Will they ever trust concrete again?

What would frighten you enough to cause you to sleep outside in the street rather than in a perfectly good house?   What if you had survived a 7.0 earthquake and you had to make that choice?

Choosing a tent over a house might seem radical, but after witnessing the collapse of many of the homes and buildings in your neighborhood, you might lose trust. Especially as you realize that the same concrete that crushed friends and family is the material that built your home.

There are over a million people who are homeless following the quake, yet it is estimated that 1/3 rd of those in the tents have an undamaged home sitting empty. Many choose to camp out rather than trust the concrete.

The Haitian government and the World Bank are working to alleviate the fears of the people by sending engineers to inspect each home for signs of damage. When inspected and found OK, they paint a green symbol on the side of the house signaling the “all-clear” to move back in. Yet, many are still staying in their tents for lack of trust in the same engineering that caused the problem.

This fear of a common construction material like concrete is puzzling to those of us in the developed world. We don’t think twice about the stuff that holds up our homes and bridges our rivers, because we have learned to trust our concrete production system.

The sad fact is, in Haiti there aren’t many practical alternatives to concrete construction. The forests are long gone and they can’t afford any other alternatives, so eventually they are going to need to trust concrete again.

Concrete is very trustworthy when done correctly, so the key to building trust again is to make some radical changes in the Haitian concrete production processes.

But, the focus of the Haitian government and other groups is on the alternatives to standard concrete construction.

Aid organizations are currently exploring many trendy new building systems to rebuild Haitian homes. Even so, concrete will still provide the foundations for most of these systems.  Building a structure on top of weak concrete footings does not seem to be the best use of resources.

The fact is that thousands of Haitian workers know how to do concrete construction and just need some help to improve the quality of the materials that they already want to use.

Here are a few ways that the world can help Haiti trust concrete again:

1. Produce better sand.  Sands are used to produce concrete blocks, structural concrete, mortars and plasters. Most of the sand in the country has a limestone base or is from the beach. Both are poor choices for producing concrete and will decrease the life of reinforcing steel.  Investing in quality river-sand production will have a long-term benefit for the concrete production within the country. The bonus in this project is that the same improved processes for sand can also deliver better stone as well.
2. Use some of the aid money to subsidize the cost of cement. Portland cement is the most expensive component in producing concrete products. The high cost of cement forces many to cut back on the amount that they use in concrete production.  If all Haitian builders could afford to mix using the correct number of bags of cement, the concrete would be more trustworthy.
3. Rebar or reinforcing steel must be available and used correctly.  Not the rusty, smooth and junky stuff, but the steel like we use in many parts of the world.  It will probably need to be imported, but it must be done to hold the concrete together.
4. Get them some real concrete mixers.  There is no way that a good concrete can be achieved by mixing the materials on the ground. There are many good mechanical mixing solutions, so there should be hundreds of mixers working all around the island. Block production facilities should be mechanized and use good mixers.
5. Provide some simple engineered plans for building a safe home. They needed the details on how to bring it out of the ground reinforced with steel and with the right concrete to get it all done properly.

If we spend some of the generous donations from around the world to help the talented concrete workers of Haiti improve concrete construction, we could build back the trust that concrete deserves and get more houses built in a shorter time.  The tents would come down, the cement block plants would produce strong product, there would be good ready-mix concrete and thousands of homeowners would be living in safe housing.

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About cementtrust

I am a director with Cement Trust and passionate about improving cement-based production in the poorest nations of the world.
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One Response to Will they ever trust concrete again?

  1. T. Vail says:

    Is there a way to wash beach sand? I understand not using limestone based sand, but if the beach sand was free of salt, wouldn’t it work as well as river sand?

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