Pete Free shares his thoughts on a concrete mixer for Haiti

Re posted with permission from Pete Free (We are honored to share this!)

Rebuilding Haiti with Stronger Concrete — an Intermediate-Technology Solution Offered by an American Company, Cart-Away Concrete Systems’ Concrete MD

© 2011 Peter Free

25 January 2011

It’s rare to find an entrepreneurial team with a solution to a real problem and the intelligence to clearly explain why the solution matters — meet Cart-Away Concrete Systems’ Concrete MD

Concrete mixer for Haiti

Measured Batching

What follows is an outgrowth of my concerns regarding:

(i) laggard Haitian reconstruction progress


(ii) the likelihood that rebuilding will recreate the previously weak concrete that failed so disastrously during the 2010 earthquake.

Bruce Christensen, general manager at Cart-Away Concrete Systems, contacted me in regard to one of my blog postings.  (I am not associated with him or his company.)  I had written about a Georgia Tech study that demonstrated that Haitian concrete is less than half as strong as American standards require.

Citation — the science regarding weak Haitian concrete

Reginald R. DesRoches, Kimberly E. Kurtis and Joshua J. Gresham, Breaking the reconstruction logjam: Haiti urged to recycle concrete rubble, Bulletin of the American Ceramic Society 90(1): 20-26 (January-February 2011)

Cart-Away Concrete Systems is trying to help the third world make adequately strong concrete

Cart-Away mounted an entrepreneurial effort to assist Haiti with concrete-mixing technology that would avoid the structural problems that so devastated the nation during the 2010 earthquake.

Two elements to this effort are unusual.  First, Cart-Away’s portable mixer appears to solve problems that Haitians face in regard to producing strong concrete.  Second, the company’s website does the best job I have seen in documenting the concrete-production problems that Haitians face.


Coincidentally, a few months ago an experienced brick mason and I donated our labor to build a comparatively small brick structure for rock-bottom cost.  The situation essentially paralleled cost and equipment constraints common in the third world. Construction took a few days.

We had to mix mortar by hand in two contractors’ wheelbarrows.  There were significant problems in properly measuring ingredient proportions and then mixing the resulting mortar thoroughly.

People without experience in this kind of work have no idea how difficult it is to achieve consistency between batches, or how much laborer strength and endurance it takes to adequately mix even one large wheelbarrow load of mortar.  Then try doing it all day.

Traditional Haitian concrete-mixing techniques are badly flawed

In Haiti, concrete ingredients are guesstimated.  Usually, they are mixed on the ground, where it is impossible to contain the materials in a controlled and repeatable environment.

When Haitians have access to a bicycle-powered mixer (in which ingredients can be properly contained), estimating ingredient proportions remain a problem and the bicycle operators’ varying muscular strength and cardiovascular endurance also come into play.

Here is a Spanish language video showing the two traditional Haitian mixing techniques.  People with construction experience will immediately recognize that it is impossible to turn out consistently strong concrete (or mortar) under these conditions.

Cart-Away’s proposed solution to Haiti’s concrete-mixing problems — Concrete MD

A video showing the problem that Cart-Away is responding to, and its Concrete MD solution, is here.  This is the most persuasive video of its kind that I have seen.

Notice, also, that tabbed links on the website do an excellent job of explaining the Haitian problems that Concrete MD solves.

Entrepreneurial efforts of this kind deserve support

Since I have not tried Concrete MD, I do not know whether it works as well as Cart-Away says it does.

But I do recognize a company that has the intelligence to explain the problem it’s going to solve, designs a solution that looks as if it works, and then capably uses the Internet to make people aware of its potential contribution to making things around the world better.

When an American company can do all three on behalf of the third world, I’m impressed and enthusiastic.

CementTrust is grateful that Pete is sharing the message of a better built Haiti.


About cementtrust

I am a director with Cement Trust and passionate about improving cement-based production in the poorest nations of the world.
This entry was posted in Haiti and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s