICF's with increasing frequency. "Will it work?" is the essence of the question. Short answer, yes.

With 110 to 120 pcf cellular concrete and the proper mix design, it is possible to get compressive strengths in the 3000 to 4000 psi range, which is more than sufficient for above ground residential construction. See earlier posts to the blog. Note too that the mix design does not have to be exotic, but primarily a low water and higher than normal amount of cement. Exact strength, as we have noted before, is dependent on local materials, batching techniques and mixing in addition to the mix design itself. It is the responsibility of the user to do testing of a chosen mix design.

At a recent demo day, we filled a section of ICF and later stripped away part of the form to view the fill we had achieved. As you can see, it was pretty good, especially considering that we did not vibrate and did only a minimum amount of tapping on the forms. Considering the flowability that foam adds to concrete, these results are not surprising. You'll add some (not a lot) of insulative value to the wall at this density. An R-value of .25 to .33 per inch would be typical at density of 110-120 pcf.

Conclusion. You can provide a good quality job and save money too with cellular concrete!

Stripped away section is in bottom photo..

Standards for 7-day and 28-day strength test results

nospam@example.com (Rich Borglum) — Wed, 12 Aug 2009 17:12:26 -0500

Here it is, direct from ACI, a discussion of 7 and 28 day strength. See our strength test discussion a couple of posts down.

>>> Start of ACI post

"Technical Questions - ACI Concrete Knowledge Center

Q. We test concrete cylinders for compressive strength. Most specifications that we see require a compressive strength of 3000 psi (20.7 MPa) and testing at 7 and 28 days. What ACI standard stipulates the percent of the specified compressive strength that the cylinder must meet in order to pass the compressive strength test at both the 7- and 28-day ages?

A. ACI 318-02, "Building Code Requirements for Structural Concrete," and ACI 301-99, "Specifications for Structural Concrete," contain standards information related to this question.

Section 5.6.2.4 of ACI 318-02 requires a strength test to be the average of the strengths of two cylinders made from the same sample of concrete and tested at 28 days or at the test age designated for determination of the specified compressive strength.

ACI 318-02 doesn't state a percentage of the specified compressive strength that must be reached at 28 days. In accordance with Section 5.6.3.3 of ACI 318-02, the strength level of an individual class of concrete is considered to be satisfactory if every arithmetic average of any three consecutive strength tests equals or exceeds the specified compressive strength and no individual strength test (average of two cylinders) falls below the specified compressive strength by more than 500 psi (3.45 MPa) when the specified compressive strength is 5000 psi (34.5 MPa) or less.

Results from the 7-day tests mentioned are usually not used for acceptance purposes, and thus there isn't a percent of the specified compressive strength that the cylinder must meet in order to pass the compressive strength test. Section 1.6.4.2.e of ACI 301-99, for instance, requires molding and curing three cylinders from each concrete sample and testing one specimen at 7 days for information and two specimens at 28 days for acceptance, unless otherwise specified.

The 7-day test result is used to monitor early strength gain and is often estimated to be about 75% of the 28-day strength (Kosmatka, Kerkhoff, and Panarese, “Design and Control of Concrete Mixtures,” PCA, 2002). Neville (Properties of Concrete, 4th Ed.,” Prentice Hall, 1995), however, suggests that if the 28-day strength is to be estimated at 7 days, a relationship between the 28-day and 7-day strengths has to be established experimentally for the given concrete. For this reason, he states that various expressions for the ratio of the two strengths (expressions that were discussed in the previous edition of his book) are no longer thought to be reliable.

Regardless of the reliability of the estimate for 28-day strength, 7-day strength test results are useful to the contractor and concrete producer as an early warning signal. With today's fast-track concrete-placement schedules, it's essential for the contractor and concrete producer to know when 7-day test results are low. Then suitable steps can be taken promptly to adjust batch quantities, improve quality control procedures at the job site, and ensure that sampling, molding, and testing of the cylinders are being done in accordance with ASTM applicable standards.

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To purchase PCA documents referenced above, visit the bookstore at:
http://www.cement.org/bookstore/

To purchase the book by Neville, visit websites such as http://www.amazon.com

Posted 2/13/06.

Disclaimer: Questions in this column were asked by users of ACI documents and have been answered by ACI staff or by a member or members of ACI technical committees. The answers do not represent the official position of an ACI committee. Only a published committee document represents the formal consensus of the committee and the Institute. " >>> end of ACI post

What is it?????????

nospam@example.com (Rich Borglum) — Mon, 10 Aug 2009 11:42:10 -0500

These are micro photos of foam in our R&D lab. These are illuminated with an LED light source, with different magnifications. We do studies of both bubble size and pore size in the cured concrete because of the importance of pore size in influencing strength of cellular concrete.