Death by a thousand shovels

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It was Tuesday,16:53 local time in Haiti when the January day was rocked by a 7.0 magnitude quake. On that day, and in the days that followed, 52 aftershocks of 4.5 or more rattled down buildings and homes with crushing force.

The numbers continue to be unbelievable;
An estimated 230,000 people lost their lives, 300,000 were injured and 1,000,000 were made homeless.

If we are looking for a definition of sadness and despair, we can find it today in the images of tent cities that include 97,054 tents and 681,490 tarpaulins.

These huge numbers can be avoided in the future if we can stop people from killing themselves with shovels.  

The shovel is a remarkably simple and useful tool, but in the hands of the poor it causes much of the crumbling devastation which we witness in every natural disaster.  We say that earthquakes don’t kill people, but that the buildings do.  Yet, we never blame the shovel, and we should. You see, shovels in cement are the overlooked enemy of safe structures in Haiti.

Cement is the most consumed product on earth, after water. In the right hands, and with the correct processes, it can build the strongest structures in the world. But when used incorrectly it offers a deadly false sense of security to those who trust it as shelter.  To the poorest nations, cement is the most cost-effective material to produces concrete foundations, concrete blocks, masonry walls and roofing slabs. In many cases, concrete in one form or another is the only reasonable solution to lasting shelter.

Unfortunately in all too many cases the cement is mixed into concrete using a shovel.

Blaming the shovel alone is not completely fair, but the shovel represents a part of a chain of events which regularly ends in tragedy.  The shovel partners with poverty to produce the problem.

Concrete is a mixture of Portland cement, water, sand and stone.  It is not a complicated recipe to follow, yet when we add in poverty we begin to create some issues.

The first issue becomes the cost of Portland cement. The price of one bag of cement is equal to the daily wage of two Haitian workers, and a good concrete recipe will have six 94lb bags of cement for every cubic yard of concrete produced. In Haiti, a small house would use more that 3 cubic yards of concrete, for just the foundation and wall supports.

When poverty is a part of this mixture, there is extreme pressure to skimp on some of the expensive cement in the recipe, weakening the result.  But the sad fact is that low cement volume is just the start of the problem.

The next issue involves the cheapest component used in the process; water.  Water has an enormous effect on concrete quality. Water that is dirty or that might be salty weakens the mix and corrodes the steel reinforcements.  But it is the amount of water in the mix that makes concrete the weakest. Good concrete uses a recipe of about 5-gallons of water per sack of Portland cement.

Much of the concrete produced for Haitian homes uses more water than is needed. They add water to make it easier to move the concrete from the mixing area to the building site using buckets. These “bucket-brigades” are used to scoop-up a couple of gallons of concrete mix in each pail for distribution down the line. The wetter the mix the easier it is to drag the bucket through the concrete for distribution. But, the wetter the mix, the weaker the resulting concrete

The next problem involves the sand and the stone. These two components are not as critical as too little cement or too much water. Still, taking steps to find good materials is important to concrete quality.

These components are not expensive, yet the quality can vary greatly. Sand from the beach has salts and corrodes steel. Sand with too much dirt is weak. Rock piles full of twigs or recycled rubble produces poor concrete. Because of the enormous volume of debris from the quake, there will be pressure to reuse the rubble to rebuild Haiti, but this will not be a good practice.

Now, let’s get back to the shovel, particularly when it is used as a concrete mixer

Logic and evidence point to the folly of shovels in producing consistent batches of concrete. This is because consistent concrete requires two things to succeed:

1. Accurate measuring of all the components in the recipe.
2. Consistent and adequate blending of these mixtures.

Buckets and shovels mixing on the ground can get close to accomplishing these two objectives, but will never produce the type of concrete that can be trusted to withstand an earthquake. In the industrialized world we don’t use the shovel to produce concrete anymore, because it has been proven to fail, time and again.

If tomorrow we where to have an earthquake that devastated the poorest neighborhoods of LA, we wouldn’t pass out shovels as concrete mixers. Yet we still collect money from well-meaning donors to help people who continue to be killed from the action of their shovels. Why?

We can do better by teaching them how to make better concrete. When they can’t afford to purchase enough cement, we can make up the difference with our charity.  When they don’t have access to a good concrete mixer, we can fund the purchase or provide the access. The technology is not hard to use, in fact if you can operate a shovel you can be trained to operate a mixer. Further, anyone who can learn a repetitive action, can follow a simple consistent recipe.

It is not that hard to raise the bar in concrete quality for places like Haiti. If we want to save them from a repeat story of earthquake destruction, it won’t take that much effort.  The fact is that when they have better tools, they will gladly put down their shovels.

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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17 Responses to Death by a thousand shovels

  1. ttoes says:

    I think you are on the right track. It is hard to imagine allowing such an outdated and inefficient method of mixing concrete. It seems pretty callous of us to let the practice continue when we know the end result (and have seen it so recently). We may try to justify it as using local materials and methods, but the disastrous effect will be the same – unneeded deaths.
    I think that auto safety glass might be a fair analogy. One hundred years ago, auto safety glass did not exist. When something hit a car window, glass shards became weapons and injured a lot of people. Though safety glass was first used in cars in the late 1920s, it did not become mandatory in all cars made in the U.S. until 1966. Can you imagine building cars for third world countries with standard plate glass to save money or use local materials?

  2. Scotty Concrete says:

    Accuracy is a great part of the equation while mixing, but so is consistency. Each batch needs to match the one before and the ones that follow. Hand in hand with that is education. The simpler any system is the easier it is to teach. Once taught the practice a cycle begins where quality materials put out a quality product. I think this is crucial in places like Haiti.

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  4. Elisabeth Feland says:

    Very much enjoyed your article. I spend a great deal of time in Haiti and have very dear friends there. I do not know that much about concrete other than knowing it is a very inferior type of concrete they deal with over there. Of course the way it is made has alot to do with it. I guess you could compare it to even making a cake. You would surely not add more of one ingredient to make it easier or stretch further without seeing a break down in the stucture of the cake. The same applies to even concrete.

  5. cementtrust says:

    Elisabeth,
    We thank you for sharing your experience from Haiti. It is sad that they don’t have the tools that we enjoy in our comfortable existence. With some training and some better tools, some day Haitian’s may be able to make their concrete “cake” better.

  6. Michele E. Hutchinson says:

    This is a well written, commonsence article. If the recipe for strong concrete structures doesn’t become law, Haiti will again, fall. I remember Harry Belafonte in his Calyso days singing “House Built on a Weak Foundation, Will not Stand”. Your company is in Haiti I assume. You should gather all companies like yours and some civil engineers to carry this information to the people and then get the people to demand strict building codes, legal permits to build, licensed builders, with honest supervisors and inspectors to evaluate construction. I still have the building permit hanging on my laundry room wall giving me legal permission to add on a 20 x 20 family room. I plan to sell my house and that permit remains with the dwelling. Keep on Pushing for Building Codes and there enforcement.

    • cementtrust says:

      Thank you for those kind words and your thoughts on playing by the rules.
      I am going to find the song by Harry Belafonte and put it here on the blog!
      I just wrote a post on building a house on a rock…

  7. Michele E. Hutchinson says:

    I forgot to say that I think the correct building tool and machinery will come with environmentally safe and nature prone building codes. Shovels will then be reduced to their real purpose. Educate the common work-a-day people and the poor on what is needed so that they can join and support you when strict codes are presented. Afterall they will want to be safer should there come a stronger earthquake. Educate, educate, educate especially the poor.

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  11. Duane says:

    After spending thirteen years working in Haiti doing maintenance and construction I feel I have a little knowledge of how many of the Haitians think. Many live for today’s immediate needs and don’t look to the future which creates a difficult situation in convincing them to follow good construction practices. The needs many times out weigh the good. I commend you on an excellent article on sound concrete production. I wish you good luck (Bon Kouraj) in following through with this.

    By the way, The buildings I built with 6 bag concrete are still standing in PAP.

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  13. Bob says:

    I’d like to see cheaper mixers designed that could be human powered in cases where the engine was broken or fuel was expensive. A pictogram of the optimum mixing recipe could be embossed on the side, with various numbers of buckets depicted beneath an image of one bag, alongside images of droplets, coarse aggregate, and fine aggregate.
    — Though an experienced used can measure fairly accurately with a #2 shovel, most people can’t, and a leveled bucket is a more accurate tool, but hard to lift. Some means of keeping the lift height low would be needed, some kind of levered hopper.
    — I shudder at the thought of micromanaging regulations being imposed on people in poor, often corrupt countries, taking away one of the few areas where they have control over their lives and giving bureaucrats new opportunities to demand bribes. Education empowers; regulation disempowers, and the emphasis should be on education and the provision of means. Many of the lives saved by strict building regulations will likely be lost eventually in the civil wars and revolutions which become more inevitable when one fosters totalitarian control. Treating people like farm animals to be managed undermines the good technical work of giving them the means to build safe houses.

    • cementtrust says:

      Thanks for you contribution Bob.
      One of the challenges of mixing concrete in any volume is the consistency of each batch and the torque that it requires to adequately blend the recipe. Even though a hand-operation would be less expensive, it is difficult to get the torque high enough to mix in any volume of concrete batch. The only solution is very small mixing chambers with low yield-rates. With the average small dwelling at about 3 to 5 yards of concrete, the volume of each batch becomes an issue.

      I also don’t like the opportunity of bureaucrats to receive bribes, but breaking the cycle of poorly constructed buildings is really the only way to stop the repetitive destruction caused by the crumbling of bad structures. I reject the notion that following building requirements, based upon good building practices, will cause society to fall into civil unrest. Further, we should turn skill into an enterprise that provides a job and a growing wealth within the local community. The means to build safe houses rests on the foundation of training, quality raw materials, appropriate equipment and building guidelines, not upon the current course that the “deadly shovels” represent.

  14. Quinn says:

    Howdy! This post couldn’t be written any better! Reading this post reminds me of my good old room mate! He always kept chatting about this. I will forward this write-up to him. Pretty sure he will have a good read. Thank you for sharing!

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